Gravity responsive optically variable encapsulated particles

Abstract

The present disclosure provides, in part, compositions comprising gravity responsive optically variable encapsuled (GROVE) particles and particle-based compositions that change optical properties in response to a force, e.g., gravity, mechanical agitation, magnetic fields, sound, etc., and methods of preparing and using the same.

Description

GRAVITY RESPONSIVE OPTICALLY VARIABLE ENCAPSULATED PARTICLESFIELD

[0001] The present disclosure relates, in part, to particles and particle-based compositions that change optical properties in response to a force, e.g., gravity, mechanical agitation, magnetic field, sound, or to a combination of ferees.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 598,637, filed November 14, 2023, the entire contents of which are incorporated by reference.BACKGROUND

[0003] Property-changing materials, such as color-shifting materials, are commercially available for a wide variety of applications from smart windows to tattoos, to freshness testing on perishable foods, authentication, brand security, product security, biosensors, and countless others. Invariably, a stimulus is required to initiate a change in color, which can be reversible or irreversible depending on the design of the materials and the intended use. Stimuli for the change in color include temperature, light, electric fields, magnetic fields, a chemical or biochemical entity (e.g. a class of molecules such as a sugar, or a specific molecule such as benzoic acid), and pressure, to name a few. Many of these stimuli have limitations. Specifically, effecting a color change requires ancillary devices or instrumentation (e.g., a magnet or means of creating a magnetic field, a heating element), or stimuli that may not be present in all circumstances (e.g. heat in a cold environment, UV light in a below-ground space). There remains a need for a reversible, colorshifting material that responds to instrument-free stimuli or actuation in a wider range of environments, at all temperatures and humidities, in all spaces indoor and outdoor, at all altitudes, and at all pressures. Likewise, there remains a need for reversible, color-shifting materials that are easily dispersed in a solvent or fluid.SUMMARY

[0004] Accordingly, the present disclosure provides, in part, compositions comprising encapsulated, optical-state-shifting particles that change that change color in response to stimulation, and return to their initial color in response to the force of gravity. These gravity-responsive optically-variable encapsulated (GROVE) particles comprise (i) one or more core particles comprising at least two materials of distinct density, (ii) at least two optically active agents, and (iii) a shell at least partially encapsulating the one or more core particles and configured to confine the one or more core particles a shell that is optically transparent toat least a portion of electromagnetic radiation between the frequencies of the x-ray / ultraviolet region (wavelengths greater than about 10 nm) and microwave / radio region (up to about 10 cm). In embodiments, the color change is initiated by a force acting on the particles that includes, but is not limited to, gravity, mechanical agitation, magnetic field / flux, or sound waves (acoustic force), while the return to an initial color state in the particles (e.g., relaxation) results from the force of gravity (e.g., restoring force).

[0005] In embodiments, the change in optical property is a change in color in the electromagnetic spectrum between about 300 nm and about 1200 nm, optionally about 380 nm to about 750 nm (e.g., the visible spectrum).

[0006] In embodiments, the outer shell comprises a dimension of about or at least 3 nm, about or at least 5 nm, about or at least about 10 nm, about or at least 20 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm, about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, or about or at least about 1000 pm, including sizes and size ranges therebetween.

[0007] In embodiments, the one or more core particles comprises a dimension of about or at least 5 nm, about or at least about 15 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or atleast about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm (1 pm), about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 250 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, or about or at least about 1000 pm, including sizes and size ranges therebetween.

[0008] In embodiments, the GROVE particle has a ratio of densities between the at least two materials in the one or more core particles is about or at least about 1 :1.01 , about or at least about 1 :1 .05, about or at least about 1 :1.1, about or at least about 1 :1.2, about or at least about 1 :1.3, about or at least about 1:1.4, about or at least about 1 :1.5, about or at least about 1 :2, about or at least about 1 :3, about or at least about 1 :4, about or at least about 1 :5, about or at least about 1 :6, about or at least about 1 :7, about or at least about 1 :8, about or at least about 1:9, about or at least about 1 :10, including ratios therebetween.

[0009] In embodiments, the optically active agents are disposed on, or incorporated into, the one or more core particles. In embodiments, the one or more core particles comprises (e.g., are composed of) materials which are optically active agents. In embodiments, the at least two materials comprise one or more of metals, metal oxides, metal nitrides, inorganic materials, silica, organic materials, organic polymers, inorganic polymers, biological polymers, synthetic polymers, and combinations thereof. In embodiments, the one or more core particles comprises two optically active agents, three optically active agents, four optically active agents, five optically active agents (e.g., 6, 7, 8, 9, or 10 or more optically active agents).

[0010] In embodiments, the one or more optically active agents exhibits a color in the visible electromagnetic spectrum and / or comprising an extinction, reflection, or scattering at a wavelength from about or at least about 300 nm to about or at least about 1200 nm. In embodiments, the GROVE particle exhibits a discernable optical effect within the visible spectrum. In embodiments, the color is one or more of white, black, red, orange, yellow, green, blue, indigo, and violet, or a color shade or hue therebetween.

[0011] In embodiments, the one or more optically active agents comprises a dye. In embodiments, the dye comprises one or more of Rhodamine B, Congo Red, Crystal Violet, Methylene Blue, Acridine Orange, Nile Red, Malachite Green, Eosin Y, Cresol Red, Fluorescein, and Indigo.

[0012] In embodiments, the one or more optically active agents comprises a pigment.

[0013] In embodiments, the one or more optically active agents comprise pigments commonly used in printing inks, including but not limited to Pigment Blue 15:3, Pigment Red 122, Pigment Violet 19, Pigment Yellow 12, 13, or 74), Pigment Black 7, Pigment White 6, Pigment Red 57:1. Pigment Orange 34 or 36, Pigment Green 7 - Phthalocyanine Green), Pigment Blue 15, Pigment Violet 23, Pigment Brown 23 or 25, Pigment Yellow 42, Pigment Brown 7, Pigment Red 101 , and Pigment Blue 29.

[0014] In embodiments, the pigment comprises a water-soluble pigment. In embodiments, the water- soluble pigment comprises one or more of anthocyanin, anthraquinone, carotenoid, violacein, melanin, pyocyanin, prodiginines, asperversin, benzoquinone, anthraquinone, and derivatives thereof.

[0015] In embodiments, the pigment comprises a pigment, e.g., such as Pigment Yellow 83 or Pigment Yellow 176, that is dispersible in an organic solvent.

[0016] In embodiments, the pigment comprises one or more of Titanium White (PW6), Zinc White (PW4), Carbon Black (PBk7), Mars Black (PBk11 ), Iron Oxide Red (PR101), Cadmium Red (PR108), Alizarin Crimson (PR83), Cadmium Orange (PO20), Cadmium Yellow (PY35), Lemon Yellow (PY3), Chromium Green Oxide (PG17), Phthalo Green (PG7), Ultramarine Blue (PB29), Cobalt Blue (PB28), Cerulean Blue (PB35), Prussian Blue (PB27), Burnt Sienna (PBr7), Raw Umber (PBr7), Raw Sienna (PBr7), and Yellow Ochre (PY43). In embodiments, the pigment is an organic pigment or an inorganic pigment.

[0017] In embodiments, the organic pigment or inorganic pigment is a white pigment. In embodiments, the white pigment is one or more of lead white (2PbCO3 Pb(OH)2), kaolin, silica (SiOz), Titanium dioxide (TiOz / rutile and anatase), zinc oxide (ZnO), zinc sulfide (ZnS), and / or lithopone (ZnS + BaSO4).

[0018] In embodiments, the organic pigment or inorganic pigment is a black pigment. In embodiments, the black pigment is one or more of coal (charcoal), groutite (a-MnOOH), manganite (y-MnOOH), hausmannite (MnaC ), Carbon black, graphene, graphite, iron oxide black (FesCh), and / or spinel black (CuCrzCU).

[0019] In embodiments, the organic pigment or inorganic pigment is a colored pigment.

[0020] In embodiments, the colored pigment comprises a yellow pigment. In embodiments, the yellow pigment comprises one or more of yellow ochre (a-FeOOH), auric pigment (AS2S3), lead ochre (PbO), lead tin yellow (PbzSnCU, PbSnzSiO ), Naples yellow (Pb(SbO3)z), zinc yellow (ZnzCrO^, Indian yellow (C19H16O10), Iron oxide yellow (a-FeOOH), chromium titanium yellow ((Ti,Cr,Sb)Oz), nickel titanium yellow ((Ti, Ni,Sb)Oz), lead yellow (PbCrCh), cadmium yellow (CdS), bismuth yellow (BiVCh).

[0021] In embodiments, the colored pigment comprises a red pigment. In embodiments, the red pigment comprises one or more of red ocher (o-Fe2O3), Terra di Siena (o-Fe2O3), vermilion (HgS), lead red (PbsCk), alizarin madder varnish, alizarin red (C^HsCU), Iron oxide red (a-Fe2O3), molybdate red (Pb(Cr,S,Mo)O4), cadmium red (Cd(S,Se)).

[0022] In embodiments, the colored pigment comprises a green pigment. In embodiments, the green pigment comprises one or more of green earth (Fe silicates), Schweinfurt green (C4H6AS6CU4O16), chromium oxide green (Cr2O3), chromium oxide hydrate green (CrOOH), cobalt green (CtoTiCh).

[0023] In embodiments, the colored pigment comprises a blue pigment. In embodiments, the blue pigment comprises one or more of lazurite (lapis lazuli), Egyptian blue (CaCuSi40io), azurite (2CUCO3'CU(OH)2), malachite (CuCO3-Cu(OH)2), cobalt blue (COAI2O4), cobalt blue (COAI2O4), ultramarine blue: (Na6AI6Si6O24(NaSn)), iron bluea (K[FelllFell(CN)6] xH2O).

[0024] In embodiments, the colored pigment comprises a brown pigment. In embodiments, the brown pigment comprises one or more of burnt umber (Fe2O3 xMnO2), brown ocher (o-Fe2O3 + Mn oxides), limonite (mixture of different Fe oxides).

[0025] In embodiments, the pigment is one or more of an oxide or oxide hydroxide pigment (TiO2, ZnO, a-Fe2O3, o-FeOOH, y-Fe2O3, FesCU, CtoOs, CrOOH, PbO, PB3O4, MnsO4, -MnOOH, Sb2O3), a complex oxide pigment (C0AI204, CuCr2O4, Co2TiO4, (Ti,Ni,Sb)O2, (Ti,Cr,Sb)C>2), a carbonate hydroxide pigment (2PbCO3'Pb(OH)2, 2CuCO3-Cu(OH)2, CUCO3-CU(OH)2), a sulfide / selenide pigment (ZnS, CdS, Cd(S,Se), CdSe, y-Ce2S3, HgS, AS2S3), a chromate / molybdate pigment (PbCrO4, Pb(Cr,S)O4, Pb(Cr,S,Mo)O4, ZnCrO4, BaCrO4, SrCrO4), a vanadate pigment (BiVC , 4BiVO4'3Bi2MoO6), a stannate pigment (Pb2SnO4, PbSn2SiO / , Co2SnO4, CoSnOs), a phosphate pigment (Co3(PO4)2), an antimonate pigment (Pb(SbO3)2), an arsenate pigment (Cu(AsO3)2), an ultramarine pigment (Na6Al6SieO24(NaSn)), a hexacyanidoferrate / hexacyanoferrate pigment (K[FelllFell(CN)6]-xH2O (x = 14-16)), an oxonitride pigment (CaTaO2N, LaTaOISb), an elemental-based pigment (C, Al, Cu, Cu / Zn, Au), a doped metal-based pigment, a spinel-based pigment, and / or a rutile-based metal pigment.

[0026] In embodiments, the inorganic pigment is one or more of a “special optical material,” such as a transparent effect pigment, goniochromatic pigment, pearlescent pigment, metallic pigment, interference pigment, metallic effect pigment, fluorescent pigment, luminescent pigment, phosphorescent pigment, magnetic pigment, anticorrosive pigment, anisotropic material, and / or plasmonic material. In embodiments, the metallic pigment comprises one or more of aluminum, bronze, and copper metallic pigment. Inembodiments, the pearlescent pigment comprises one or more of mica, titanium dioxide, and bismuth oxychloride. In embodiments, the fluorescent pigment comprises one or more fluorescent dyes and / or pigments comprising a fluorescent mineral. In embodiments, the phosphorescent pigment comprises zinc sulfide and / or strontium aluminate. In embodiments, the interference pigment comprises titanium dioxidecoated mica and / or aluminum oxide-coated mica. In embodiments, the one or more optically active agents comprises an anisotropic particle. In embodiments, the anisotropic particle comprises a nanoparticle of the one or more metals, optionally comprising a nanorod of one or more of gold (Au), silver (Au), and aluminum (Al). In embodiments, the at least two optically active agents comprise a plasmonic material. In embodiments, the plasmonic material comprises a pigment, particle, foil, and / or film. In embodiments, the plasmonic material comprises a polymer-film loaded with noble metal nanoparticles. In embodiments, the goniochromatic pigment comprises aluminum coated with magnesium fluoride embedded in chromium.

[0027] In embodiments, the GROVE particle is composed of a magnetic material and / or responds to a magnetic field. In embodiments, at least one of the at least two materials in the core particle(s) comprises a magnetic material. In embodiments, the magnetic material is ferromagnetic, ferrimagnetic, antiferromagnetic, diamagnetic, paramagnetic, superparamagnetic, and / or antiferromagnetic. In embodiments, the magnetic material comprises one or more of an inorganic, organic, carbon-based, or biomolecule-based magnetic material. In embodiments, the magnetic material comprises one or more of iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), manganese (Mn), chromium (Cr), samarium (Sm), alloys or oxides thereof; alloys, intermetallic, and / or oxides of Fe, Co, Ni, Zn, Mn, Sm; oxides are of iron, Fe2Oa, FeO, and / or Fe3O4; ferrite material and / or doped materials of Co, Ni, Zn, and / or Mn:FexOy, and / or magnetitetetracyanoethylene (TCNE) salts, [Fe(C5Me5)2]+|TCNE]«-, Li[TCNE], [MnllTPP]|TCNE]« (TPP = tetraphenylporphyrin), [Fell(TCNE)(NCMe)2][FelllCl4], Mnll(TCNE)l(OH2), Mnll(TCNE)[C4(CN)8]i / 2, Fe(TCNE)[C4(CN)8]i / 2, Mnll(TCNE)3 / 2(l3)i / 2, VII|TCNE]x (x « 2), C HsCINsSe^ magnetic organic polymers, and polymer-bound magnetic materials.

[0028] In embodiments, one or more of the at least two materials, the optically active agents, and / or the outer shell is or comprises a polymeric material. In embodiments, one or more of the at least two materials, the optically active agents, and / or the outer shell is or comprises silica (S1O2).

[0029] In embodiments, the polymeric material comprises one or more of a plastic, acrylic resin, styrene acrylic copolymer, vinyl acetate ethylene copolymer, polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, polyurethane, epoxy resin, alkyd resin, cellulose acetate, silicone resin, a fluoropolymer resin, chlorinatedrubber, a copolymer derived from maleic anhydride, ethylene vinyl acetate, polyethylene, polypropylene, polyamides (nylons), polyester resins, polybutadienes, thermally responsive polymers, latex, hydrocarbons, crude oil derivatives and / or petroleum derivatives, poloxamers, styrene-butadiene block copolymers, polymethylmethacrylate, polybutylmethacrylate, poly(tert-butyl acrylate)-poly(3-(triethoxysilyl)propyl methacrylate) (PtBA-PTPM), polystyrene latex polymer, carboxylated latex polymer, aminated latex polymer, colored polystyrene polymer (dye-infused and / or pigment-infused), colored polystyrene-based carboxylated latex polymer (dye-infused and / or pigment-infused), fluorescent polystyrene-based polymers, fluorescent polystyrene-based carboxylated latex polymers, fluorescent aminated polystyrene-based polymer, surfactant-free polystyrene, carboxylated surfactant-free polymer, polymethyl methacrylate (PMMA) latex polymer, and / or divinylbenzene-crosslinked polystyrene latex, plasticized polyvinyl chloride, plasticized nylon, plasticized polyethylene terephthalate, polyacrylonitrile, polychlorotrifluoroethylene, poly-4, 4'- isopropylidenediphenylene carbonate, polyethylene vinyl ester, polyvinyl chloride-diethyl fumarate, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers, acrylonitrile butadiene styrene, epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer, cyclic olefin polymer, poly dimethyl siloxane, poly ether ester ketone, polyetherimide, and combinations thereof.

[0030] In embodiments, the polymeric material of either the optically active agents or the outer shells are functionalized with pendant functional groups. In embodiments, the pendant functional groups comprise alcohols, ethers, aldehydes, ketones, carboxylates, amides, esters, amines, alkyl amines, dialkyl amines, cyanides, isocyanides, thiethers, sulfhydryls, or thioesters.

[0031] In embodiments, one or more of the at least two materials, the at least two optically active agents, and / or the outer shell is or comprises one or more naturally occurring polymer and / or biological polymer. In embodiments, the one or more naturally occurring polymer and / or biological polymer comprises one or more of a nucleic acid (DNA, RNA), amino acid (peptide, protein), polysaccharide, and lipid.

[0032] In embodiments, the outer shell comprises one or more materials. In embodiments, the outer shell comprises one or more layers. In embodiments, the outer shell comprises at least a portion that is opaque. In embodiments, the outer shell comprises a single, uniform thickness and / or varying thicknesses. In embodiments, the outer shell comprises a thickness of about or at least about 1 nm, about or at least about 5 nm, about or at least about 10 nm, about or at least about 15 nm, about or at least about 20 nm, about or at least about 25 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about50 nm, about or at least about 100 nm, about or at least about 200 nm, about or at least about 300 nm, about or at least about 400 nm, about or at least about 500 nm, about or at least about 600 nm, about or at least about 700 nm, about or at least about 800 nm, about or at least about 900 nm, about or at least about 1 pm, about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 10 pm, about or at least about 15 pm, about or at least about 20 pm, about or at least about 25 pm, about or at least about 30 pm, about or at least about 35 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, about or at least about 600 pm, about or at least about 700 pm, about or at least about 800 pm, about or at least about 900 pm, or about or at least about 1000 pm, including thicknesses therebetween.

[0033] In embodiments, the outer shell comprises layer-by-layer assembled materials. In embodiments, the outer shell is formed by etching and / or the use of swellable materials.

[0034] In embodiments, the outer shell is configured to filter or select for (e.g., have selective transmissibility) a wavelength or ranges of wavelengths of radiation. In embodiments, the outer shell is configured to transmit a percentage of electromagnetic radiation of about or at least about 100%, about or at least about 99%, about or at least about 98%, about or at least about 97%, about or at least about 96%, about or at least about 95%, about or at least about 94%, about or at least about 93%, about or at least about 92%, about or at least about 91%, about or at least about 90%, about or at least about 85%, about or at least about 80%, about or at least about 75%, about or at least about 70%, about or at least about 65%, about or at least about 60%, about or at least about 55%, about or at least about 50%, about or at least about 40%, about or at least about 30%, about or at least about 20%, about or at least about 10%, about or at least about 5%, about or at least about 4%, about or at least about 3%, about or at least about 2%, about or at least about 1 %, about or at least about 0.5%, about or at least about 0.4%, about or at least about 0.3%, about or at least about 0.2%, about or at least about 0.1%, about or at least about 0.05%, about or at least about 0.04%, about or at least about 0.03%, about or at least about 0.02%, about or at least about 0.01 %, about or at least about 0.005%, or about or at least about 0.001%, including percentages therebetween, relative to the intensity or amount of electromagnetic radiation that impinges on the outer shell.

[0035] In embodiments, the outer shell comprises one or more inorganic materials. In embodiments, the one or more inorganic materials comprise one or more of alumina, silica, titania, silicon nitride, zirconia, copper oxide, iron oxide, cobalt oxide, silver, gold, aluminum, copper, tin oxide, nickel oxide, lead oxide,glass, quartz, sapphire, inorganic glasses, diamond, diamond-like materials, zinc oxide, and manganese oxide.

[0036] In embodiments, the one or more core particles comprises a Janus particle (JP).

[0037] In embodiments, the outer shell fully encapsulates the core particle, resulting in a bounded internal volume. In embodiments, the bounded internal volume comprises one or more of a gas or mixture of gases, a liquid or mixture of liquids, a polymer or mixture of polymers, a semisolid, and a solid material. In embodiments, the gas is atmospheric air. In embodiments, the liquid comprises an aqueous liquid, organic liquid, a mixed aqueous-organic mixture, a polymer, and / or a gel. In embodiments, the liquid comprises one or more additives, preservatives, anti-oxidants, lubricants, emulsifiers, stabilizers, thickeners, anti-foaming agents, humectants, anti-bacterial agents, anti-caking agents, inorganic salts, pH adjusters, pH buffers, and rheology modifiers. In embodiments, the lubricant comprises one or more of mineral oil, synthetic oil, grease, a silicone-based lubricant, a graphite-based lubricant, molybdenum disulfide, vegetable oils, and TEFLON- based lubricants. In embodiments, the one or more gas or gases, liquid or liquids, polymer or polymers, semisolids, and solid materials occupies about or up to about 99.5%, about or up to about 99%, about or up to about 97%, about or up to about 96%, about or up to about 95%, about or up to about 94%, about or up to about 93%, about or up to about 92% about or up to about 91% about or up to about 90%, about or up to about 85%, about or up to about 80%, about or up to about 70%, about or up to about 60%, about or up to about 50%, about or up to about 40%, about or up to about 30%, about or up to about 20%, about or up to about 15%, about or up to about 10%, about or up to about 9%, about or up to about 8%, about or up to about 7%, about or up to about 6%, about or up to about 5%, about or up to about 4%, about or up to about 3%, about or up to about 2%, about or up to about 1 %, about or up to about 0.5%, about or up to about 0.2%, about or up to about 0.1%, about or up to about 0.01%, or about or up to about 0.001% of the bounded internal volume outside of the one or more core particles, including volumes therebetween.

[0038] In embodiments, the outer shell is porous and / or discontinuous. In embodiments, the pores and / or discontinuities comprise about or up to about 0.001 %, or about or up to 0.01 , or about or up to 0.1 %, about or up to about 1%, about or up to about 10%, or about or up to about 50% or more of a total surface area of the outer shell, including surface area ranges therebetween.

[0039] In embodiments, the GROVE particle comprises a single core particle. In embodiments, the GROVE particle comprises about or at least about 2 core particles, about or at least about 3 core particles, about or at least about 4 core particles, about or at least about 5 core particles, about or at least about 6 coreparticles, about or at least about 7 core particles, about or at least about 8 core particles, about or at least about 9 core particles, about or at least about 10 core particles, about or at least about 12 core particles, about or at least about 14 core particles, about or at least about 16 core particles, about or at least about 18 core particles, about or at least about 20 core particles, about or at least about 25 core particles, including numbers of core particles therebetween.

[0040] In embodiments with 2 or more core particles, the particles are equivalent in size. In embodiments with 2 or more core particles, the particles are monodisperse. In embodiments with 2 or more core particles, the particles are differently-sized. In embodiments with 3 or more core particles, the particles are polydisperse. In embodiments with 3 or more core particles, there are two or more sets of monodisperse particles.

[0041] In embodiments having two or more GROVE particles, the GROVE particles each exhibit substantially equivalent optical properties (and optical property changes in response to stimuli). In embodiments having two or more GROVE particles, the GROVE particles each exhibit distinct optical properties.

[0042] In embodiments, the one or more core particles are configured to transition from an equilibrium position to one or more non-equilibrium positions.

[0043] In embodiments, the one or more core particles re-establishes the equilibrium position from the one or more non-equilibrium positions due to a restoring force. In embodiments, the restoring force comprises gravity.

[0044] In embodiments, the re-establishment of the equilibrium position (e.g., relaxation) occurs in about or less than about 1 ms, about or less than 2 ms, about or less than 3 ms, about or less than 4 ms, about or less than 5 ms, about or less than 6 ms, about or less than 7 ms, about or less than 8 ms, about or less than 9 ms, about or less than 10 ms, about or less than 12 ms, about or less than 14 ms, about or less than 16 ms, about or less than 18 ms, about or less than 20 ms, about or less than 25 ms, about or less than 30 ms, about or less than 35 ms, about or less than 40 ms, about or less than 45 ms, about or less than 50 ms, about or less than 55 ms, about or less than 60 ms, about or less than 65 ms, about or less than 70 ms, about or less than 75 ms, about or less than 80 ms, about or less than 85 ms, about or less than 90 ms, about or less than 95 ms, about or less than 100 ms, about or less than 125 ms, about or less than 150 ms, about or less than 175 ms, about or less than 200 ms, about or less than 250 ms, about or less than 300 ms, about or less than 350 ms, about or less than 350 ms, about or less than 400 ms, about or less than 450 ms,about or less than 500 ms, about or less than 600 ms, about or less than 700 ms, about or less than 800 ms, about or less than 900 ms, about or less than 1 s, about or less than 2 s, about or less than 3 s, about or less than 4 s, about or less than 5 s, about or less than 6 s, about or less than 7 s, about or less than 8 s, about or less than 9 s, about or less than 10 s, about or less than 20 s, about or less than 30 s, about or less than 40 s, about or less than 50 s, or about or less than 1 min, including times and time ranges therebetween.

[0045] In embodiments, collections of GROVE particles exhibit different relaxation times. In embodiments, the relaxation times for different GROVE particles vary on the order of 0.01 s (milliseconds), 0.1 s (tenths of a second), or by seconds.

[0046] In embodiments, the GROVE particle and / or one or more core particles therein comprise a shape substantially similar to one or more of a sphere, a truncated teardrop shape, champagne flute shape, wine glass shape, round-bottomed shape, tumbler shape, egg-shape, paraboloid, prolate hemispheroid, oblate hemispheroid, hemispherical, elliptical, cylindrical, trigonal pyramid, pentagonal pyramid, hexagonal pyramid, a regular polygonal shape with a truncated portion, a truncated square pyramid, a truncated cone, and a truncated cone where the top plane and bottom plane are not parallel.

[0047] In embodiments, of the at least two materials of distinct density, a denser material occupies less volume of the one or more core particles than a less dense material. In embodiments, of the at least two materials of distinct density a less dense material occupies about or at least about 0.01 %, 0.1 %, 1% 2% 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12% 14%, 16%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, or more than 90% of the one or more core particles. In embodiments, of the at least two materials of distinct density a denser material occupies about or at least about 1 %, 2% 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12% 14%, 16%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, or more than 90% of the one or more core particles.

[0048] In embodiments, the GROVE particle, the one or more core particles, and / or the outer shell comprise a shape having one or more axes of symmetry. In embodiments, the GROVE particle, the one or more core particles, and / or the outer shell comprise an asymmetrical shape.

[0049] In embodiments, an outer and / or inner surface of the outer shell and / or an outer surface of the one or more particles comprises one or more roughness features. In embodiments, the one or more roughness features is a variation in a surface smoothness that alters the degree of scattering and / or reflectivity of the surface at one or more wavelengths.

[0050] In embodiments, the one or more roughness features is regularly or irregularly shaped. In embodiments, the one or more roughness features appears in a regular and / or irregular pattern.

[0051] In embodiments, the one or more core particles and / or the outer shell is coated with one or more coating materials. In embodiments, the one or more coating materials is or comprises a chemical functionalization covering at least a portion of the outer shell. In embodiments, the one or more coating materials is or comprises a swellable material covering the core particle. In embodiments, the one or more coating materials comprises one or more organic substance, inorganic substance, biological substance, and combinations thereof. In embodiments, the one or more coating materials comprises one or more of a lubricant, surface treatment, and polishing agent. In embodiments, the one or more lubricant, surface treatment, and polishing agent comprises one or more of polytetrafluoroethylene (PTFE), hydroxylated selfassembled monolayers, vitreous enamel, ceria (cerium oxide), ceramics, anodized metals, and silica.

[0052] In embodiments, the outer shell of the GROVE particle is functionalized to make the particles more hydrophobic. In embodiments, the outer shell of the GROVE particle is functionalized to make the particles more hydrophilic.

[0053] In embodiments, the core particle is suspended or otherwise shares an internal volume with a fluid or liquid.

[0054] In embodiments, the force comprises one or more of gravity, a mechanical force, an acoustic force (e.g., sound), a magnetic force (e.g., magnetic field / flux), an electrical field, and combinations thereof.

[0055] In embodiments, the acoustic force comprises a sound having a frequency or range of frequencies comprising a range of <20 Hz range, a range of about or at least about 20 Hz to about or at least about 20,000 Hz (20 kHz), and / or in a range of about or at least about 20 kHz to about or at least about 200,000,000 Hz (200 MHz). In embodiments, the frequency or range of frequencies is about or at least about 10 Hz, about or at least about 20 Hz, about or at least about 30 Hz, about or at least about 40 Hz, about or at least about 50 Hz, about or at least about 60 Hz, about or at least about than 70 Hz, about or at least about 80 Hz, about or at least about 90 Hz, about or at least about 100 Hz, about or at least about 110 Hz, about or at least about 120 Hz, about or at least about 130 Hz, about or at least about 140 Hz, about or at least about 150 Hz, about or at least about 160 Hz, about or at least about 170 Hz, about or at least about 180 Hz, about or at least about 190 Hz, about or at least about 200 Hz, about or at least about 210 Hz, about or at least about 220 Hz, about or at least about 230 Hz, about or at least about 240 Hz, about or at least about 250 Hz, about or at least about 260 Hz, about or at least about 280 Hz, about or at least about 300 Hz, aboutor at least about 320 Hz, about or at least about 340 Hz, about or at least about 360 Hz, about or at least about 380 Hz, about or at least about 400 Hz, about or at least about 420 Hz, about or at least about 440 Hz, about or at least about 460 Hz, about or at least about 480 Hz, about or at least about 500 Hz, about or at least about 750 Hz, about or at least about 1 ,000 Hz, about or at least about 1 ,250 Hz, about or at least about 1 ,500 Hz, about or at least about 1,750 Hz, about or at least about 2,000 Hz, about or at least about 2,250 Hz, about or at least about 2,500 Hz, about or at least about 2,750 Hz, about or at least about 3,000 Hz, about or at least about 3,250 Hz, about or at least about 3,500 Hz, about or at least about 3,750 Hz, about or at least about 4,000 Hz, about or at least about 4,500 Hz, about or at least about 4,500 Hz, about or at least about 5,000 Hz, about or at least about 5,500 Hz, about or at least about 6,000 Hz, about or at least about 8,000 Hz, about or at least about 10,000 Hz, about or at least about 12,000 Hz, about or at least about 14,000 Hz, about or at least about 16,000 Hz, about or at least about 18,000 Hz, about or at least about 20,000 Hz, including frequencies and frequency ranges therebetween.

[0056] In embodiments, the acoustic force comprises an intensity of about or at least about 0.25 decibels (dB), about or at least about 0.50 dB, about or at least about 0.75 dB, about or at least about 1 dB, about or at least about 2 dB, about or at least about 3 dB, about or at least about 4 dB, about or at least about 5 dB, about or at least about 6 dB, about or at least about 7 dB, about or at least about 8 dB, about or at least about 9 dB, about or at least about 10 dB, about or at least about 20 dB, about or at least about 30 dB, about or at least about 40 dB, about or at least about 50 dB, about or at least about 60 dB, about or at least about 70 dB, about or at least about 80 dB, about or at least about 90 dB, about or at least about 100 dB, about or at least about 110 dB, about or at least about 120 dB, about or at least about 130 dB, about or at least about 140 dB, or about or at least about 150 dB, including intensities and intensity ranges therebetween.

[0057] In embodiments, the acoustic force comprises a duration of about or at least about 0.01 second (s), about or at least about 0.02 s, about or at least about 0.03 s, about or at least about 0.04 s, about or at least about 0.05 s, about or at least about 0.06 s, about or at least about 0.07 s, about or at least about 0.08 s, about or at least about 0.09 s, about or at least about 0.1 s, about or at least about 0.15 s, about or at least about 0.20 s, about or at least about 0.25 s, about or at least about 0.30 s, about or at least about 0.35 s, about or at least about 0.40 s, about or at least about 0.45 s, about or at least about 0.50 s, about or at least about 0.55 s, about or at least about 0.60 s, about or at least about 0.65 s, about or at least about 0.7 s, or about or at least about 0.8 s, about or at least about 0.9 s, about or at least about 1 s, about or at least about 1.1 s, about or at least about 1.2 s, about or at least about 1.3 s, about or at least about 1.4 s, about or at least about 1 .5 s, or about or at least 2.0 seconds, including durations and duration ranges therebetween.

[0058] In embodiments, the acoustic force is generated at a distance from the GROVE of about or at least about 0.0001 m, about or at least about 0.0005 m, about or at least about 0.001 m, about or at least about 0.002 m, about or at least about 0.003 m, about or at least about 0.004 m, about or at least about 0.005 m, about or at least about 0.006 m, about or at least about 0.007 m, about or at least about 0.008 m, about or at least about 0.009 m, about or at least about 0.01 m, about or at least about 0.02 m, about or at least about 0.03 m, about or at least about 0.04 m, about or at least about 0.05 m, about or at least about 0.06 m, about or at least about 0.07 m, about or at least about 0.08 m, about or at least about 0.09 m, about or at least about 0.1 m, about or at least about 0.2 m, about or at least about 0.3 m, about or at least about 0.4 m, about or at least about 0.5 m, about or at least about 1 .0 m, about or at least about 2.0 m, about or at least about 3 m, about or at least about 4 m, about or at least about 5 m, or greater than 5 m, including distances and distance ranges therebetween.

[0059] In embodiments, the one or more core particles comprise a magnetic material and the one or more core particles move as a function of exposure to a magnetic force, and a restoring force comprising gravity.

[0060] In aspects, described herein is a composition comprising gravity-responsive optically-variable encapsulated (GROVE) particles.

[0061] In embodiments, the composition comprises GROVE particles suspended in a liquid or carrier fluid or ink. In embodiments, the liquid comprises a solvent or dispersing agent. In embodiments, the liquid incorporates one or more of an emulsifier, surfactant, solvent, humectant, viscosity modifier, salt, rheological agent, anti-microbial agent, pH adjuster, solvent buffer, binder, resin, glue, gloss additive, adhesion additive, wax, slip agent, leveling agent, plasticizer, defoamer, anti-settling agent, biocide, chelating agent, conductive agents, drying accelerator, pigment, dye, wetting agent, anti-wetting agent, UV stabilizer, drying accelerator, suspending agent, optical brightener, matting agent, biological polymer, synthetic polymer, and organic molecule. In embodiments, the GROVE particles are present in a concentration of about or less than about 0.001% (w / v), about or less than about 0.1% (w / v), about or less than about 0.5% (w / v), about or less than about 1 % (w / v), about or less than about 2% (w / v), about or less than about 3% (w / v), about or less than about 4% (w / v), about or less than about 5% (w / v), about or less than about 6% (w / v), about or less than about 7% (w / v), about or less than about 8% (w / v), about or less than about 9% (w / v), about or less than about 10% (w / v), about or less than about 12% (w / v), about or less than about 14% (w / v), about or less than about 16% (w / v), about or less than about 18% (w / v), about or less than about 20% (w / v), about or less thanabout 25% (w / v), about or less than about 30% (w / v), about or less than about 35% (w / v), about or less than about 40% (w / v), about or less than about 50% (w / v), about or less than about 60% (w / v), or about or less than about 70% (w / v). In embodiments, the GROVE particles are present in a concentration of about or less than about 0.001 % (v / v), about or less than about 0.1 % (v / v), about or less than about 0.5% (v / v), about or less than about 1 % (v / v), about or less than about 2% (v / v), about or less than about 3% (v / v), about or less than about 4% (v / v), about or less than about 5% (v / v), about or less than about 6% (v / v), about or less than about 7% (v / v), about or less than about 8% (v / v), about or less than about 9% (v / v), about or less than about10% (v / v), about or less than about 12% (v / v), about or less than about 14% (v / v), about or less than about16% (v / v), about or less than about 18% (v / v), about or less than about 20% (v / v), about or less than about25% (v / v), about or less than about 30% (v / v), about or less than about 35% (v / v), about or less than about40% (v / v), about or less than about 50% (v / v), about or less than about 60% (v / v), or about or less than about 70% (v / v), including concentrations and concentration ranges therebetween.

[0062] In embodiments, the composition comprises GROVE particles arranged in an array on a substrate. In embodiments, the substrate comprises a thin film, plastic, polymer, and / or paper substrate. In embodiments, the array is a monolayer of particles. In embodiments, the array comprises two or more layers of particles. In embodiments, the GROVE particles are sandwiched between two or more substrate layers. In embodiments, the optical effect is different when viewed from above compared to when viewed from below a plane of GROVE particles arranged in or on the substrate and / or film, optionally wherein the plane of GROVE particles are arranged between or on a transparent substrate or film-based substrate. In embodiments, the GROVE particles are suspended, crosslinked, or embedded in a material (e.g., thermally- responsive, UV-crosslinkable, etc., material).

[0063] In embodiments, the percentage of a surface (or a region of a surface) covered by GROVE particles is about or less than 0.01%, about or less than 0.1%, about or less than 1 %, about or less than 2%, about or less than 3%, about or less than 4%, about or less than about 5%, about or less than about 10%, about or less than about 15%, about or less than about 20%, about or less than about 25%, about or less than about 30%, about or less than about 35%, about or less than about 40%, about or less than about 45%, about or less than about 50%, about or less than about 55%, about or less than about 60%, about or less than about 65%, about or less than about 70%, about or less than about 75%, about or less than about 80%, about or less than about 85%, about or less than about 90%, about or less than about 95%, or about or less than about 99%, including surface areas therebetween.

[0064] In embodiments, at least a portion of the substrate is transparent to at least a portion of the visible electromagnetic (EM) spectrum and / or opaque. In embodiments, the substrate comprises a material of one or more of glass, sapphire, diamond, silicon, organic polymers, organic materials, biological polymers, metal oxides, quartz, plastic, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers (TPE), acrylonitrile butadiene styrene (ABS), epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer (COC) cyclic olefin polymer (COP), poly dimethyl siloxane (PDMS), poly ether ester ketone (PEEK), polyetherimide (ULTEM) and nylon.

[0065] In embodiments, the GROVE particles are disposed upon the substrate and / or embedded between two or more substrates. In embodiments, the thickness of the GROVE particles and the substate is about or less than about 1 pm, about or less than about 2 pm, about or less than about 3 pm, about or less than about 4 pm, about or less than about 5 pm, about or less than about 6 pm, about or less than about 7 pm, about or less than about 8 pm, about or less than about 9 pm, about or less than about 10 pm, about or less than about 12 pm, about or less than about 13 pm, about or less than about 14 pm, about or less than about 15 pm, about or less than about 16 pm, about or less than about 17 pm, about or less than about 18 pm, about or less than 19 pm, about or less than about 20 pm, about or less than about 21 pm, about or less than about 22 pm, about or less than about 23 pm, about or less than about 24 pm, about or less than about 25 pm, about or less than about 26 pm, about or less than about 27 pm, about or less than about 28 pm, about or less than about 29 pm, about or less than about 30 pm, about or less than about 31 pm, about or less than about 32 pm, about or less than about 33 pm, about or less than about 34 pm, about or less than about 35 pm, about or less than about 36 pm, about or less than about 37 pm, about or less than about 38 pm, about or less than about 39 pm, about or less than about 40 pm, about or less than about 41 pm, about or less than about 42 pm, about or less than about 43 pm, about or less than about 44 pm, about or less than about 45 pm, about or less than about 46 pm, about or less than about 47 pm, about or less than about 48 pm, about or less than about 49 pm, about or less than about 50 pm, about or less than about 55 pm, about or less than about 60 pm, about or less than about 65 pm, about or less than about 70 pm, about or less than about 75 pm, about or less than about 80 pm, about or less than about 90 pm, about or less than about 100 pm, about or less than about 200 pm, about or less than about 500 pm, or about or less than about 1 mm, including thicknesses therebetween.

[0066] In embodiments, the substrate comprises one or more structural features comprising one or more of posts, detents, hemispheres, regular shapes, irregular shapes, grooves, bumps, indentations, prisms, walls, barriers, and roughness features. In embodiments, the structural features are arranged in apatern and / or are arranged in a non-patered orientation. In embodiments, the substrate is planar and / or non-planar.

[0067] In embodiments, the composition exhibits a change in one or more optical properties as a function of exposure to a force (e.g., stimuli). In embodiments, the force comprises one or more of gravity, a mechanical force, an acoustic force, a magnetic force, and an electrical field. In embodiments, the composition exhibits a change in color as a function of exposure to sound. In embodiments, the composition exhibits a change in color as a function of exposure to a magnetic field. In embodiments, the composition exhibits a change in color as a function of exposure to a mechanical force.

[0068] In aspects, described herein is a material for use in authentication. In embodiments, the material comprises providing a formulation of gravity-responsive optically-variable encapsulated (GROVE) particles, wherein the formulation comprises a fluid, suspension, ink, liquid film, adhesive, and / or material thereof; a foil, film, thin plastic, paper, and / or material thereof; or a fiber, thread, yarn, twine, and / or material thereof.

[0069] In aspects, described herein is a method for authentication of an object, a material, a substance and / or a surface. In embodiments, the method comprises (a) tagging or otherwise marking an object, a material, a substance, and / or a surface with a composition or formulation of GROVE particles, and (b) detecting, observing, or measuring a change in optical properties as a function of applying a force. In embodiments, tagging or otherwise marking further comprises arranging, spraying, gluing, printing, and / or weaving the GROVE particles into the shape of characters comprising leters, numerical digits, and / or symbols.

[0070] In embodiments, the method of authenticating an object using a gravity-responsive optically- variable encapsulated (GROVE) particles comprises providing an object comprising GROVE particles, or comprising a composition of GROVE particles, wherein the object has an initial optical state, applying a force to the object and / or the GROVE particles, to cause a movement in the GROVE particles which elicits the object to present a change in one or more optical properties from the initial optical state, and detecting the change in the one or more optical properties as a function of the application of the force.

[0071] In embodiments, the GROVE particles are in a formulation, wherein the formulation comprises a fluid, suspension, ink, liquid film, adhesive, and / or material thereof; a foil, film, thin plastic, paper, and / or material thereof; or a fiber, thread, yarn, twine, and / or material thereof.

[0072] In embodiments, the method further comprises tagging, applying, arranging, spraying, gluing, and / or weaving the GROVE particles onto the object, optionally into the shape of characters comprising letters, numerical digits, symbols, and / or images.

[0073] In embodiments, authentication comprises object including paper, plastic, glass, metal, fabric, wood, a window, documentation, an electronic device, a computer chip, construction materials, human or animal tissue or skin, leather, luxury goods, high-value goods, hardware, computer hardware, and / or mobile phones. In embodiments, the object comprises paper currency, bank notes, checks, and / or money orders. In embodiments, the object comprises documentation, tax stamps, passports, identification, government-issued documents and permits, and driver’s license.

[0074] In embodiments, the object comprises a surface that has one or more regions that are substantially planar, non-planar, convex, concave, or without a well-defined shape. In embodiments, the GROVE particles and / or GROVE particle film are located on an interior surface of the object and / or on an exterior surface of the object.

[0075] In embodiments, the force applied comprises one or more of a mechanical force (shaking, agitation, jerking, tilting), gravity (reorienting the position relative to gravity), acoustic force (sound), magnetic force (magnetic field / flux), and an electrical field. In embodiments, applying the force comprises moving the object relative to the direction of gravity and / or applying a magnetic field. In embodiments, the force comprises directed a sound toward the GROVE particles.

[0076] In embodiments, the change in the optical property comprises a change in one or more color in the visible electromagnetic (EM) spectrum comprising an absorption, emission, extinction, reflection, scattering, and / or interference properties at a wavelength, optionally from about 350 nm to about 800 nm. In embodiments, the one or more color comprises one or more of white, black, red, orange, yellow, green, blue, indigo, violet, or a color shade or hue therebetween.

[0077] In embodiments, the shape of the characters is observable as a function of applying a force. In embodiments, the force comprises one or more of gravity, a mechanical force, an acoustic force, a magnetic force, and an electrical field. In embodiments the GROVE particles are arranged in one or more patterns, optionally comprising one or more shape, symbol, letter, number, picture, image, or message, further optionally from one or more of ASCII, English, Latin, Japanese, Chinese, Korean, Unicode, Unicode Transformation Format - 8 bit (UTF-8), UTF-16, UTF-32, ISO-8859, EBCDIC, Shift JIS, GB2312, GB18030, Big 5, KO18, Coptic, Greek, Cyrillic, Armenian, Arabic, Hebrew, Syriac, Mandaic, Brahmic, Georgian,Mandarin, Cantonese, Bengali, African, Mongolian, CJK, and / or any other known character set. In embodiments, the change in the optical property that is detected is substantially in the pattern of the particles.

[0078] In embodiments, one or more of the colors associated with the GROVE particles and / or GROVE film substantially corresponds with a color of the object to be authenticated.

[0079] In embodiments, the change in optical property is detectable by human vision, and / or wherein the change in optical property is not detectable by human vision. In embodiments, the change in optical property comprises one or more covert features. In embodiments, the one or more covert features comprises a change in optical property and / or a detectable signal as a function of the application of a force, optionally wherein the one or more covert features are not detectable by human vision.

[0080] In embodiments, detecting the change in the optical property comprises using one or more of a camera, spectrometer, filter, window, grating, beam splitter, polarizer, collimator, birefringent element, prism, bandpass filter, aperture, or lens to detect an optical signal emanating from the object. In embodiments, the detecting comprises measuring, observing, and / or registering an optical signal generated by the GROVE particles via one or more of an radio frequency (RF) reader, barcode scanner, human vision, and camera.

[0081] In embodiments, the detecting is performed as a function of the movement and as a function of time (e.g., were an optical signal / function as a function of time is observable from the optical change in response to a stimuli).

[0082] In embodiments, authenticating further comprising comparing the change in the one or more optical properties to a standard signal, wherein the comparison to the standard signal verifies the authenticity of the object.

[0083] In aspects, described herein is an overt authentication feature comprising one or more GROVE particles.

[0084] In aspects, described herein is a photonic device incorporating one or more GROVE particles.

[0085] In aspects, described herein is a microlens incorporating one or more GROVE particles.

[0086] In aspects, described herein is a gravity-responsive optically-variable encapsulated (GROVE) particle, wherein the GROVE particle is as substantially shown in any one of Figs. 1, 2A-2E, 4A-4L, 5A-5F, 6A-6G, 7A-7F, 20A-20G, 22A-22F, 24A-24D, 27A-27E, 28A-28E, 29A-29E, 30A-30B, 33A-33F, 34A-34G, 37, 38, 39, 40A-40D, 41A-41B, 42A-42D, 43A-43C, 44A-44C.DESCRIPTION OF THE DRAWINGS

[0087] Fig. 1 depicts an illustrative, non-limiting diagrammatic side-view representation of an exemplary gravity responsive optically variable encapsulated (GROVE) particle 100, comprising a core particle 102 in a yolk configuration within a transparent encapsulating outer shell 108. The core particle 102 comprises a less dense optically active first material 104 with an associated color (denoted by the white in the top half of the particle), and a denser optically active second material 106 with an associated color (denoted by the crosshatch pattern in the bottom half of the particle).

[0088] Figs. 2A-2E depict illustrative, non-limiting diagrammatic side-view representations of an exemplary GROVE particle according to embodiments of the present disclosure. The arrow pointing downward points toward the center of the earth, the direction of the force of gravity. Fig. 2A depicts a GROVE particle at equilibrium, with the heavier part of the core particle (in cross-hatch) resting at the lowest point within the encapsulating shell. Figs. 2B-2E depict a non-limiting variety of non-equilibrium configurations of GROVE particles, where in each the heavier part of the core particle is not at the lowest energy position within the shell.

[0089] Fig. 3 depicts an illustrative, non-limiting diagrammatic side view of the operation of a collection of GROVE particles arrayed on a surface. Initially, a collection of GROVE particles on a substrate is at equilibrium, with the heavier part of the core particles (denoted in cross-hatch) at the lowest possible points in their respective shells. An observer looking at the particles from above will see the color associated with the top part of the particle (white in the illustration). After a stimulus is applied, the GROVE particles are no longer at equilibrium, with the cores occupying a subset of all possible positions / orientations within the shell. Now the observer looking from above sees a mixture of the top and bottom colors (shown as a mixture of white and cross-hatch). In the third panel, the force of gravity has caused the core particles to return to their equilibrium position, and the observer again sees the top color (depicted as white).

[0090] Figs. 4A-4L depict a series of illustrative, non-limiting diagrammatic side-view representations of exemplary GROVE particles in equilibrium orientations.

[0091] Figs. 5A-5F depict a series of illustrative, non-limiting diagrammatic side-view representations of exemplary GROVE particles in equilibrium orientations.

[0092] Figs. 6A-6G depict a series of illustrative, non-limiting diagrammatic side-view representations of exemplary GROVE particles in equilibrium orientations. In Fig. 6A is shown a GROVE particle substantiallysimilar to that as shown in Fig. 1, in which the associated colors correspond to the densities of material such that the top hemisphere of the core particle is one color (depicted as white), and the bottom hemisphere is another color (depicted by cross-hatch). In Fig. 6B, the mass distribution of the particle is such that at equilibrium, one side hemisphere of the particle is one color, and the other side hemisphere is a different color. In Fig. 6C, the mass distribution of the particle is such that at equilibrium, the two hemispheres of color are tilted with respect to both the horizontal and vertical directions. In Figs. 6D-G, one or more higher-mass particles or regions of higher mass (denoted by black filled circles) are incorporated to influence the mass distribution.

[0093] Figs. 7A-7F depict a series of illustrative, non-limiting diagrammatic side-view representations of exemplary GROVE particles in equilibrium orientations. In Fig. 7A is shown a GROVE particle substantially similar to that as shown in Fig. 1. In Fig. 7B the core particle is coated. In Fig. 7C the GROVE particle additionally encapsulates a liquid, and / or solid material within the interior volume of the shell. In Fig. 7D the interior surface of the shell is coated or functionalized. In Fig. 7E additional particle(s) smaller in size than the core particle are present within the shell. In Fig. 7F additional particle(s) larger in size than the core particle (shown in gray) are present within the shell.

[0094] Figs. 8A-8H depict a series of illustrative, non-limiting diagrammatic side-view or tilted-view representations of assemblies of GROVE particles. Figs. 8A-8B show particle assemblies suspended in fluid solutions. Figs. 8C, 8F, and 8G show particle assemblies on surfaces. Figs. 8D, 8E, and 8H show particle assemblies in films, sandwiched between a top and bottom substrate.

[0095] Figs. 9A-9D depict a series of illustrative, non-limiting diagrammatic side-view representations of assemblies of GROVE particles. The core particle(s) comprise a lighter-colored, denser portion (e.g., shown in gray), and a small amount of a darker-colored, less dense portion (e.g., shown in black). Fig. 9A shows the particles on a substrate in the equilibrium position. Fig. 9B shows the particles on a substrate at equilibrium, with the substrate being the same color as the lower portion of the core particle. Fig. 9C shows the particles on a substrate at equilibrium, with the substrate being the same color as the upper portion of the particles. Fig. 9D shows the particles on a tilted substrate.

[0096] Fig. 10 depicts an illustrative, non-limiting diagrammatic representation of how GROVE particles are used to control the transmission of light. (For clarity, the outer shells of the GROVE particles are not shown). In the upper panel, the GROVE particles comprise a portion (e.g., shown as the cross-hatched bottom hemisphere of the particles) that is not transmissive to light, which are all oriented with thishemisphere facing downward, such that 50% of light impinging from the left onto the particles is transmitted. In the lower panel, the particles have been rotated 90° clockwise (e.g., via the application of a force) such that 0% of the incident light from the left is transmitted.

[0097] Figs. 11 A-11 C depict illustrative, non-limiting diagrammatic tilted representations of assemblies of GROVE particles that respond to acoustic waves. In each panel is shown a zoomed-in magnification of the assemblies of GROVE particles and their appearance after exposure to acoustic force (e.g., sound) at different stages. (For purposes of clarity, the outer shells of the GROVE particles are not shown). Fig. 11 A shows an assembly of the GROVE particles substantially similar to that of Fig. 1 (e.g., the top color shown as white, and the bottom color shown as black) applied to a square patch on a substrate, at equilibrium. Without sound, while sitting horizontally on a surface, the square patch appears white in color. In Fig. 11 B, the assembly is exposed to an acoustic force (sound), emanating from a nearby mobile telephone. As a consequence, the particles adopt non-equilibrium positions and the square patch appears to change colors to gray (e.g., a mixture of the top and bottom colors of the particles). In Fig. 11 C, the sound is removed from proximity to the particles, and the particles return to their equilibrium orientation and thus their initial color state.

[0098] Figs. 12A-12E depict illustrative, non-limiting diagrammatic representations of arrays of GROVE particles used with one or more stimuli to generate digital images. (For purposes of clarity, the shells of the GROVE particles have been omitted). Fig. 12A shows a substrate, with a grid pattern shown to facilitate location of position. Fig. 12B shows the substrate onto which an array of the GROVE particles substantially similarto that of Fig. 1 were deposited in the shape of the capital letter “I ”, with the particles in their equilibrium configuration (e.g., dark, denser hemisphere facing down). Fig. 12C shows the illustration of Fig. 12B, with the remaining area filled with particles of the same shape as the GROVE particles, but with both hemispheres of the particle having the same color as the less dense material for the particles in Fig. 12B (e.g., shown as entirely white). Fig 12D shows the illustration of Fig. 12C after applying a stimulus that selectively affects the GROVE particles, causing them to adopt non-equilibrium configurations. Fig. 12E shows the illustration of Fig. 12D after the stimulus ceases or is removed and the GROVE particles have returned to equilibrium.

[0099] Figs. 13A-13E depict illustrative, non-limiting diagrammatic representations of arrays of GROVE particles used with one or more stimuli to generate digital images. (For clarity, the shells of the GROVE particles have been omitted). Fig. 13A shows a substrate, with a grid pattern shown to facilitate location of position. Fig. 13B shows the substrate onto which an array of the GROVE particles substantially similar tothat of Fig. 1 were deposited in the shape of the letter “I”, with the particles in their equilibrium configuration (e.g., the darker, denser hemisphere facing down). Fig. 13C shows the illustration of Fig. 13B, with the remaining area filled with GROVE particles that have the same top color (shown as white) as the “I” particles in Fig. 13B, but with the bottom hemispheres of the particles having a different density as the “I” particles in Fig. 13B (shown as gray). Fig 13D shows the illustration of Fig. 13C after a stimulus that selectively affects the “I” GROVE particles, causing them to adopt non-equilibrium configurations. Fig. 13E shows the illustration of Fig. 13D after the stimulated GROVE particles have returned to equilibrium.

[0100] Figs. 14A-14E depict illustrative, non-limiting diagrammatic representations of arrays of GROVE particles used with one or more stimuli to generate digital images. (For clarity, the shells of the GROVE particles have been omitted). Fig. 14A shows a substrate, with a grid pattern shown to facilitate location of position. Fig. 14B shows the substrate onto which an array of the GROVE particles substantially similar to that of Fig. 1 were deposited in the shape of the letter T, with the particles in their equilibrium configuration (e.g., the darker, denser hemisphere facing down). Fig. 14C shows the illustration of Fig. 14B, with the remaining area filled with GROVE particles that have the same top color (shown as white) as the “I” particles in Fig. 14B, but with the bottom hemispheres of the particles having a different density as the “I” particles in Fig. 14B (shown as gray). Fig 14D shows the illustration of Fig. 14C after a stimulus that selectively affects the ‘non-T” (i.e. white top / gray bottom) GROVE particles, causing them to adopt non-equilibrium configurations. Fig. 14E shows the illustration of Fig. 14D after the stimulated GROVE particles have returned to equilibrium.

[0101] Figs. 15A-15E depict illustrative, non-limiting diagrammatic representations of arrays of GROVE particles used with one or more stimuli to generate digital images. (For clarity, the shells of the GROVE particles have been omitted). Fig. 15A shows a substrate, with a grid pattern shown to facilitate location of position. Fig. 15B shows the substrate onto which an array of the GROVE particles substantially similar to that of Fig. 1 were deposited in the shape of the letter T, with the particles in their equilibrium configuration (e.g., the darker, denser hemisphere facing down). Fig. 15C shows the illustration of Fig. 15B, with the remaining area filled with GROVE particles that have the same top color (shown as white) as the “I” particles in Fig. 15B, but with the bottom hemispheres of the particles having a different color as the “I” particles in Fig. 15B (shown as gray). Fig 15D shows the illustration of Fig. 15C after a stimulus that affects both types of GROVE particles, causing them to adopt non-equilibrium configurations. Fig. 15E shows the illustration of Fig. 15D after the stimulated GROVE particles have returned to equilibrium.

[0102] Figs. 16A-16B illustrate the effect of gravity on core particles having a 1.55 mm diameter polystyrene spheres to which one coat of silver (Ag) paint was applied to one hemisphere. In Fig. 16A, a pair of tweezers were used to roll the particle into its non-equilibrium orientation, with the denser Ag coated hemisphere pointing up. In Fig. 16B, the tweezers are released, the sphere rolled to the equilibrium configuration, with the Ag side down.

[0103] Figs. 17A-17D depict images of the silver (Ag)-painted particles of Fig. 16A-16B confined in plastic grids. Fig. 17A shows two Ag-paint-weighted particles in a 2 mm x 4 mm-sized grid hole after being agitated by moving the grid. Fig. 17B show the particles and grid of Fig. 17A after the particles have reoriented to reach gravitational equilibrium. Fig. 17C depicts an image of the particles of Fig. 16A-16B with each particle in a separate 2 mm x 4 mm-sized grid hole, after agitation by moving the grid. Fig. 17D show the particles and grid of Fig. 17C after the particles have reoriented to reach gravitational equilibrium.

[0104] Figs. 18A-18D show images of the silver (Ag)-painted particles of Fig. 16A-16B confined in plastic grids. Fig. 18A shows two Ag-paint-weighted particles in a 4 mm x 4 mm-sized grid hole after being agitated by moving the grid. Fig. 18B shows the particles and grid of Fig. 18A after the particles have reoriented to reach gravitational equilibrium. Fig. 18C shows an image of the particles of Fig. 16A-16B with each particle in a separate 4 mm x 4 mm -sized grid hole, after agitation by moving the grid. Fig. 18D show the particles and grid of Fig. 18C after the particles have reoriented to reach gravitational equilibrium.

[0105] Figs. 19A-19D show photographs of a Petri dish containing three different types of particles before (Fig. 19A) and after (Fig. 19B) application of a 220 Hz tone for 3 seconds, illustrating particle movement, as indicated by the change in position of the particles over the grid. Figs. 19C-19D show closeup images of the same.

[0106] Figs. 20A-20G depict illustrative, non-limiting diagrammatic side-view representations of synthetic routes to GROVE particles. Fig. 20A shows a Janus particle. Fig. 20B shows a coated Janus particle. Fig. 20C shows an encapsulated yolk-shell particle with a porous shell. Fig. 20D shows an encapsulated Janus particle in a yolk-shell configuration. Fig. 20E shows an encapsulated, coated Janus particle in a yolk-shell configuration. Fig. 20F shows a Janus particle encapsulated in a porous shell, in a yolk-shell configuration. Fig. 20G shows a coated Janus particle encapsulated in a porous shell, in a yolkshell configuration.

[0107] Figs. 21A-21 B depict images of Janus particles as core particles. Fig. 21 A depicts an image reproduced from Fig. 3a of Nisisako ef a / , “Synthesis of Monodisperse Bicolored Janus Particles withElectrical Anisotropy Using a Microfluidic Co-Flow System,” Adv. Mater., 2006, Vol. 18, 2006: pp. 1152-56. Fig. 21 B illustrates a non-limiting diagrammatic representation of the particles in Fig. 21 A.

[0108] Figs. 22A-22F depict illustrative, non-limiting diagrammatic side-view representations of GROVE particles.

[0109] Figs. 23A-23E depicts a non-limiting diagrammatic representation of a workflow for generating a hollow yolk-shell type GROVE particle including the steps of: A) producing a silica core, B) coating the silica core with polystyrene (PSt) to form a polystyrene layer around the silica core (e.g., a dissolution layer); C) forming a silica (SiO2) shell around the PSt layer; D) calcination at high temperature (e.g., at 500°C for 4 hr.) to create a void space between the silica shell and core; and E) etching with NH3.

[0110] Figs. 24A-24D depict illustrative, non-limiting diagrammatic side-view representations of an exemplary GROVE particle according to embodiments of the present discourse. Fig. 24A depicts a GROVE particle at equilibrium, with the lighter part of the core particle (in black) containing a single air pocket (represented by the white ellipse), and with the heavier part of the core particle (in crosshatch) resting at the lowest point within the encapsulating shell. Fig. 24B depicts a GROVE particle at equilibrium, with the lighter part of the core particle (in black) containing multiple air pockets (represented by the white ellipses), and with the heavier part of the core particle (in crosshatch) resting at the lowest point within the encapsulating shell. Fig. 24C depicts a representative GROVE particle at equilibrium, where the lighter top half of the particle contains an air pocket (represented by the white ellipse), with one color pointing left (represented by black), and the other color pointing right (in crosshatch). Fig. 24D depicts a representative GROVE particle at equilibrium, where the distribution of mass causes the particle to rest neither horizontally (as in Fig. 24A) nor vertically (as in Fig. 24C) with respect to the two colors).

[0111] Figs. 25A-25B depict illustrative, non-limiting diagrammatic side-view representations of an exemplary GROVE particle according to embodiments of the present discourse. (For clarity, the outer shells of the GROVE particles are not shown). Fig. 25A depicts the core of a GROVE particle comprising two parts, where one part is a spherical particle (in light gray), and the second part (in dark gray) is one or more materials situated on the top hemisphere of the particle. Fig. 25B depicts the core of a GROVE particle comprising two parts, where one part is a spherical particle (in light gray), and the second part (in dark gray) is one or more materials situated on the bottom hemisphere of the particle.

[0112] Figs. 26A-26B depict illustrative, non-limiting diagrammatic side views of an assembly of GROVE particles on a substrate. In Fig. 26A, GROVE particles are (depicted at equilibrium) in a randomarrangement, interspersed within a carrier fluid (depicted as black wavy lines and gray-colored substance). Fig. 26B depicts the particles after the carrier fluid has been subjected to one or more of high temperature, high pressure, high light intensity, or other method used to permanently affix a pigment-containing ink to a substrate.

[0113] Figs. 27A-27E depict a series of illustrative, non-limiting diagrammatic side views of GROVE particles with two encapsulating shells (the inner of which is depicted in gray and the outer of which is depicted in black). Fig. 27A depicts a GROVE particle at equilibrium with two encapsulating shells, both of which are spherical. Fig. 27B depicts a GROVE particle at equilibrium with two encapsulating shells, where the inner shell (illustrated in gray) is spherical and conformal to the Janus particle, and the outer shell (illustrated in black) is non-spherical and non-conformal to the inner shell. Fig. 27C depicts a GROVE particle at equilibrium with two encapsulating shells, where the inner shell (illustrated in gray) is non-spherical and non-conformal to the Janus particle or the outer shell, and the outer shell (illustrated in black) is spherical. Fig. 27D depicts a GROVE particle at equilibrium with two encapsulating shells, where the inner shell (illustrated in gray) is non-spherical and non-conformal to the Janus particle, but is conformal to the outer shell (illustrated in black). Fig. 27E depicts a GROVE particle at equilibrium with two encapsulating shells, where the inner shell (illustrated in gray) is non-spherical and non-conformal with both the Janus particle and the outer shell (illustrated in black), which is also non-spherical.

[0114] Figs. 28A-28E depicts a series of illustrative, non-limiting diagrammatic side-view of compositions and processes used to make GROVE particles. Fig. 28A depicts a Janus particle. Fig. 28B depicts a Janus particle after encapsulation in a reversibly-swellable polymer shell (shown in gray). In Fig. 28C, the polymer coating of the particle of Fig. 28B is expanded. In Fig. 28D, a shell (illustrated in black) is grown around the expanded polymer shown in Fig. 28C. Fig. 28E depicts a GROVE particle that results from contraction of the polymer in the particle of Fig. 28D.

[0115] Figs. 29A-29E depict illustrative, non-limiting diagrammatic representations of encapsulated GROVE particles, where in addition to the GROVE particles themselves, a fluid (shown in gray) is contained within the encapsulated region. Fig. 29A depicts an encapsulated GROVE particle at equilibrium and an encapsulated fluid, where the density of the Janus particle is less than the density of the fluid. Fig. 29B depicts an encapsulated GROVE particle at equilibrium and an encapsulated fluid, where the density of the particle is equal to the density of the fluid. Fig. 29C depicts an encapsulated GROVE particle at equilibrium and an encapsulated fluid, where the density of the particle is higher than the density of the fluid. Fig. 29Ddepicts an encapsulated GROVE particle at equilibrium and an encapsulated fluid, where the Janus particle floats atop the fluid, and the fluid volume is small compared to the volume of the Janus particle. Fig. 29E depicts an encapsulated GROVE particle at equilibrium and an encapsulated fluid, where the Janus particle is immersed in the fluid, and the fluid volume is small compared to the volume of the Janus particle.

[0116] Figs. 30A-30B depict illustrative, non-limiting diagrammatic side-view representations of exemplary encapsulated GROVE particles in an equilibrium orientation, where the Janus particles comprise materials with a gradient in density. In Fig. 30A, the Janus particle comprises materials of three different densities (illustrated by the three different shades of gray), where the material depicted in the lightest gray color is lightest in density, the area illustrated in a medium gray has a heavier density than the lightest gray, and the area in darkest gray has the heaviest density. Fig. 30B depicts a GROVE particle where the Janus particle comprises materials that change in density gradually from lightest (shown in lightest gray) to heaviest (shown in darkest gray) over the particle.

[0117] Fig. 31 depicts an illustrative, non-limiting diagrammatic side view of a random arrangement of GROVE particles embedded within a thin film (illustrated in light gray). When the film is transparent, an observer looking at the film from the top will see the color associated with the darker-colored hemispheres of the Janus particle, while an observer looking at the film from the bottom will see the color associated with the lighter-colored hemispheres.

[0118] Figs. 32A-32F depict illustrative, nonlimiting diagrammatic side view representations of exemplary routes of micelle, nanoparticle, and / or surfactant-based synthesis of GROVE particles.

[0119] Figs. 33A-33F depict illustrative, nonlimiting diagrammatic side view representations of exemplary routes of synthesis involving dissolution to form GROVE particles.

[0120] Figs. 34A-34G depict illustrative, nonlimiting diagrammatic side view representations of a microfluidic apparatus used in synthesis of GROVE particles.

[0121] Figs. 35A-35C depict illustrative, nonlimiting diagrammatic side view representations of printed arrays of GROVE particles. (For purposes of clarity, the shells of the GROVE particles have been omitted). Fig. 35A shows a substrate. Fig. 35B shows a substrate onto which is printed a first type of GROVE particle. Fig. 35C shows the substrate of Fig. 35B onto which a second type of GROVE particle has been printed adjacent to the first type.

[0122] Figs. 36A-36F illustrative, non-limiting diagrammatic representations illustrative, non-limiting diagrammatic side view of the operation of a collection of two different types GROVE particles arrayed adjacently on a surface. (For purposes of clarity, the shells of the GROVE particles have been omitted). Initially, as shown in Fig. 36A, the two collections of GROVE particles on a substrate are at equilibrium, with the heavier parts of the core particles at the lowest possible points in their respective shells. An observer looking at the particles from above will see the color associated with the top part of the particles in each region. After an agitating force is applied, the GROVE particles are no longer at equilibrium, with the cores occupying a subset of all possible positions / orientations within the shell (Fig. 36C). Now the observer looking from above sees a mixture of the top and bottom colors (Fig. 36D) in accordance with the spatial positioning of the two types of GROVE particles. In Fig. 36E, the force of gravity has caused the core particles to return to their equilibrium position, and the observer again sees the top colors of the spatially arrayed types of GROVE particles (Fig. 36F).

[0123] Fig. 37 depicts an SEM image of “raspberry-shaped” particles comprising a polystyrene core with silica lobes on the polystyrene surface. Scale bar is 5 pm.

[0124] Figs. 38A-38B shows SEM images of 3 pm diameter methacrylate-functionalized silica spheres before (Fig. 38A) and after (Fig. 38B) coating with polystyrene. Scale bar is 5 pm.

[0125] Figs. 39A-39F show SEM images of 3 pm polystyrene spheres (Fig. 39A) and 5 pm polystyrene spheres (Fig. 39D) after initial silica lobe growth (Figs. 39B and 39E), and a silica growth filling the lobe interstices (Figs. 39C and 39F). Top scale bar is 3 pm; bottom scale bar is 5 pm.

[0126] Figs. 40A-40D show SEM images of polystyrene spheres (Fig. 40A) and polymethyl methacrylate spheres (Fig. 40C) before and after growth of a vinyl silica coating (Figs. 40B and 40D). Scale bar is 10 pm.

[0127] Figs. 41 A-41 B show SEM of polystyrene-silica-polystyrene core-shell-shell spheres (Fig. 41 A) and polystyrene-void-polystyrene yolk-shell spheres after silica removal (Fig. 41 B). Scale bar is 5 pm.

[0128] Figs. 42A-42D show SEM images of iron-capped silica particles coated with polystyrene and then with silica (Fig. 42A). Fig. 42B shows the corresponding particles after removal of the polystyrene coating. Fig. 42C is a close-up of the region highlighted by the white box in Fig. 42A. Fig. 42D is a close-up of the region highlighted by the white box in Fig. 42B. Scale bar is 5 pm.

[0129] Figs. 43A-43C show transmission optical microscopy images of polymethylmethacrylate polymer particles (Fig. 43A), after coating with a swellable methacrylic acid-based polymer (Fig. 43B), and after pH-induced swelling (Fig. 43C).

[0130] Figs. 44A-44C show transmission optical microscopy images of a methacrylate-based silica particles (Fig. 44A), after coating with a swellable methacrylic acid-based polymer (Fig. 44B), and after pH- induced swelling (Fig. 44C).DETAILED DESCRIPTIONGravity-Responsive Optically-Variable Encapsulated (GROVE) Particles and Compositions Thereof

[0131] The present disclosure provides, in part, gravity-responsive optically-variable encapsulated (GROVE) particles and compositions thereof. In embodiments, GROVE particles comprise (i) an inner particle (an optically active portion) contained within an encapsulant or outer shell, and (ii) possess optical properties which change over time in response to one or more stimuli. Examples of stimuli, in non-limiting embodiments, include mechanical agitation (e.g., shaking, tilting, jerking, rocking, etc.), gravity, temperature, magnetic field / flux, acoustic force (sound), electrical field, and pressure. In embodiments, the optical properties include, but are not limited to, absorption, scattering, transmission, refraction, reflectance, reflection, transmittance, dispersion, birefringence, polarization, color, hue, tint, albedo, turbidity, fluorescence, luminescence, phosphorescence, Raman scattering, and surface enhanced Raman scattering. In embodiments, GROVE particles are formulated into a composition (e.g., a fluid, ink, suspension, fiber, film, etc.) to be printed, sprayed, imbued, or otherwise applied to an object to confer the changing of optical properties in response to stimuli onto the object.

[0132] In embodiments, the GROVE particle comprises a yolk-shell particle, wherein the yolk-shell particle comprises at least two materials, each with a distinct density, at least two optically active agents disposed thereon, and a shell that is transparent to at least a portion of an electromagnetic spectrum between frequencies of about 10 nm to about 10 cm, and where the GROVE particle exhibits a change in an optical property as a function of exposure to a force.

[0133] For example, in embodiments, Fig. 1 provides a side-view representation of a GROVE particle. In embodiments, the particle 100 has an inner core particle 102, which comprises at least two materials with different optical properties, a first material 104 and a second material 106. In embodiment, the first material 104 is a less dense material with a first optical property, and the second material 106 is a denser materialwith a second optical property. In embodiments, within the inner or core particle 102, the density e.g., as defined as the mass per unit of volume) is anisotropic. In embodiments, the density of the material or materials comprising 104 and 106 differ. As shown in Fig. 1, in embodiments, the second material 106 has a greater density than the first material 104. As such, in its lowest-energy configuration, in embodiments, the core particle 102 is oriented such that the denser, second material 106 is at the lowest possible point within the outer shell 108. In embodiments, this configuration is referred to herein as the “equilibrium configuration” or “equilibrium position,” i.e., the position at which the gravitation potential energy of the core particle 102 is minimized (or at a local minima).

[0134] In embodiments, the particle 100 has an encapsulant or outer shell 108 that surrounds the inner core particle 102. For example, in embodiments, the GROVE particle of Fig. 1 has a transparent outer shell 108. 1 n embodiments, “transparent” refers to a property of at least a portion of the outer shell 108 comprising a material that is transparent to (e.g., allows transmission of) at least a portion of the electromagnetic spectrum between the x-ray / ultraviolet region (wavelengths >10 nm) and microwave / radio region (<10 cm). In embodiments, the shell is configured to allow observation of the change in optical property, for example, where the change is a change in color in the electromagnetic spectrum between about 300 nm and about 1200 nm (or in the visible spectrum, from about 380 nm to about 750 nm).

[0135] In embodiments, the outer shell (e.g., such as the outer shell 108 of the GROVE particle of Fig. 1) comprises a dimension (e.g., a thickness, diameter, or radius) of about 10 nm to about 1 mm, for example, of about or at least 10 nm, about or at least 20 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm (1 pm), about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at leastabout 300 m, about or at least about 400 pm, about or at least about 500 pm, or about or at least about 1000 pm (1 mm), including dimensions therebetween.

[0136] In embodiments, the core particle (e.g., such as the core particle 102 of the GROVE particle of Fig. 1) comprises a dimension (e.g., diameter or radius) of about 5 nm to about 1 mm, for example, about or at least 5 nm, about or at least about 15 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm (1 pm), about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 250 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, or about or at least about 1000 pm (1 mm), including dimensions therebetween.

[0137] In embodiments, a ratio of densities between a first material 104 (e.g., a less dense optical material) and a second material 106 (e.g., a denser optical material), for example with reference to the GROVE particle of Fig. 1, is about or at least about 1 :1.01, about or at least about 1 :1.05, about or at least about 1 :1.1 , about or at least about 1 :1.2, about or at least about 1:1.3, about or at least about 1 :1.4, about or at least about 1:1.5, about or at least about 1 :2, about or at least about 1 :3, about or at least about 1:4, about or at least about 1:5, about or at least about 1:6, about or at least about 1 :7, about or at least about 1 :8, about or at least about 1:9, about or at least about 1 :10 or more, including ratios therebetween. In embodiments, the materials (e.g., the first material 104 and second material 106) are distinct materials which comprise distinct optical properties and density. In embodiments, the materials (e.g., the first material 104 and second material 106) are substantially the same material which are coated with materials comprising distinct optical properties, which alter the density.

[0138] In embodiments, the first material 104, or the second material 106, or both the first material 104 and second material 106 comprise one or more of metals, metal oxides, metal nitrides, inorganic materials, silica, organic materials, organic polymers, inorganic polymers, biological polymers, synthetic polymers, and combinations thereof.

[0139] In embodiments, the first material 104, or the second material 106, or both the first material 104 and second material 106 comprise a single colorant, 2 colorants, 3 colorants, 4 colorants, 5 colorants, 6 colorants, 7 colorants, 8 colorants, 9 colorants, or 10 or more colorants. In embodiments, the terms “optically active agent” or “colorant” are used interchangeably and refer to a chemical entity that has an optical property, including absorbing, scattering (including Raman scattering), transmitting, refracting, reflecting, dispersing, polarizing, fluorescing, luminescing, and / or phosphorescing, any wavelength, or range of wavelengths, of radiation. In embodiments, wavelength, or range of wavelengths, of radiation are in the visible spectrum, i.e., from about 380 nm to about 800 nm in wavelength. In embodiments, an optical agent or colorant possesses a color, brightness, fluorescence, reflectance, etc., that can be detected by human vision. In embodiments, the at least one optically active agent or colorant possesses an extinction in the electromagnetic spectrum between the x-ray / ultraviolet region (wavelengths >10 nm) and microwave / radio region (<10 cm). In embodiments, the least one optically active agent or colorant has an extinction in the visible region of the electromagnetic spectrum, or a color of one or more of white, black, red, orange, yellow, green, blue, indigo, violet, and variations of hue, shade, and intensity therebetween.

[0140] In embodiments, the first material 104, or the second material 106, or both the first material 104 and the second material 106 comprise a dye, pigment, stain, fluorophore, metallic salt, and / or chromophore.

[0141] In embodiments, the one or more optically active agents herein comprise pigments commonly used in printing inks, including but not limited to Pigment Blue 15:3, Pigment Red 122, Pigment Violet 19, Pigment Yellow 12, 13, or 74), Pigment Black 7, Pigment White 6, Pigment Red 57:1. Pigment Orange 34 or 36, Pigment Green 7 - Phthalocyanine Green), Pigment Blue 15, Pigment Violet 23, Pigment Brown 23 or 25, Pigment Yellow 42, Pigment Brown 7, Pigment Red 101 , and Pigment Blue 29. In embodiments, the pigment comprises a pigment, e.g., such as Pigment Yellow 83 or Pigment Yellow 176, that is dispersible in an organic solvent.

[0142] In embodiments, the first material 104, or the second material 106, or both the first material 104 and the second material 106 comprise one or more dyes. In embodiments, the dye is an organic or inorganicdye. In embodiments, the dye comprises one or more of Rhodamine B, Congo Red, Crystal Violet, Methylene Blue, Acridine Orange, Nile Red, Malachite Green, Eosin Y, Cresol Red, Fluorescein, and Indigo.

[0143] In embodiments, the one or more colorant comprises a pigment. In embodiments, the pigment comprises a water-soluble pigment. In embodiments, the water-soluble pigment is one or more of anthocyanin, anthraquinone, carotenoid, violacein, melanin, pyocyanin, prodiginines, asperversin, benzoquinone, anthraquinone, and derivatives thereof.

[0144] In embodiments, the pigment comprises one or more of Titanium White (PW6), Zinc White (PW4), Carbon Black (PBk7), Mars Black (PBk11), Iron Oxide Red (PR101), Cadmium Red (PR108), Alizarin Crimson (PR83), Cadmium Orange (PO20), Cadmium Yellow (PY35), Lemon Yellow (PY3), Chromium Green Oxide (PG17), Phthalo Green (PG7), Ultramarine Blue (PB29), Cobalt Blue (PB28), Cerulean Blue (PB35), Prussian Blue (PB27), Burnt Sienna (PBr7), Raw Umber (PBr7), Raw Sienna (PBr7), and Yellow Ochre (PY43).

[0145] In embodiments, the pigment is an organic pigment. In embodiments, the pigment is an inorganic pigment.

[0146] In embodiments, the organic pigment or inorganic pigment comprises a white pigment. In embodiments, the white pigment is one or more of lead white (2PbCO3'Pb(OH)2), kaolin, silica (SiO2), titanium dioxide (TiC / rutile and anatase), zinc oxide (ZnO), zinc sulfide (ZnS), and / or lithopone (ZnS + BaSO4).

[0147] In embodiments, the organic pigment or inorganic pigment comprises a black pigment. In embodiments, black pigment is one or more of coal (charcoal), groutite (a-MnOOH), manganite (y-MnOOH), hausmannite (Mn3O4), carbon black, iron oxide black (Fe3O4), and / or spinel black (CuCr2O4).

[0148] In embodiments, wherein the organic pigment or inorganic pigment comprise a colored pigment.

[0149] In embodiments, the colored pigment comprises a yellow pigment. In embodiments, the yellow pigment comprises one or more of yellow ochre (a-FeOOH), auric pigment (AS2S3), lead ochre (PbO), lead tin yellow (Pb2SnO4, PbSn2SiO / ), Naples yellow (Pb(SbO3)2), zinc yellow (Zn2CrO4), Indian yellow (C19H16O10), iron oxide yellow (a-FeOOH), chromium titanium yellow ((Ti,Cr,Sb)O2), nickel titanium yellow ((Ti, Ni,Sb)O2), lead yellow (PbCrO4), cadmium yellow (CdS), bismuth yellow (BiVO4).

[0150] In embodiments, the colored pigment comprises a red pigment. In embodiments, the red pigment comprises one or more of red ocher (a-Fe2O3), Terra di Siena (a-Fe2O3), vermilion (HgS), lead red (Pb3O4),alizarin madder varnish, alizarin red (C14H8O4), iron oxide red (o-Fe2O3), molybdate red (Pb(Cr,S,Mo)O4), cadmium red (Cd(S,Se)).

[0151] In embodiments, the colored pigment comprises a green pigment. In embodiments, the green pigment comprises one or more of green earth (Fe silicates), Schweinfurt green (C4H6AS6CU4O16), chromium oxide green (C Os), chromium oxide hydrate green (CrOOH), cobalt green (CtoTiCh).

[0152] In embodiments, the colored pigment comprises a blue pigment. In embodiments, the blue pigment comprises one or more of lazurite (lapis lazuli), Egyptian blue (CaCuSi4O ), azurite (2CUCO3'CU(OH)2), malachite (CuCO3'Cu(OH)2), cobalt blue (COAI2O4), ultramarine blue (Na6AI6Si6O24(NaSn)), iron blue (K[FeiiiFe"(CN)6] xH2O).

[0153] In embodiments, the colored pigment comprises a brown pigment. In embodiments, the brown pigment comprises one or more of burnt umber (Fe2O3-xMnO2), brown ocher (a-Fe2O3 + Mn oxides), limonite (mixture of different Fe oxides).

[0154] In embodiments, the pigment is one or more of an oxide or oxide hydroxide pigment (TiC , ZnO, a-Fe2O3, a-FeOOH, y-Fe2O3, FesCU, CtoOs, CrOOH, PbO, PB3O4, MnsO4, -MnOOH, Sb2O3), a complex oxide pigment (COAI2O4, CuCr2O4, Co2TiO4, (Ti,Ni,Sb)O2, (Ti,Cr,Sb)O2), a carbonate hydroxide pigment (2PbCO3-Pb(OH)2, 2CUCO3-CU(OH)2, CUCO3-CU(OH)2), a sulfide / selenide pigment (ZnS, CdS, Cd(S,Se), CdSe, y-Ce2S3, HgS, AS2S3), a chromate / molybdate pigment (PbCrO4, Pb(Cr,S)O4, Pb(Cr,S,Mo)O4, ZnCrO4, BaCrO4, SrCrO4), a vanadate pigment (BiVCh, 4BiVO4'3Bi2MoOe), a stannate pigment (Pb2SnO4, PbSn2SiO / , Co2SnO4, CoSnOs), a phosphate pigment (Co3(PO4)2), an antimonate pigment (Pb(SbO3)2), an arsenate pigment (Cu(AsO3)2), an ultramarine pigment (NaeAl6Si6O24(NaSn)), a hexacyanidoferrate / hexacyanoferrate pigment (K[FelllFell(CN)6] xH2O (x = 14-16)), an oxonitride pigment (CaTaO2N, LaTaON2), an elemental-based pigment (C, Al, Cu, Cu / Zn, Au), a spinel-based pigment, and / or a rutile-based metal pigment.

[0155] In embodiments, the inorganic pigment is one or more of a “special optical material,” such as one or more of a transparent effect pigment, goniochromatic pigment, pearlescent pigment, metallic pigment, interference pigment, metallic effect pigment, fluorescent pigment, luminescent pigment, phosphorescent pigment, magnetic pigment, anticorrosive pigment, anisotropic material, and / or plasmonic material.

[0156] In embodiments, the metallic pigment comprises one or more of aluminum, bronze, and copper metallic pigment.

[0157] In embodiments, the pearlescent pigment comprises one or more of mica, titanium dioxide, and bismuth oxychloride.

[0158] In embodiments, the fluorescent pigment comprises one or more fluorescent dye and pigment comprising a fluorescent mineral.

[0159] In embodiments, the phosphorescent pigment comprises zinc sulfide and / or strontium aluminate.

[0160] In embodiments, the interference pigment comprises titanium dioxide-coated mica and / or aluminum oxide-coated mica.

[0161] In embodiments, the one or more colorants comprise an anisotropic particle. In embodiments, the anisotropic particle comprises a nanoparticle of the one or more metals, optionally comprising a nanorod of one or more of gold (Au), silver (Au), and aluminum (Al).

[0162] In embodiments, the one or more colorants comprises a plasmonic material. In embodiments, the plasmonic material comprises a pigment, particle, foil, and / or film. In embodiments, the film comprises a polymer-film loaded with noble metal nanoparticles.

[0163] In embodiments, the goniochromatic pigment comprises aluminum coated with magnesium fluoride embedded in chromium.

[0164] In embodiments, at least one of the at least two materials comprise a magnetic material and / or the GROVE particle responds to a magnetic force (e.g., the application of a magnetic stimuli, magnetic field, etc.). For example, in embodiments and in reference to Fig. 1, the first material 104, or the second material 106, or both the first material 104 and the second material 106 comprise a magnetic material and / or are coated with a magnetic material. In embodiments, the magnetic material is ferromagnetic, ferrimagnetic, antiferromagnetic, diamagnetic, paramagnetic, superparamagnetic, and / or antiferromagnetic. In embodiments, the magnetic material is organic, carbon-based, and / or biomolecule-based comprising one or more of tetracyanoethylene (TCNE) salts, [Fe(C5Me5)2]+[TCNE]«-, LifTCNE], [MnllTPP][TCNE]« (TPP = tetraphenylporphyrin), [Fell(TCNE)(NCMe)2][FelllCI4], Mnll(TCNE)l(OH2), Mnll(TCNE)[C4(CN)8]1 / 2, Fe(TCNE)[C4(CN)8]1 / 2, Mnll(TCNE)3 / 2(l3)1 / 2, VII|TCNE]x (x « 2), C7H5CIN3Se4, magnetic organic polymers, and / or polymer-bonded magnets. In embodiments, the magnetic material comprises iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), manganese (Mn), chromium (Cr), samarium (Sm), alloys or oxides thereof; alloys, intermetallic, and / or oxides of Fe, Co, Ni, Zn, Mn, Sm; oxides are of iron, Fe2O3, FeO, and / or Fe3O4; ferrite material and / or doped materials of Co, Ni, Zn, and / or Mn:FexOy, and / or magnetite.

[0165] In embodiments, GROVE particles are composed of iron (Fe) which confers magnetic responsiveness to GROVE particles (e.g., changing from color A to color B by movement), and also confers desired mass properties, for example, making the particle return to equilibrium (color B to color A) by gravity. In embodiments, iron, nickel, or any other magnetic material with a mass greater than the average mass of the core (Janus particle core) can be used for this purpose. In embodiments, magnetic materials are useful for conferring desired magnetic property and density.

[0166] In embodiments, the at least two materials, the optically active agents, and / or the outer shell comprise a polymeric material. For example, in embodiments and in reference to Fig. 1, the first material 104, or the second material 106, or both the first material 104 and the second material 106 contain polymeric materials. In embodiments, the polymeric material comprises one or more of polymers including plastics, acrylic resin, styrene acrylic copolymer, vinyl acetate ethylene copolymer, polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, polyurethane, epoxy resin, alkyd resin, cellulose acetate, silicone resin, a fluoropolymer resin, chlorinated rubber, a copolymer derived from maleic anhydride, ethylene vinyl acetate, polyethylene, polypropylene, polyamides (nylons), polyester resins, polybutadienes, thermally responsive polymers, latex, hydrocarbons, crude oil derivatives and / or petroleum derivatives, poloxamers, styrene-butadiene block copolymers, polymethylmethacrylate, polybutylmethacrylate, poly(tert-butyl acrylate)-poly(3- (triethoxysilyl)propyl methacrylate) (PtBA-PTPM), polystyrene latex polymer, carboxylated latex polymer, aminated latex polymer, colored polystyrene polymer (dye-infused and / or pigment-infused), colored polystyrene-based carboxylated latex polymer (dye-infused and / or pigment-infused), fluorescent polystyrene-based polymers, fluorescent polystyrene-based carboxylated latex polymers, fluorescent aminated polystyrene-based polymer, surfactant-free polystyrene, carboxylated surfactant-free polymer, polymethyl methacrylate (PMMA) latex polymer, and / or divinylbenzene-crosslinked polystyrene latex, plasticized polyvinyl chloride, plasticized nylon, plasticized polyethylene terephthalate, polyacrylonitrile, polychlorotrifluoroethylene, poly-4, 4'-isopropylidenediphenylene carbonate, polyethylene vinyl ester, polyvinyl chloride-diethyl fumarate, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers, acrylonitrile butadiene styrene, epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer, cyclic olefin polymer, poly dimethyl siloxane, poly ether ester ketone, polyetherimide, and combinations thereof.

[0167] In embodiments, the polymeric material of either the optically active agents or the outer shells are functionalized with pendant functional groups. In embodiments, the pendant functional groups comprise alcohols, ethers, aldehydes, ketones, carboxylates, amides, esters, amines, alkyl amines, dialkyl amines,cyanides, isocyanides, thiethers, sulfhydryls, or thioesters. In embodiments, GROVE particles are functionalized to confer the desired surface chemical properties to the outer shell and / or core particle. In embodiments, GROVE particles (e.g., silica shell and / or core) are functionalized to be more hydrophilic or hydrophobic, for example by treatment with alkyl groups, hydrocarbons (e.g., C12), PEG-silanes, etc., for example as described in Bjbrkegren et al., “Hydrophilic and hydrophobic modifications of colloidal silica particles for Pickering emulsions,” Journal of Colloid and Interface Science, Volume 487 (2017): pp. 250-257, the entire contents of which are incorporated herein by reference. In embodiments, the outer shell of the GROVE particle is functionalized to make the particles more hydrophobic. In embodiments, the outer shell of the GROVE particle is functionalized to make the particles more hydrophilic.

[0168] In embodiments, the at least two materials, the optically active agents, and / or the outer shell comprise a naturally occurring polymers and / or biological polymers. For example, in embodiments and in reference to Fig. 1 , the first material 104, or the second material 106, or both the first material 104 and the second material 106 contain naturally occurring polymers and / or biological polymers. In embodiments, the one or more biological polymers comprise nucleic acid (DNA, RNA), amino acid (peptide, protein), polysaccharide, and / or lipid.

[0169] In embodiments, the outer shell comprises a single material or more than one material. For example, in embodiments and in reference to Fig. 1, the outer shell 108 includes a single material, or two materials, or 3 materials, or 4 materials, or 5 or more materials. In embodiments, difference sections of the surface area of the outer shell comprise different materials, and / or different layers of the outer shell comprise different materials. For example, in embodiments, the outer shell includes at least a portion which is opaque and sections that are transparent ( / .e., composed of differing materials), which obscure viewing angles for viewing optical property changes. In embodiments, the outer shell 108 comprises a single layer, or two layers, or 3 layers, or 4 layers, or 5 or more layers.

[0170] In embodiments, the at least one layer of the outer shell comprises a single, uniform thickness and / or varying thicknesses. In embodiments, the at least one layer of the outer shell comprises a thickness of about or at least about 1 nm, about or at least about 5 nm, about or at least about 10 nm, about or at least about 15 nm, about or at least about 20 nm, about or at least about 25 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 100 nm, about or at least about 200 nm, about or at least about 300 nm, about or at least about 400 nm, about or at least about 500 nm, about or at least about 600 nm, about or at least about 700 nm, about or at least about 800 nm,about or at least about 900 nm, about or at least about 1 m, about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 10 pm, about or at least about 15 pm, about or at least about 20 pm, about or at least about 25 pm, about or at least about 30 pm, about or at least about 35 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, about or at least about 600 pm, about or at least about 700 pm, about or at least about 800 pm, about or at least about 900 pm, or about or at least about 1000 pm (1 mm), including thicknesses therebetween.

[0171] In embodiments, the outer shell comprises layer-by-layer assembled materials. In embodiments, the outer shell is formed by etching and / or the use of swellable materials. In embodiments, swellable materials include polymers which increase or decrease in volume as a function of changing conditions, such as pH, temperature, metal salt concentration, etc. For example, in embodiments, swellable polymers can increase in volume or decrease in volume by decreasing pH or increasing pH, increase temperature or decreasing temperature, or by increasing metal ion (metal salt) concentration or decreasing metal ion concentration. In embodiments, and in reference to Figs. 28A-28E, swellable polymers are used to create an encapsulated JP-based GROVE particle. In embodiments, this process does not involve removal of sacrificial layer. For example, in embodiments, a swellable material is applied to the core particle (e.g., as shown in Figs. 28B-28C), the outer shell is encapsulated around the swellable material (e.g., as shown in Fig. 28D), and then changing one or more of the pH, temperature, and / or metal ion concentrations controls the extent of swelling / shrinking to generate a void space between the core particle and shell (e.g., as shown in Fig. 28E and / or as demonstrated in Figs. 43A-43C and 44A-44C).

[0172] In embodiments, the outer shell is optically transparent from the x-ray and / or ultraviolet (UV) region of radiation (wavelengths >10 nm) to the microwave / radio region (<10 cm). In embodiments, for example in reference to Fig. 1, the at least one layer of outer shell 108 comprises at least a portion that transmits electromagnetic radiation in the ultraviolet, visible, or near-IR regions of the spectrum (between 300-1200 nm). In embodiments, layers of the outer shell are used to filter or select for specific wavelengths or ranges of wavelengths of radiation. In embodiments, the shell transmits a percentage of the incident electromagnetic radiation through the at least one layer of outer shell of about 100%, or about 99%, or about 98%, or about 97%, or about 96%, or about 95%, or about 94%, or about 93%, or about 92%, or about 91 %, or about 90%, or about 85%, or about 80%, or about 75%, or about 70%, or about 65%, or about 60%, or about 55%, or about 50%, or about 40%, or about 30%, or about 20%, or about 10%, or about 5%, or about4%, or about 3%, or about 2%, or about 1 %, or about 0.5%, or about 0.4%, or about 0.3%, or about 0.2%, or about 0.1 %, or about 0.05%, or about 0.04%, or about 0.03%, or about 0.02%, or about 0.01%, or 0.005%, or about 0.001%, relative to the intensity or amount of incident radiation that impinges on the material of the outer shell.

[0173] In embodiments, the outer shell contains polymeric materials. In embodiments, the polymers comprise one or more of plastics, acrylic resin, styrene acrylic copolymer, vinyl acetate ethylene copolymer, polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, polyurethane, epoxy resin, alkyd resin, cellulose acetate, silicone resin, a fluoropolymer resin, chlorinated rubber, a copolymer derived from maleic anhydride, ethylene vinyl acetate, polyethylene, polypropylene, polyamides (nylons), polyester resins, polybutadienes, thermally responsive polymers, latex, hydrocarbons, crude oil derivatives and / or petroleum derivatives, poloxamers, styrene-butadiene block copolymers, polymethylmethacrylate, polybutylmethacrylate, polyftert- butyl acrylate)-poly(3-(triethoxysilyl)propyl methacrylate) (PtBA-PTPM), polystyrene latex polymer, carboxylated latex polymer, aminated latex polymer, colored polystyrene polymer (dye-infused and / or pigment-infused), colored polystyrene-based carboxylated latex polymer (dye-infused and / or pigment- infused), fluorescent polystyrene-based polymers, fluorescent polystyrene-based carboxylated latex polymers, fluorescent aminated polystyrene-based polymer, surfactant-free polystyrene, carboxylated surfactant-free polymer, polymethyl methacrylate (PMMA) latex polymer, and / or divinylbenzene-crosslinked polystyrene latex, plasticized polyvinyl chloride, plasticized nylon, plasticized polyethylene terephthalate, polyacrylonitrile, polychlorotrifluoroethylene, poly-4, 4'-isopropylidenediphenylene carbonate, polyethylene vinyl ester, polyvinyl chloride-diethyl fumarate, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers, acrylonitrile butadiene styrene, epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer, cyclic olefin polymer, poly dimethyl siloxane, poly ether ester ketone, polyetherimide, and combinations thereof.

[0174] In embodiments, the outer shell includes naturally occurring polymers and / or biological polymers. In embodiments, the one or more biological polymers comprise nucleic acid (DNA, RNA), amino acid (peptide, protein), polysaccharide, and / or lipid.

[0175] In embodiments, the outer shell includes one or more inorganic materials. In embodiments, the inorganic materials comprise one or more of alumina, silica, titania, silicon nitride, zirconia, copper oxide, iron oxide, cobalt oxide, silver, gold, aluminum, copper, tin oxide, nickel oxide, lead oxide, glass, quartz, sapphire, inorganic glasses, diamond, diamond-like materials, zinc oxide, and manganese oxide.

[0176] In embodiments, the GROVE particle is also referred to as an encapsulated particle, encapsulated yolk-shell particle, egg-yolk-shell particle, core-shell particle, rattle or nanorattle ( / .e., when on the nm scale), among others. In embodiments, a geometric element of the GROVE particle, for example in reference to Fig. 1, is that the inner core particle 102 is spatially confined within the interior volume of the outer shell 108. In embodiment, the inner core particle is described, for example, in Kuk S, et al., “Rattle- Structured Upconversion Nanoparticles for Near-IR-lnduced Suppression of Alzheimer's B-Amyloid Aggregation,” Small, Vol. 13, No. 11 , 2017: pp. 1-8; and Zhang et al., “Mesoporous Multifunctional Upconversion Luminescent and Magnetic “Nanorattle” Materials for Targeted Chemotherapy,” Nano Let, Vol. 12, 2012: 61-67, both of which are hereby incorporated by reference in their entirety.

[0177] In embodiments, the core particle comprises a Janus particle. For example, in reference to Fig. 1, the inner core particle 102 disposed within the outer shell 108 is a Janus particle. Janus particles (JP), in embodiments, are particles on the nanometer, or micron, or millimeter scale with different optical properties owing to an anisotropic structure, for example, as described in Su et al., “Janus particles: design, preparation, and biomedical applications,” Materials Today Bio, Vol. 4, No. 100033, 2019, the entire contents of which are hereby incorporated by reference. In embodiments, JPs are objects composed of two or more parts that differ in their physical and chemical properties, often contrary in nature. In embodiments, the anisotropic structure of JPs contains optical, electrical, or magnetic properties, etc., which facilitate JPs with many advantages, such as multifunctional properties and ease of modification. In embodiments, JPs are manufactured by combining individual components together in a single-particle system, where the intrinsic chemical, magnetic, optical, and electronic properties of each domain are seldom altered or lost, allowing for unique properties of different parts to contribute in improving the chemical and physical properties of the whole.

[0178] In embodiments, one element of anisotropy in the Janus particle is in density and a second element of anisotropy is in the optical properties. For example, in embodiments and in reference to Fig. 1, the core particle 104 comprises a Janus particle, where the first material 104 has lower density than second material 104, where the materials possess distinct optical properties.

[0179] In embodiments, notwithstanding the presence of the core particle, the remaining interior volume of the GROVE particle includes one or more of a gas or mixture of gases, a liquid or mixture of liquids, a polymer or mixture of polymers, a semisolid, a solid material, or a combination or mixture of phases. In embodiments, the gas is air (e.g., an air substantially the same as atmospheric air). In embodiments, the interior volume comprises both a gas and liquid. In embodiments, the gas, liquid, polymer, solid, semisolid,or combination / mixture thereof, comprises a density that is greater than, substantially the same as, or less than the core particle, or the materials the core particle is composed of. In embodiments, the liquid is an aqueous liquid, organic liquid, mixed aqueous-organic mixture, a polymer, and / or a gel. In embodiments, liquid and / or the aqueous, or organic, mixed aqueous-organic mixtures, polymer, and / or gel contain one or more additives, preservatives, anti-oxidants, lubricants, emulsifiers, stabilizers, thickeners, anti-foaming agents, humectants, anti-bacterial agents, anti-caking agents, inorganic salts, pH adjusters, pH buffers, and rheology modifiers. In embodiments, the lubricant includes, but is not limited to, one or more of mineral oil, synthetic oil, grease, a silicone-based lubricant, a graphite-based lubricant, molybdenum disulfide, vegetable oils, and TEFLON-based lubricants.

[0180] In embodiments, the core particle disposed within the GROVE particle moves, or is configured to move or change its position, within the outer shell (e.g., independently of the outer shell). For example, in embodiments and in reference to Figs. 2A-2E, a set of illustrative side-view representations of various configurations of exemplary GROVE is illustrated (e.g., as in reference to Fig. 1), demonstrating that the inner core particle is configured to move within the outer shell, for example resting at an equilibrium or lowest- energy position (e.g., as shown in Fig. 2A), or adopting other positions within the outer shell (e.g., as shown in Figs. 2B-2E). In embodiments and in reference to Figs. 2A-2E, the arrow denotes the direction of the earth’s gravitational field relative to the GROVE particle and the core’s movement. In embodiments and in reference to Fig. 2A, the GROVE particle of Fig. 1 is shown in its lowest energy configuration, because the denser first material 104 within the core particle 102 is at the lowest possible position within the outer shell 108, which is the minimum of the gravitational potential energy. In embodiments and in reference to Fig. 2B, the GROVE particle of Fig. 1 is shown with the orientation of the core particle 102 having the first material 104 facing upward, but the core particle 102 is not at the lowest position within the shell (e.g., such as when the GROVE particle is dropped or shaken), and thus the core particle 102 is not in its lowest energy or equilibrium configuration within the GROVE particle. In embodiments and in reference to Fig. 2C, the core particle is rotated clockwise 90° relative to its position in Fig. 2A, which is again not a lowest energy configuration for the core particle within the shell. In embodiments and in reference to Figs. 2D and 2E, additional non-equilibrium configurations are shown in which the core particle is in contact with the inner surface of outer shell, but not in the lowest energy configuration. In embodiments, when the force acting upon the GROVE particle ceases, the core particle of Figs. 2B-2E will continue to move freely within the outer shell until coming to rest at the lowest energy configuration within the outer shell (e.g., the position at Fig. 2A).

[0181] In embodiments and in reference to Fig. 3, an illustrative side view of the operation of a 2D array of the GROVE particles (e.g., with reference to Fig. 1) are shown disposed on a surface, with the core particles 102 in a fixed position. Initially, in embodiments, the array of GROVE particles on the substrate is at equilibrium, with a heavier first material 104 of the core particles (denoted in cross-hatch) at the lowest possible points in their respective outer shells. In embodiments, an observer looking at the particles from above will see the optical properties associated with the top material of the particle (e.g., white in the illustration). After a stimulus is applied, in embodiments, the array of GROVE particles are no longer at equilibrium (e.g., the non-equilibrium state), with the core particles 102 occupying a subset of possible positions / orientations within the outer shell 108. In embodiments, there are a wide range of possible positions for the core particle 102 to adopt inside the shell, insofar as (a) the center of the particle is configured to occupy any possible set of x, y, z coordinates available within the shell (limited only by the radius of the core particle and outer shell), and (ii) the core particle is configured to exhibit rotational flexibility across all possible axes.

[0182] In embodiments and in reference to Fig. 3, in the non-equilibrium state, the observer looking from above observes a mixture of the optical properties of the top and bottom of the core particles (e.g., shown as a mixture of white and cross-hatch). In embodiments and in reference to Fig. 3, the bottom panel illustrates the effect of the force of gravity on the core particles to return to their lowest energy equilibrium position, where the observer again observes the top optical state (e.g., depicted as white).

[0183] In the three panels of Fig. 3, the position of the array of the GROVE particles does not vary: only the positions of the core particles disposed within the shell, which are shifted after stimulation and return back to equilibrium under the restorative force of gravity. In embodiments, there are a variety of ways to achieve this movement and optical change. In embodiments, the GROVE particle is disposed on a surface via application in a fluid composition (e.g., a paint, ink, lacquer, coating, varnish, glaze, gloss, toner, gel, formulation, solution, suspension, etc.), where the GROVE particles are left behind as a residual material on the surface (e.g., for example in a suspension with a volatile solvent). By contrast, a paint comprises pigment particles that when applied to a surface, the pigment particles do not change their position when the surface is moved, and the optical property observed is generally constant. In embodiments, the GROVE particles are adhered to a surface by an attractive force (e.g., electrostatic force) between the surface and the outer surface of the shell; alternatively, or additionally, the attractive force includes physisorption, adsorption, or non-covalent or covalent chemical bonding between the outer surface of the shell and the surface disposed thereon. Alternatively, in embodiments, one or more adherent is used, such as a glue, epoxy, bond, adhesive,cement, plaster, binder, gum, or fixative to dispose the GROVE particle and prevent its motion or release from the substrate.

[0184] In embodiments, a variety of stimuli are applicable to transition the inner core particle within a GROVE particle from the equilibrium configuration, e.g., shown in the array of particles in the top panel of Fig. 3. For example, in non-limiting embodiments, the force acting on the core particle includes a gravitational force (e.g., by tilting a surface containing GROVE particles), or a mechanical force (e.g., by shaking a surface containing GROVE particles, or by applying pressure to such a surface), or the force of acoustic radiation (e.g., with sound), or, if at least a portion of the core particle is magnetic, a magnetic force, or, in the presence of an electric field, electrostatic force. In embodiments, the GROVE particle exhibits a change in an optical property as a function of exposure to a force, where the force is one or more of a gravitational force, mechanical force, pressure, acoustic radiation (e.g., sound), magnetic force, and electrostatic force.

[0185] In embodiments, the one or more core particles are configured to transition from an equilibrium position to one or more non-equilibrium positions.

[0186] In embodiments, the one or more core particles re-establishes the equilibrium position (e.g., relaxation) from the one or more non-equilibrium positions due to a restoring force, and thus to an initial optical state. In embodiments, and in reference to Fig. 3, gravitational force acting over time re-establishes the equilibrium configuration of the inner core particles within the GROVE particles. In embodiments, the time required to re-establish equilibrium is adjusted based on the magnitude of the applied force and gravitational restoring force, the control of friction, the shape and dimensions of the core particle and the outer shell, the chemical compositions of both, the presence of additional elements within the outer shell (e.g., lubricants), as well as other factors. In embodiments, the time to reestablish equilibrium varies from about or at least about 1 ms to about or at least about 1 min. In embodiments, the re-establishment of equilibrium (e.g., in the absence of additional acting forces) occurs in about or less than about 1 ms, about or less than 2 ms, about or less than 3 ms, about or less than 4 ms, about or less than 5 ms, about or less than 6 ms, about or less than 7 ms, about or less than 8 ms, about or less than 9 ms, about or less than 10 ms, about or less than 12 ms, about or less than 14 ms, about or less than 16 ms, about or less than 18 ms, about or less than 20 ms, about or less than 25 ms, about or less than 30 ms, about or less than 35 ms, about or less than 40 ms, about or less than 45 ms, about or less than 50 ms, about or less than 55 ms, about or less than 60 ms, about or less than 65 ms, about or less than 70 ms, about or less than 75 ms, about or less than 80 ms, about or less than 85 ms, about or less than 90 ms, about or less than 95 ms, about or less than 100 ms,about or less than 125 ms, about or less than 150 ms, about or less than 175 ms, about or less than 200 ms, about or less than 250 ms, about or less than 300 ms, about or less than 350 ms, about or less than 350 ms, about or less than 400 ms, about or less than 450 ms, about or less than 500 ms, about or less than 600 ms, about or less than 700 ms, about or less than 800 ms, about or less than 900 ms, about or less than 1 s, about or less than 2 s, about or less than 3 s, about or less than 4 s, about or less than 5 s, about or less than 6 s, about or less than 7 s, about or less than 8 s, about or less than 9 s, about or less than 10 s, about or less than 20 s, about or less than 30 s, about or less than 40 s, about or less than 50 s, or about or less than 1 min, including time periods and ranges of time therebetween.

[0187] In embodiments, GROVE particles comprise a wide variety of shapes. For example, in nonlimiting embodiments, Figs. 4A-4L depict a series of exemplary GROVE particles in equilibrium orientations (e.g., where Fig. 4A correspondence to the GROVE particle 100 of Fig. 1). In embodiments, and in reference to Fig. 4B, the core particle is substantially the same size as the core particle in Fig. 4A, and the outer diameter of the outer shell is likewise substantially the same as the outer shell in Fig. 4A; however, in Fig. 4B, the overall shell thickness is greater, meaning that the core particle of Fig. 4B occupies a larger fraction of the interior volume of the outer shell relative to the core particle of Fig. 4A. In embodiments, and in reference to Fig. 4C, both the outer and inner diameters of the shell are substantially the same as depicted in Fig. 4A; however, the dimensions of the core particle are greater. In embodiments, and in reference to Figs. 4D and 4E, the GROVE particle is configurable for 2 core particles (e.g., as shown in Fig. 4D) or more than 2 core particles (e.g., as shown in Fig. 4E). In embodiments, and in reference to Fig. 4D, there are two core particles, each smaller in diameter than the core particle of Fig. 4A, disposed in a single layer, whereas in Fig. 4E, there are 7 core particles disposed in three layers. In embodiments, the GROVE particle has 1, 2, 3, 4, 5, 6, 7, 8, 9, about or at least about 10, about or at least about 12, about or at least about 14, about or at least about 16, about or at least about 18, about or at least about 20, about or at least about 25, about or at least about 30, about or at least about 35, about or at least about 40, about or at least about 45, about or at least about 50, about or at least about 100, about or at least about 200, or more than 200 core particles, including numbers of core particles therebetween, disposed within a single GROVE particle. Likewise, in embodiments, the core particles are arranged in 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, or about or at least 10 layers of core particles in a single GROVE particle.

[0188] In embodiments with 2 or more core particles, the particles are equivalent in size. In embodiments with 2 or more core particles, the particles are monodisperse. In embodiments with 2 or more core particles, the particles are differently-sized. In embodiments with 3 or more core particles, the particlesare polydisperse. In embodiments, GROVE particles, in any arrangements or sets as described herein, are polydisperse. In embodiments with 3 or more core particles, there are two or more sets of monodisperse particles.

[0189] In embodiments having two or more GROVE particles, the GROVE particles each exhibit substantially equivalent optical properties (and optical property changes in response to stimuli).

[0190] In embodiments having two or more GROVE particles, the GROVE particles each exhibit distinct optical properties. For example, in embodiments and in reference to Figs. 35A-35C and 36A-36F, a substrate or surface comprises two or more different pluralities of GROVE particles. In such embodiments, the two or more difference pluralities of GROVE particles differ in the amount / type of force needed for optical change, the optical change exhibited, the relaxation time, etc. In embodiments, Figs. 36A-36F shows the differences in combinations of optical features observed by a hypothetical observer, for example, in Figs. 36C-36D, where a “rainbow effect” (e.g., multiple colors observed) is observed. In embodiments, a “rainbow effect” is obtained by arranging GROVE particles in a pattern based on color and / or relaxation time such that a wave of color change is observed as the core particles move in response to a force. In embodiments, the GROVE particles are segmented (e.g., spatially segregated as shown in Fig. 36F) based on the amount / type of force needed for optical change, the optical change exhibited, the relaxation time, etc. In embodiments, GROVE particles are not segmented.

[0191] In embodiments, collections of GROVE particles exhibit different relaxation times. In embodiments, the relaxation times for different GROVE particles vary on the order of 0.01 s (milliseconds), 0.1 s (tenths of a second), or by seconds.

[0192] In embodiments, the GROVE particle and / or individual core particle(s) comprises a shape substantially similar to one or more of a truncated teardrop shape, champagne flute shape, wine glass shape, round-bottomed shape, tumbler shape, egg-shape, paraboloid, prolate hemispheroid, oblate hemispheroid, hemispherical, elliptical, cylindrical, trigonal pyramid, pentagonal pyramid, hexagonal pyramid, a regular polygonal shape with a truncated portion, a truncated square pyramid, a truncated cone, a truncated cone where the top plane and bottom plane are not parallel. In embodiments, the shape is substantially concave and / or convex 3-dimensional shape. In embodiments, the terms “approximately” or “substantially” in reference to shapes / geometries of particles refers to the general shape / geometry and any and all variations that would reasonably be construed or described as resembling the form of that shape / geometry.

[0193] In embodiments, and in reference to Fig. 4A, the first material is a less dense optical material (e.g., shown in white) and the second material is a denser optical material (e.g., shown in cross-hatch), where each occupies roughly one hemisphere of the spherical core particle. In embodiments, and in reference to Fig. 4F, the first, less dense optical material occupies most of the volume of the core particle, while the second, denser optical material occupies less volume. In embodiments, the less dense optical material or the denser optical occupies about or at least about 1%, 2% 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12% 14%, 16%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, or more than 90%, such that the sum of the percentages of the at least two materials add to 100%.

[0194] In embodiments, the core particles include and / or adopt a variety of shapes. For example, in non-limiting embodiments and in reference to Fig. 4G, the core particle is approximately egg-shaped, with optical materials of different densities in the top and bottom parts of the egg; in Fig. 4H the core particle is shaped like the top of a wine glass, with different optical materials disposed on the left and ride sides; in Fig. 4I, the core particle is a cylinder, with the bottom part of the cylinder comprising a denser optical material and the top part comprising a less dense optical material; in Fig. 4J, the core particle is spherical as in Fig. 4A, but the core particle is coated with a layer of smaller particles (e.g., shown as gray). In embodiments, the core particle coating is isotropic or anisotropic and is composed of one or more materials and / or optically active agents. In embodiments, and in reference to Fig. 4K, the core particle comprises two distinct spherical particles joined together by covalent bonds, non-covalent bonds, or other attractive forces. In embodiments, the core particle is composed of 2 or more smaller geometrical shapes (e.g., cubes, rectangles, pyramids, spheres, etc.) which are composed of the same or different material, where each has either the same or distinct densities and / or optical properties. In embodiments, and in reference to Fig. 4L, the core particle is a cube, and lacks curved surfaces.

[0195] In embodiments, the outer shell of the GROVE particle is continuous or discontinuous, spherical or non-spherical, and exhibits smooth or rough surfaces (e.g., inner and / or outer). For example, in non-limiting embodiments, Figs. 5A-5E depict a series of GROVE particles at stationary equilibrium orientations with various types of outer shells. In embodiments, and in reference to Fig. 5A, a GROVE particle substantially similar to Fig. 1 is shown, whereas in Fig. 5B a GROVE particle with a discontinuous, porous, or otherwise incomplete outer shell is shown. In embodiments, such a design allows for a gas, liquid, semisolid, or other matter to permeate through the outer shell into the interior volume, where the substance is able to alter the position of the core particle, resulting in an optical property change depending upon the nature of the interaction. In embodiments, any external shell configuration is acceptable in GROVE particles such that (i)the external shell does not move in response to the stimulus, and (ii) the inner core particle remains confined within the outer shell. Thus, in embodiments, the outer shell is thick and / or strong enough not to rupture during the movement of the core particle, and if discontinuous or porous, there are no discontinuities ( / .e., pores or holes) large enough for the core particle to escape. In embodiments, the discontinuities in the shell comprise about or up to about 0.1 %, about or up to about 1 %, about or up to about 10%, about or up to about 50% or more of the total surface area of the outer shell, provided that none of the pores have a cross-sectional dimension that is larger than the smallest external dimension of the core particle.

[0196] In embodiments, the outer shell of the GROVE particle is not spherical, or is not substantially spherical. For example, in embodiments, and in reference to Figs. 5C-5D, the outer shell has an elliptical shape (e.g., as shown in Fig. 5C). In embodiments, the GROVE particle, the core particle(s), and / or the outer shell had a shape / geometry that has one or more axes of symmetry; alternatively, in embodiments, each have a shape / geometry that is asymmetrical. For example, in embodiments and in reference to Fig. 5D, the outer shell possess a shape with no elements of symmetry. Likewise, in embodiments, it is not a requirement that the outer shell of a GROVE particle exhibit uniform thickness, as also demonstrated by the particle in Fig. 5D. In embodiments, the outer and / or inner surfaces of the shell of GROVE particles is smooth and / or rough. In embodiments, and in reference to Fig. 5E, there is a regular pattern of roughness features (shown as hemispheres) on the inner surface of the shell 500. However, in embodiments, the roughness features do not need to be regularly-shaped, or cover an entire surface; for example as shown in Fig. 5F, two roughness features (e.g., shown in gray) are distinct from one another, and do not cover the entire outer surface. In embodiments, the one or more roughness features is a variation in a surface smoothness that alters the degree of reflectivity of the surface at one or more wavelengths, and / or affects the movement, friction, or packing features of the core particle(s) and shell. In embodiments, and in reference to Fig. 37, “raspberryshaped” core particles are shown where “lobes” are grown onto the surface of core particles, which may function as roughness features.

[0197] In embodiments, for example as depicted in the GROVE particle of Fig. 1, there is a correspondence between the density and the optical properties within the core particle: the less dense first material 104 has one set of optical properties, and the denser second material 106 has a distinct set of optical properties, where and they are spatially aligned. However, in embodiments, the optical properties do not need to correspond to the mass distribution. For example, in non-limiting embodiments, Figs. 6A-6G depict GROVE particles where optical property is not directly correlated to the density differences. In embodiments, and in reference to Fig. 6A, a GROVE particle substantially similar to Fig. 1 is illustrated, where theassociated coloration corresponds to the densities of material such that the top hemisphere of the core particle is a first color (e.g., depicted as white), and the bottom hemisphere is a second color (e.g., depicted by cross-hatch). In embodiments, and in reference to Fig. 6B, the mass distribution of the core particle is such that at equilibrium, the left hemisphere of the core particle exhibits one optical state (e.g., depicted by cross-hatch), and the right hemisphere exhibits a different optical state (e.g., depicted as white). In embodiments, and in reference to Fig. 6C, the mass distribution of the core particle is such that at equilibrium, the two hemispheres associated with the different optical states are tilted with respect to both the horizontal and vertical axes. In Figs. 6D-F, one or more mass-altering material (e.g., particles denoted by black filled circles) are added to influence the mass distribution. In embodiments, such mass-altering materials are particles that added similar to material doping, where materials of higher or lower density are manufactured into the core particle to alter the density. In embodiments, the mass-altering materials represent spaces or voids, which subtract material and lower the density. In embodiments and in reference to Figs. 6D and 6E, the positioning of the higher-density material (e.g., black circles) corresponds to the positioning of distinct optical materials, such that the optical properties of the GROVE particles of Figs. 6D and 6E are identical to that of the GROVE particle of Fig. 6A (notwithstanding any optical properties associated with the particles). In embodiments, the mass-optical property correspondence is not present in the GROVE particle, for example as shown in Fig. 6F, where a mass-altering particle resides at the bottom between the interface of the two hemispheres of different optical materials, such that at equilibrium, one of the hemispheres is facing left while the other is facing right. In embodiments, and in reference to Fig. 6G, the equilibrium configuration of the GROVE is such that the two hemispheres corresponding to different optical states of the core particle are not aligned neither horizontally as in Figs. 6A, 6D, and 6E, nor vertically as in Fig. 6F, and the mass-altering material is not at the interface between the hemispheres.

[0198] In embodiments, additional elements to modify the functionality of the GROVE particle are present. In embodiments, and in reference to Fig. 7A, a GROVE particle substantially similar to that in Fig. 1 is shown which comprises at least an outer shell and an encapsulated core particle. In embodiments, and in reference to Figs. 7B and 25A-25B, the core particle is at least partially covered with one or more coating material(s). In embodiments, and in reference to Figs. 25A-25B, a side-view of a core particle is shown where a material is coated onto a portion of the surface to make the core particle heavier (Fig. 25B) or lighter (Fig. 25A) on one portion. In embodiments, the coating material is thick or thin (e.g., relative to the dimensions of the core particle), smooth or rough, conformal or non-conformal, porous or non-porous, comprise a single layer or multiple layers, be optically transmissive or partially transmissive, and comprise one or more organicsubstances, one or more inorganic substances, one or more biological substances, or any combination of organic, inorganic, and / or biological substances. In embodiments, the coating material is used to alter the impact of friction (e.g., used to mitigate friction or increase friction) on the movement of the core particle within the shell. In embodiments, coating materials include lubricants, surface treatments and / or coatings (e.g., TEFLON, polytetrafluoroethylene (PTFE), hydroxylated self-assembled monolayers, vitreous enamel, etc.), polishing (e.g., with ceria (cerium oxide), etc.), materials with lower coefficients of friction relative to the shell and / or core particle (e.g., ceramics, anodized metals, silica, etc.).

[0199] In embodiments, the one or more coating materials is or comprises a chemical functionalization covering at least a portion of the outer shell. In embodiments, the one or more coating materials is or comprises a swellable material covering the core particle.

[0200] In embodiments, and in reference to Fig. 7C, the core particle is suspended or otherwise shares the internal volume with a fluid or liquid. In embodiments, the fluid or liquid is a polymer or gel, an aqueous solution, or an organic liquid. In embodiments, the GROVE particle has an interior volume of X, and core particle (or particles) with a volume of Y, where the fluid or liquid in the GROVE particle (e.g., as shown in Fig. 7C) occupies up to about 100% of the difference between volumes (X-Y), or about 99%, or about 98%, or about 97%, or about 96%, or about 95%, or about 94%, or about 93%, or about 92% or about 91% or about 90%, or about 85%, or about 80%, or about 70%, or about 60%, or about 50%, or about 40%, or about 30%, or about 20%, or about 15%, or about 10%, or about 9%, or about 8%, or about 7%, or about 6%, or about 5%, or about 4%, or about 3%, or about 2%, or about 1 %, or about 0.5%, or about 0.2%, or about 0.1 %, or about 0.01 %, or about 0.001 % of the difference between the volumes, including volumes therebetween.

[0201] In embodiments, and in reference to Figs. 29A-29E, GROVE particles are shown in varying levels of the internal volume being filled with liquid, with varying differences in density relative to the core particle. For example, in embodiments and in reference to Fig. 29A, the core particle is less dense than a liquid which fills the internal founded volume, resulting in the core particle floating on top of the liquid. For example, in embodiments and in reference to Fig. 29B, the core particle has substantially the same density as a liquid which fills the internal founded volume, resulting in the core particle exhibiting some degree of buoyancy within the liquid. For example, in embodiments and in reference to Fig. 29C, the core particle is more dense than a liquid which fills the internal founded volume, resulting in the core particle sinking within the liquid. In embodiments, the contour of a surface inside of the shell is modified to alter the movement ofthe core particle within the GROVE particle. For example, in embodiments and in reference to Fig. 29D, a liquid permeates the shell and is polymerized, cured, or otherwise hardened for example, using a porous shell material to allow the liquid to permeate the shell and be cured in place. In embodiments, and in reference to Fig. 29D, the substantially flattened bottom portion provides a surface for the core particle to rest upon and alters the rolling movement within the shell. In embodiments, the contour of the surface is altered to be substantially flat, or curved (convex or concave). In embodiments, the curvature is distinct (opposite) the curvature of the shell, such that it minimizes the points of contact with the core particle. In embodiments, and in reference to Fig. 29E, curable liquid is used to adhere the core particle to the internal surface of the shell, such that a sufficiently large force is needed to break the core particle loose enough to exhibit a change in optical property (e.g., a color change if an object has received a large force, such as being dropped).

[0202] In embodiments, and in reference to Fig. 7D, one or more substances are associated with the inner surface of outer shell of the GROVE particle. In embodiments, the substances are associated by electrostatics, adsorption, or by non-covalent or covalent chemical bonding. In embodiments, where a GROVE particle with an interior volume of X, and core particle (or particles) volume of Y, the one or more substances associated with the inner surface of the shell of the GROVE particle (e.g., as shown in Fig. 7D) occupies up to about 90% of the difference between volumes (X-Y), or about 85%, or about 80%, or about 70%, or about 60%, or about 50%, or about 40%, or about 30%, or about 20%, or about 15%, or about 10%, or about 9%, or about 8%, or about 7%, or about 6%, or about 5%, or about 4%, or about 3%, or about 2%, or about 1 %, or about 0.9%, or about 0.8%, or about 0.7%, or about 0.6%, or about 0.5%, or about 0.4%, or about O.3%, oraboutO.2%, or about 0.1%, orabout0.05%, oraboutO.25%, or about 0.01 %, or about 0.005%, or about 0.001%, or about 0.0001 % of the difference between volumes, including volumes therebetween.

[0203] In embodiments, and in reference to Fig. 7E, the GROVE particle includes, in addition to the core particle, additional particles (e.g., such as the 4 smaller particles shown as gray). In embodiments, such as depicted in Fig. 7E, each of the additional particles is smaller than the core particle(s). In embodiments, the GROVE particle comprises from a single core particle to about or at least about 5000 core particles, for example having 1 , 2, 3, 4, 5, 6, 7, 8, 9, about or at least about 10, about or at least about 12, about or at least about 14, about or at least about 16, about or at least about 18, about or at least about 20, about or at least about 25, about or at least about 30, about or at least about 35, about or at least about 40, about or at least about 45, about or at least about 50, about or at least about 100, about or at least about 200, about or at least about 300, about or at least about 400, about or at least about 500, about or at least about 1000, about or at least about 2000, or about or at least about 5000 or more smaller particles in a GROVE particle, includingnumbers therebetween. In embodiments, such smaller particles are “satellite particles,” which are smaller contaminating particles that arise during the manufacture of the core particle and are consequently encapsulated within the shell. In embodiments, the additional particles function similarly to ball bearings (e.g., or needle bearings with a cylindrical core particle) to assist in the movement of the core particle within the shell. In embodiments, the additional particles are optically transmissive to allow optical properties from the core particle to show.

[0204] In embodiments, and in reference to Fig. 7F, several stimuli-responsive core particles are present within a single GROVE particle. Additionally, in embodiments and in reference to Fig. 7F, one or more additional particles is present (e.g., shown in gray) that is larger than the one or more core particles. In embodiments, the larger particle is surrounded by core particles. In embodiments, the larger particle is in any location within the shell in relation to the core particle. Likewise, in embodiments, (e.g., as shown in Fig. 7E) the GROVE particle comprises any number of core particles, including for example, 1 , 2, 3, 4, 5, 6, 7, 8, 9, about or at least about 10, about or at least about 12, about or at least about 14, about or at least about 16, about or at least about 18, about or at least about 20, about or at least about 25, about or at least about 30, about or at least about 35, about or at least about 40, about or at least about 45, about or at least about 50, about or at least about 100, about or at least about 200, core particles 400, and any number of larger particles(in relation to the core particle), including for example, 1 , 2, 3, 4, 5, 6, 7, 8, 9, about or at least about 10, about or at least about 12, about or at least about 14, about or at least about 16, about or at least about 18, about or at least about 20, about or at least about 25 particles.

[0205] In embodiments, described herein is a composition comprising gravity-responsive optically- variable encapsulated (GROVE) particles. In embodiments, the composition comprises GROVE particles suspended in a liquid or carrier fluid or ink. In embodiments, the liquid comprises a solvent or dispersing agent. In embodiments, the liquid incorporates one or more of an emulsifier, surfactant, solvent, humectant, viscosity modifier, salt, rheological agent, anti-microbial agent, pH adjuster, solvent buffer, binder, resin, glue, gloss additive, adhesion additive, wax, slip agent, leveling agent, plasticizer, defoamer, anti-settling agent, biocide, chelating agent, conductive agents, drying accelerator, pigment, dye, wetting agent, anti-wetting agent, UV stabilizer, drying accelerator, suspending agent, optical brightener, matting agent, biological polymer, synthetic polymer, and organic molecule.

[0206] In embodiments, the GROVE particle(s) are present in solution, on a surface, or in / on a film. For example, in embodiments and in reference to Figs. 8A-8H, a series of side-view ortilted-view representationsof collections or assemblies of GROVE particles are illustrated. In embodiments, and in reference to Figs. 8A-8B, GROVE particle substantially similar to that of Fig. 1 is shown suspended in liquid solutions (e.g., in beakers); in Fig. 8A, the core particles are in a non-equilibrium orientation, while in Fig. 8B, the core particles are in the lowest energy configuration. In embodiments, there are additional components in the liquid, including but not limited to, emulsifiers, surfactants, co-solvents, viscosity modifiers, salts, rheological agents, anti-microbial agents, pH adjusters, buffers, suspending agents, biological polymers, synthetic polymers, and organic molecules. Likewise, measured either by weight or by volume, in embodiments, GROVE particles occupy any fraction of the liquid or solution, including for example, about or less than about 0.001% (w / v), about 0.1 % (w / v), about 0.5% (w / v), about 1 % (w / v), about 2% (w / v), about 3% (w / v), about 4% (w / v), about 5% (w / v), about 6% (w / v), about 7% (w / v), about 8% (w / v), about 9% (w / v), about 10% (w / v), less than or about 12% (w / v), less than or about 14% (w / v), less than or about 16% (w / v), less than or about 18% (w / v), less than or about 20% (w / v), less than or about 25% (w / v), less than or about 30% (w / v), less than or about 35% (w / v), less than or about 40% (w / v), less than or about 50% (w / v), less than or about 60% (w / v), or less than or about 70% (w / v), including volumes therebetween.

[0207] In embodiments, the composition comprises GROVE particles arranged in an array on a substrate. In embodiments, the substrate comprises a thin film, plastic, polymer, and / or paper substrate. In embodiments, the array is a monolayer of particles. In embodiments, the array comprises two or more layers of particles. In embodiments, the GROVE particles are sandwiched between two or more substrate layers. In embodiments, the optical effect is different when viewed from above compared to when viewed from below a plane of GROVE particles arranged in or on the substrate and / or film, optionally wherein the plane of GROVE particles are arranged between or on a transparent substrate or film-based substrate. In embodiments, the GROVE particles are suspended, crosslinked, or embedded in a material (e.g., thermally- responsive, UV-crosslinkable, etc., material).

[0208] In embodiments, and in reference to Fig. 31, the optical change is irrespective of height (e.g., z height) relative to the observer. For example, in embodiments with multiple layers of GROVE particles, if a top layer is optically blocking or obscuring one or more lower layers (e.g., one or more layers underneath the top layer in the z height relative to the observer), then the optical property and any changes thereto are still observable from the top by the observer (irrespective of blocking layers below). In embodiments, and in reference to Fig. 31, a top-down view of particles is shown, where the topmost plane of particles is shown, but the bulk optical property below is identical to what would be seen on the top.

[0209] In embodiments, and in reference to Figs. 26A-26B, GROVE particles are suspended in a carrier fluid which is amenable to crosslinking, a curing process, and / or hardening of the carrier fluid to create a matrix that embeds the GROVE particles suspended therein. For example, in embodiments, this is achieved by polymerization, hardening, curing, etc., of the carrier fluid (e.g., of a varnish, epoxy, UV / thermal crosslink, etc.). In embodiments, the shell of the GROVE particle is immobilized in the carrier matrix after it is applied, substantially simultaneously to being applied, or before it is applied. In embodiments, the carrier fluid and / or matrix is UV-crosslinkable, thermally-crosslinkable, photo-crosslinkable, etc. In embodiments, GROVE particles are applied to substrate, and the substrate is crosslinked to the GROVE particle.

[0210] In embodiments, and in reference to Figs. 8C, 8D, 8E, and 8F, assemblies of GROVE particle (substantially similar to Fig. 1) are shown on planar or approximately planar surfaces. In embodiments, and in reference Fig. 8C, the GROVE particles are disposed in a random two-dimensional array, where and the core particles are in a non-equilibrium configuration, and thus exhibiting a mix of optical property when viewed from above. In embodiments, and in reference Fig. 8D, the GROVE particles are disposed in a random two- dimensional array, and the core particles are in the lowest-energy equilibrium configuration, and thus exhibiting a homogenous optical property when viewed from above.

[0211] In embodiments, and in reference to Fig. 8C, the GROVE particles are substantially equivalent in size, while in Fig. 8D, there are 12 larger GROVE particles and 7 smaller GROVE particles shown. In embodiments, arrays of GROVE particles on surfaces comprise 1 , 2, 3, 4, 5, 6, 7, 8, 9, about or at least about 10, or more than 10, different compositions of GROVE particles. In embodiments, suspensions, substrates, films, and / or objects comprise different GROVE particles (e.g., different in size, construction, optical properties, etc.).

[0212] In embodiments, and in reference to Fig. 8C, approximately 50% of the square surface area shown is covered by GROVE particles, while the large and small particles in Fig. 8D combine to cover approximately 65% of the surface shown. In embodiments, the fractional surface coverage is about or less than about 1%, about or less than about 5%, about or less than about 10%, about or less than about 15%, about or less than about 20%, about or less than about 25%, about or less than about 30%, about or less than about 35%, about or less than about 40%, about or less than about 45%, about or less than about 50%, about or less than about 55%, about or less than about 60%, about or less than about 65%, about or less than about 70%, about or less than about 75%, about or less than about 80%, about or less than about 85%,about or less than about 90%, about or less than about 95%, or about or less than about 99%, including fractional surface coverages therebetween.

[0213] Additionally, in embodiments, particles such as those shown in Figs. 8C-8D are covered by a top surface or substrate. In embodiments, the bottom surfaces, such as those shown in Figs. 8C and 8D, and the top surface, such as that shown in Fig. 8D, comprise a wide variety of materials, including but not limited to glass, sapphire, diamond, silicon, organic polymers, organic materials, biological polymers, and metal oxides. In embodiments, the GROVE particle(s) are sandwiched between organic and / or nonorganic polymers both above and below, for example, considered to be embedded within a film. In embodiments, the film, surface, polymer, and / or substrate the GROVE particle(s) are disposed upon (or embedded between) comprises a material that is transparent to at least a portion of the visible electromagnetic (EM) spectrum, including for example, glass, quartz, plastic, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers (TPE), acrylonitrile butadiene styrene (ABS), epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer (COC) cyclic olefin polymer (COP), poly dimethyl siloxane (PDMS), poly ether ester ketone (PEEK), polyetherimide (ULTEM) and / or nylon.

[0214] In embodiments, such a film, surface, polymer, and / or substrate has an overall thickness of about or less than about 1 pm, about or less than about 2 pm, about or less than about 3 pm, about or less than about 4 pm, about or less than about 5 pm, about or less than about 6 pm, about or less than about 7 pm, about or less than about 8 pm, about or less than about 9 pm, about or less than about 10 pm, about or less than about 12 pm, about or less than about 13 pm, about or less than about 14 pm, about or less than about 15 pm, about or less than about 16 pm, about or less than about 17 pm, about or less than about 18 pm, about or less than 19 pm, about or less than about 20 pm, about or less than about 21 pm, about or less than about 22 pm, about or less than about 23 pm, about or less than about 24 pm, about or less than about 25 pm, about or less than about 26 pm, about or less than about 27 pm, about or less than about 28 pm, about or less than about 29 pm, about or less than about 30 pm, about or less than about 31 pm, about or less than about 32 pm, about or less than about 33 pm, about or less than about 34 pm, about or less than about 35 pm, about or less than about 36 pm, about or less than about 37 pm, about or less than about 38 pm, about or less than about 39 pm, about or less than about 40 pm, about or less than about 41 pm, about or less than about 42 pm, about or less than about 43 pm, about or less than about 44 pm, about or less than about 45 pm, about or less than about 46 pm, about or less than about 47 pm, about or less than about 48 pm, about or less than about 49 pm, about or less than about 50 pm, about or less than about 55 pm, about or less thanabout 60 pm, about or less than about 65 pm, about or less than about 70 pm, about or less than about 75 pm, about or less than about 80 pm, about or less than about 90 pm, about or less than about 100 pm, about or less than about 200 pm, about or less than about 500 pm, or about or less than about 1 mm, including thicknesses therebetween.

[0215] In embodiments, either the top substrate, or the bottom substrate, or both substrates contains structural elements. For example, in embodiments and in reference to Fig. 8G, a side post is shown associated with a bottom substrate. In embodiments, and in reference to Fig. 8H, a hemisphere is associated with the top substrate. In embodiments, structural elements include, but are not limited to, posts, detents, hemispheres, regular shapes, irregular shapes, grooves, bumps, indentations, prisms, walls, or barriers. In embodiments, structural elements comprise the same composition as the substrates with which they are associated, or the structural elements could comprise 1, 2, 3, or more than 3 different materials. In embodiments, the structural elements function to maintain the position of the GROVE particle(s) with respect to the film, surface, polymer, and / or substrate associated therewith.

[0216] In embodiments, the structural elements, for example shown in Figs. 8G-8H, are used to control the placement, orientation, positioning, packing, and / or movement of the GROVE particles. In embodiments, structural elements are used to control the spacing or the positioning, or the alignment of the top and bottom substrates. In embodiments, the structural elements are ornamental, for example, to provide uniqueness in the arrangement or design of the particles. In embodiments, the structural elements serve as a fiduciary mark, denoting one or more positions. In embodiments, the structural elements have two or more different functions.

[0217] In embodiments, the structural elements are associated with the corners of a substrate (e.g., 4 for a square), with the edges of a substrate, with the interior of a substrate, and / or combinations thereof. In embodiments, the arrangement of GROVE particles includes one or more number of structural elements (e.g., as a fiduciary mark, arrangement of particles, integrity of substrate, etc.), including for example, 2, 3, 4, 5, 6, about or at least about 10, about or at least about 50, about or at least about 100, about or at least about 300, about or at least about 500, about or at least about 1 ,000, about or at least about 5,000, about or at least about 10,000, about or at least about 100,000, or aboutor at least about 1 ,000,000. In embodiments, the density of structural elements per unit area of substrate include about or at least about 1 element / sq. inch, or about or at least about 2 / sq. inch, or about or at least about 3 sq. inch, or about or at least about 4 sq. inch, or about or at least about 5 sq. inch, or about or at least about 10 sq. inch, or about or at least about1 OO / sq . inch, or about or at least about 1000 / sq. inch, or about or at least about 10,000 / sq. inch, or about or at least about 100, 000 / sq. inch, or about or at least about 1 ,000, 000 / sq. inch, including particle densities therebetween.

[0218] In embodiments, the substrates or surfaces associated with the placement of GROVE particles are planar and / or non-planar. For example, in embodiments and in reference to Figs. 8C-8G, one or more planar substrates are shown. In embodiments, and in reference to Fig. 8H, the bottom substrate is non-planar or “rough.” In embodiments, the roughness associated with a substrate includes regular roughness (e.g. in a pattern) or irregular. In embodiments, the scale of roughness is small in comparison to the dimensions of associated GROVE particles, approximately the same as the dimensions of associated GROVE particles, and / or substantially larger than the dimensions of associated GROVE particles.

[0219] In embodiments, the optical properties of the top and / or the bottom substrate is related to the optical properties of the associated GROVE particles. In embodiments, the optical properties of the top and / or the bottom substrate is distinct from the GROVE particles. In embodiments, the color of the substrate is the same as the top of the core particle such that, at equilibrium, the GROVE particle is partly or completely obscured and / or blends into the background of the substrate.

[0220] In embodiments, and in reference to Figs. 9A-9D, a series of side-view representations of assemblies of GROVE particles as illustrated, where the majority of core particle comprises a lighter-colored, denser portion (e.g., shown in gray), and a small amount of a darker-colored, less dense portion (e.g., shown in black). In embodiments, and in reference to Fig. 9A, the particles are disposed on a substrate at stationary, upright equilibrium position. In embodiments, and in reference to Fig. 9B, the particles are disposed on a substrate at equilibrium, with the substrate being the same color as the lower portion of the core particle. In embodiments, and in reference to Fig. 9C, the particles are disposed on a substrate at equilibrium, with the substrate being the same color as the upper portion of the particles. In embodiments, and in reference to Fig. 9D, the particles appear on a tilted substrate, in which the tilt causes the core particles to roll within the shell (by virtue of the force of gravity) to their lowest energy configuration, exhibiting distinct optical properties depending upon the angle of observation.

[0221] In embodiments, changing the configuration of particles with respect to the direction of irradiation changes the transmission of radiation (e.g., light) through a collection of GROVE particles. For example, in embodiments and in reference to Fig. 10, (for simplicity, the outer shells of the GROVE particles are not shown), the core particle size is large with respect to the irradiation wavelength, such that the top half of thecore particle transmits light from the source, while the bottom half exhibits extinction of the irradiation (e.g., through reflection, scattering, absorbance, etc., or a combination of effects). In embodiments, the net effect is that, for a particle with two equally-sized hemispheres (e.g., as shown in Fig. 10), the transmission through the particle is 50%. In embodiments, when force acts on the particles (e.g., the force of gravity, a mechanical force, a magnetic force, sound, etc.) such that the orientation of the particles is rotated by approximately 90° clockwise (or counterclockwise), the irradiated light impinges on the high-extinction part of the core, the net transmission is substantially 0%.

[0222] In embodiments, the GROVE particles (e.g., as shown Fig. 10) are not associated with a surface, i.e., they are suspending in the gas phase (e.g., air), or suspended in a liquid (e.g., aqueous phase). In embodiments, GROVE particles that exhibit differential transmission, reflection, absorption, and / or scattering between equilibrium and non-equilibrium states are suspended in the gas phase, liquid phase, and / or associated with a surface. In embodiments, such GROVE particles imbue the gas, liquid, and / or substrate with an obscurant and / or optical property changing effect that is direction with the applied force. In embodiments, the GROVE particles are ordered, disordered, or semi-ordered. In embodiments, the GROVE particles are confined to a 2-D structure, or exist in a 3-D orientation.

[0223] In embodiments, the difference in the optical properties between equilibrium and non-equilibrium states is slight (about or less than about 1 % in magnitude), or large (about or nearly about 100% in magnitude). In embodiments, the difference is about or at least about 1 %, or about or at least about a 2% difference, or about or at least about a 3% difference, or about or at least about a 4% difference, or about or at least about a 5% difference, or about or at least about a 10% difference, or about or at least about a 20% difference, or about or at least about a 30% difference, or about or at least about a 40% difference, or about or at least about a 50% difference, or a difference greater than 50%, including differences therebetween.

[0224] In embodiments, there are multiple stimuli that are used to move GROVE particles from equilibrium to non-equilibrium configurations. For example, in embodiments and in reference to Fig. 11A- 11C, a series of representations illustrate the use of sound to perturb GROVE particles from equilibrium to non-equilibrium configurations, resulting in changes in the optical properties. In embodiments and in reference to Figs. 11 A-11 C, an array of GROVE particles with the lower-density hemisphere shown in white, and the higher-density hemisphere shown in black, are shown in the equilibrium configuration, where when laying substantially still, the surface appears as the color of the lower-density hemisphere (e.g., white). In embodiments, and continuing in reference to Figs. 11 A-11 C, the GROVE particle array is associated with anobject, for instance in non-limiting examples a banknote, where an observer sees the GROVE array as being white. In embodiments, the introduction of vibration frequencies as sound (e.g., in the case of Fig. 11B, originating from a mobile phone) imparts an acoustic force, causing the core particles to move within the shell, adopting a mixture of orientations, as shown in Fig. 11 B, where the observer now sees a mixture of the top and bottom colors (e.g., in this case exhibiting an overall gray color due to the size of the particles within the patch on the banknote). In embodiments, and in reference to Fig. 11 C, after removal of the acoustic force, the cores return to their equilibrium configuration, and the observer once again sees the GROVE array in the equilibrium orientation (e.g., as shown as white). In embodiments, the GROVE particles respond to a range of acoustic frequencies of sound, where the range is a within the range of frequencies detectable by human hearing and / or outside of the range of frequencies detectable by human hearing.

[0225] In embodiments, and in reference to Figs. 24A-24D, the one or more core particles have hollow portions (“bubbles”), pores, cavities, and / or places where mass is subtracted. In embodiments, and in reference to Figs. 24A-24D, GROVE particles engineered to include “bubbles,” or hollow spaces, into the one or more core particles confer tunable sound sensitivity and / or acoustic responsiveness (ultrasoundresponsiveness).

[0226] In embodiments, the manipulation and movement of particles using acoustic fields is performed, for example, as described, in Lu et al., “Topographical Manipulation of Microparticles and Cells with Acoustic Microstreaminq,” ACS Appl. Mater. Interfaces, 2017, Vol. 9, 2017: pp. 38870-76; Tian et al., “Generating multifunctional acoustic tweezers in Petri dishes for contactless, precise manipulation of bioparticles, Sci. Adv., Vol. 6, No. 37, 2020: pp 1-11 ; and Jeong et al., “Particle manipulation in a microfluidic channel using acoustic trap,” Biomed Microdevices, Vol. 13, 2011 : pp. 779-88, each of which is hereby incorporated by reference in their entirety.

[0227] In embodiments, GROVE particles described herein have several advantages over existing particles that respond to acoustic force. For example, in embodiments and in reference to the application illustrated in Figs. 11A-C, the core particles within the shell exhibit degrees of freedom of movement irrespective of the shell. In embodiments, the stimulation of GROVE particles does not lead to or require the physical movement of the shell, only the internal core particle.

[0228] In embodiments, different types of acoustic forces are used to manipulate GROVE particles, including but not limited to, acoustic levitation, acoustic tweezers, acoustic streaming, and the use of surface acoustic waves.

[0229] In embodiments, the acoustic forces that lead to movement of GROVE particles to nonequilibrium configurations are acting on the core particle. In embodiments, the acoustic forces are in resonance with the substrate associated with the GROVE particles, acting like a drum to vibrate material associated with the substrate. In embodiments, the acoustic forces are in resonance with the shells of GROVE particles, causing them to vibrate, and thereby causing the core particles to move. In embodiments, the acoustic forces act upon the air surrounding the core particle (e.g., within the shell). In embodiments, the acoustic forces act upon a combination of the air, the core particle itself, the shell, a binder associated with the surface, and / or the surface.

[0230] In embodiments, the use of acoustic forces to move the core particles within the GROVE particles are frequency-dependent. In embodiments, the resonant frequencies depend on one or more of the composition, size, shape, geometry, density, and / or material of the GROVE particle, the shells of the GROVE particles, the core particle of GROVE particle, and / or the substrate associated with GROVE particle.

[0231] In embodiments, the sound frequencies needed to cause GROVE particles to transition from equilibrium to non-equilibrium configurations are in the infrasound range (<20 Hz), or the acoustic or audio sound range [20 Hz to 20,000 Hz (20kHz)], or in the ultrasound range [20 kHz to 200,000,000 Hz (200 MHz)]. In embodiments, the audio sound is in the sub-bass range, with frequencies about or greater than about 10 Hz, about or greater than about 20 Hz, about or greater than about 30 Hz, about or greater than about 40 Hz, about or greater than about 50 Hz, or about or greater than about 60 Hz. In embodiments, the audio sound is in the bass range, with frequencies about or greater than about 70 Hz, about or greater than about 80 Hz, about or greater than about 90 Hz, about or greater than about 100 Hz, about or greater than about 110 Hz, about or greater than about 120 Hz, about or greater than about 130 Hz, about or greater than about140 Hz, about or greater than about 150 Hz, about or greater than about 160 Hz, about or greater than about170 Hz, about or greater than about 180 Hz, about or greater than about 190 Hz, about or greater than about200 Hz, about or greater than about 210 Hz, about or greater than about 220 Hz, about or greater than about230 Hz, about or greater than about 240 Hz, or about or greater than about 250 Hz. In embodiments, the audio sound range is in the low midrange, with frequencies about or greater than about 260 Hz, about or greater than about 280 Hz, about or greater than about 300 Hz, about or greater than about 320 Hz, about or greater than about 340 Hz, about or greater than about 360 Hz, about or greater than about 380 Hz, about or greater than about 400 Hz, about or greater than about 420 Hz, about or greater than about 440 Hz, about or greater than about 460 Hz, or about or greater than about 480 Hz. In embodiments, the audio sound is in the midrange, with frequencies about or greater than about 500 Hz, about or greater than about 750 Hz,about or greater than about 1,000 Hz, about or greater than about 1 ,250 Hz, about or greater than about 1 ,500 Hz, or about or greater than about 1,750 Hz. In embodiments, the audio sound range is in the upper midrange, with frequencies about or greater than about 2,000 Hz, about or greater than about 2,250 Hz, about or greater than about 2,500 Hz, about or greater than about 2,750 Hz, about or greater than about 3,000 Hz, about or greater than about 3,250 Hz, about or greater than about 3,500 Hz, or about or greater than about 3,750 Hz. In embodiments, the audio sound is in the presence range, with frequencies about or greater than about 4,000 Hz, about or greater than about 4,500 Hz, about or greater than about 5,000 Hz, or about or greater than about 5,500 Hz. In embodiments, the audio sound range could be in the brilliance range, with frequencies about or greater than about 6,000 Hz, about or greater than about 8,000 Hz, about or greater than about 10,000 Hz, about or greater than about 12,000 Hz, about or greater than about 14,000 Hz, about or greater than about 16,000 Hz, about or greater than about 18,000 Hz, or about or greater than about 20,000 Hz, including frequencies and frequency ranges therebetween.

[0232] In embodiments, the volume, intensity, and / or magnitude of the sound used to cause GROVE particles to transition from equilibrium to non-equilibrium configurations is faint, moderate, loud, and / or very loud. In embodiments, the sound , intensity, and / or magnitude is about or greater than about 0.25 decibels (dB), about or greater than about 0.50 d B, about or greater than about 0.75 dB, about or greater than about 1 dB, about or greater than about 2 dB, about or greater than about 3 dB, about or greater than about 4 dB, about or greater than about 5 dB, about or greater than about 6 dB, about or greater than about 7 dB, about or greater than about 8 dB, about or greater than about 9 dB, about or greater than about 10 dB, about or greater than about 20 dB, about or greater than about 30 dB, about or greater than about 40 dB, about or greater than about 50 dB, about or greater than about 60 dB, about or greater than about 70 dB, about or greater than about 80 dB, about or greater than about 90 dB, about or greater than about 100 dB, about or greater than about 110 dB, about or greater than about 120 dB, about or greater than about 130 dB, about or greater than about 140 dB, or about or greater than about 150 dB, including volume, intensity, and / or magnitudes and ranges therebetween.

[0233] In embodiments, the duration of sound needed to cause GROVE particles to initiate a transition from equilibrium to non-equilibrium configurations includes sound in over a rapid duration, slow duration, and / or pulsed sound. In embodiments, the duration of sound is about or greater than about 0.01 second (s), about or greater than about 0.02 s, about or greater than about 0.03 s, about or greater than about 0.04 s, about or greater than about 0.05 s, about or greater than about 0.06 s, about or greater than about 0.07 s, about or greater than about 0.08 s, about or greater than about 0.09 s, about or greater than about 0.1 s,about or greater than about 0.15 s, about or greater than about 0.20 s, about or greater than about 0.25 s, about or greater than about 0.30 s, about or greater than about 0.35 s, about or greater than about 0.40 s, about or greater than about 0.45 s, about or greater than about 0.50 s, about or greater than about 0.55 s, about or greater than about 0.60 s, about or greater than about 0.65 s, about or greater than about 0.7 s, or about or greater than about 0.8 s, about or greater than about 0.9 s, about or greater than about 1 s, about or greater than about 1.1 s, about or greater than about 1.2 s, about or greater than about 1.3 s, about or greater than about 1.4 s, about or greater than about 1.5 s, or about or greater than about 2.0 seconds, including durations and duration ranges therebetween.

[0234] In embodiments, the source of the sound used to cause GROVE particles to transition from equilibrium to non-equilibrium configurations includes sounds emanating from a human or non-human animal, from a stationary sound-generating device, a portable sound-generating device, and / or a handheld sound-generating device such as a mobile telephone. In embodiments, the distance between the source of sound and the GROVE particles is about or greater than about 0.0001 m, about or greater than about 0.0005 m, about or greater than about 0.001 m, about or greater than about 0.002 m, about or greater than about 0.003 m, about or greater than about 0.004 m, about or greater than about 0.005 m, about or greater than about 0.006 m, about or greater than about 0.007 m, about or greater than about 0.008 m, about or greater than about 0.009 m, about or greater than about 0.01 m, about or greater than about 0.02 m, about or greater than about 0.03 m, about or greater than about 0.04 m, about or greater than about 0.05 m, about or greater than about 0.06 m, about or greater than about 0.07 m, about or greater than about 0.08 m, about or greater than about 0.09 m, about or greater than about 0.1 m, about or greater than about 0.2 m, about or greater than about 0.3 m, about or greater than about 0.4 m, or about or greater than about 0.5 m, including distances and distance ranges therebetween.

[0235] In embodiments, arrays of combinations of GROVE particles are used to generate digital images. In embodiments, for example as shown in Figs. 12A-15E, GROVE particles are deposited in the shape of an “I” and are surrounded by particles that either do not respond to stimuli for the GROVE particles, or respond to a different stimulus. In embodiments, the application of a force that causes GROVE particles initially at equilibrium to adopt a non-equilibrium configuration will selectively cause a color change in the shape of the “I”. In embodiments, the GROVE particles are arranged in the shape of letters, for example including, A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, or Z, or numerical digits, for example including, 0, 1 , 2, 3, 4, 5, 6, 7, 8, or 9, or symbols, for example including, !, @, #, $, %,A, &, *, (, ), ?, I, <, >, or any other symbol used in the English language character set (or another language).

[0236] In embodiments, the GROVE particles are used to encode or display characters with the character sets for one or more of ASCII, English, Latin, Japanese, Chinese, Korean, Unicode, Unicode Transformation Format - 8 bit (UTF-8), UTF-16, UTF-32, ISO-8859, EBCDIC, Shift JIS, GB2312, GB18030, Big 5, KO18, Coptic, Greek, Cyrillic, Armenian, Arabic, Hebrew, Syriac, Mandaic, Brahmic, Georgian, Mandarin, Cantonese, Bengali, African, Mongolian, CJK, and / or any other known character set.

[0237] In embodiments, one or more components of GROVE particles are synthesized using a Janus Particle (JP) synthesis. In embodiments, there are numerous ways to produce Janus particles, including for example, synthetic approaches as described Su et al. “Janus particles: design, preparation, and biomedical applications”, Materials Today Bio 4, (2019) 100033; Wang et al. “Application of Janus Particles in Point-of- Care Testing”, Biosensors 2022, 12, 689; Claudia Marschelke et al., “Janus particles: from concepts to environmentally friendly materials and sustainable applications,” Colloid and Polymer Science, Vol. 298, 2020: pp. 841-65; Safaie & Ferrier Jr., “Janus nanoparticle synthesis: Overview, recent developments, and applications,” J. Appl. Phys., Vol. 127, No. 170902, 2020; and Saqib et al., “Microfluidic Methods in Janus Particle Synthesis”, Int J Nanomedicine. Vol. 17, 2022: pp. 4355-66, each of which is hereby incorporated by reference in their entirety. In embodiments, one or more components of GROVE particle are manufactured using synthesis incorporating methods including microfluidic synthesis, templated synthesis (e.g., using DNA origami), assembly of the two faces in solution ( / .e., by heterodimerization of particles), polymer-related methods (e.g., such as emulsion polymerization), anisotropic surface modification of individual particles, as well as other methods. In embodiments, microfluidic methods are used to fabricate Janus particles at both the nanoscale and microscale, where the Janus particles can incorporate two or more materials with distinct optical property and then be encapsulated in a shell to produce a GROVE particle. In embodiments, one or more components of GROVE particles are manufactured using one or more methods, or combinations of steps, for example, as described in Bezelya et al., “Microfluidic Devices for Precision Nanoparticle Production,” Micro, Vol. 3, 2023: pp. 822-66; Qu et al., “Fabrication of shape-tunable micromotors based on mass transfer and phase separation,” J. Materi. Sci. (2023), doi.org / 10.1007 / s10853-023-09062-6; Song ef al., “Recent advances in microfluidic fiber-spinning chemistry,” J Polym Sci. 2023: pp. 1-16; Lin et al., “Scalable production of microscopic particles for biological delivery,” Mater. Adv., Vol. 4, 2023: pp. 2885-908; Lui et al., “Recent advances in the microfluidic generation of shape-controllable hydrogel microparticles and their applications”, Green Chemical Engineering, doi.org / 10.1016 / i.gce.2023.02.002; Pilkington et al., “A Microfluidic Platform for the controlled synthesis of architecturally complex liquid crystalline nanoparticles”,” Scientific Reports, Vol. 13, 12684, (2023); Saqib et al., “ Microfluidic Methods in Janus Particle Synthesis,”International Journal of Nanomedicine, Vol. 17, 2022: pp. 4355-4366; Xie et a / ., ’’Microfluidic synthesis as a new route to produce novel functional materials,” Biomicrofluidics, Vol. 16, 041301, (2022); Baah et al., “Microfluidics for particle synthesis from photocrosslinkable materials,” Microfluid Nanofluid, Vol. 12, 2014: pp. 657-62; Agha et al., “A review on microfluidic-assisted nanoparticle synthesis, and their applications using multiscale simulation methods,” Discover Nano, Vol. 18, No. 1 (2023); Gimondi et al., “Microfluidic Devices: A Tool for Nanoparticle Synthesis and Performance Evaluation,” ACS Nano, Vol. 17, 2023: pp. 14205-28; Hao et al., “Microfluidics for Silica Biomaterials Synthesis: Opportunities and Challenges,” Biomaterials Science, Vol. 6, No. 6, 2019: pp. 2218-40; and Kim et al., “Microfluidic preparation of monodisperse polymeric microspheres coated with silica nanoparticles,” Scientific Reports, (2018) Vol. 8, 8525 (2018), the entire contents of each is herein incorporated by reference.

[0238] In embodiments, one or more components of GROVE particles are synthesized as yolk-shell particles. For example, in embodiments and in reference to Fig. 1, the yolk-shell particle comprises an inner core particle 102 to be able to move within the shell 108. In embodiments, the yolk-shell particle is manufactured by producing a particle hollow, or a so-called “rattle” or “nanorattle” or “yolk-shell” or “yolk / shell” or configuration (e.g., analogous to a hard-boiled egg, in which the white protein layer is removed but the yolk and shell are intact). In embodiments, one or more components of GROVE particles are manufactured using one or more methods, or combinations of steps, for example, as described in Si et al., “Research progress of yolk-shell structured nanoparticles and their application in catalysis,” RSC Adv., Vol. 13, No. 3, 2023: 2140-54; Ye et al., “Engineering of Yolk / Core-Shell Structured Nanoreactors for Thermal Hydrogenations,” Small, Vol. 17, No. 9, 2021 : e1906250; Jiao et al., “Design of Magnetic Nanoplatforms for Cancer Theranostics,” Biosensors, Vol. 12, No. 1, 2022: 38; Ziarani et al., “Rational design of yolk— shell nanostructures for drug delivery,” RSC Adv., Vol. 10, No. 50, 2020: pp. 30094-109; Zhou et al., “Hollow microstructural regulation of single-atom catalysts for optimized electrocatalytic performance,” Microstructures, 2022; Vol. 2, 2022: pp. 1-18; Sun X, et al., “A Mini Review on Yolk-Shell Structured Nanocatalysts,” Front. Chem. Vol. 8, 2022: 606044; Wu et al., “The mini-review for synthesis of core@Ag nanocomposite,” Arabian Journal of Chemistry, Vol. 15, No. 1, 2022: 103519; Gai et al., “Advances in coreshell engineering of carbon-based composites for electromagnetic wave absorption.” Nano Research, 2022, Vol. 15, No. 10, 2022: pp. 9410-39; Li and Fan, “Encapsulation methods of sulfur particles for lithium-sulfur batteries: A review,” Energy Storage / Vfeiertats, Vol. 34, 2021 : pp. 107-127; Priebe and Fromm, “Nanorattles or Yolk-Shell Nanoparticles— What Are They, How Are They Made, and What Are They Good For?.” Chemistry, Vol. 21 , No. 10, 2015: pp. 3854-74; Liu et al., “Yolk / shell nanoparticles: new platforms fornanoreactors, drug delivery and lithium-ion batteries Chem. Commun., Vol. 47, 2011: pp. 12578-91 ; Purbia et al., “Yolk / shell nanoparticles: classifications, synthesis, properties, and applications,” Nanoscale, Vol. 7, 2015: pp. 19789-873, the entire contents of each are herein incorporated by reference.

[0239] In embodiments, sacrificial materials are used to construct one or more sacrificial layers as templates or molds for the synthesis of yolk-shell particles. In embodiments, these layers are subsequently removed after the formation of the yolk-shell structure to leave behind a hollow interior or void space within the final particle (e.g., between the shell and the core particle). In embodiments, a variety of materials are used as sacrificial layers in the synthesis of yolk-shell particles, including for example, (a) polymeric materials such as polyvinyl alcohol (PVA), polystyrene (PS), and polyacrylic acid (PAA) used as sacrificial layers due to their ability to form stable films or capsules; (b) surfactants such as cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) used as sacrificial layers due to their ability to form micelles or vesicles; (c) inorganic compounds or inorganic materials such as calcium carbonate (CaCCh), calcium phosphate (Ca3(PO4)2), and sodium bicarbonate (NaHCC ) (e.g., used as sacrificial layers due to their ability to undergo dissolution or decomposition under specific conditions); and (d) organic compounds and / or organic materials such as urea and glucose, owing to the ability to undergo thermal decomposition or chemical reactions. In embodiments, the use of sacrificial layers in the synthesis of yolk-shell particles is performed as described, for example, in Si et al., “Research Progress of yolk-shell structured nanoparticlesa and their application in catalysis”, RSC Adv., 2023, 13, 2140; Guo et al., “Templated Synthesis of Polymer- Based Yolk / Shell Particles with Tunable Morphologies”, Chem. Mater. 2019, 31, 7443-7452; Xu et al., “SelfSacrifice Template Construction of Uniform Yolk-Shell ZnS@C for Superior Alkali-Ion Storage”, Adv. Sci. 2022, 9, 2200247; Sun et al., “A Mini Review of Yolk-Shell Structured Nanocatalysts”, Front. Chem. 2020, 8, 606044; Han et al., “Core-shell to yolk-shell nanostructure transformation by a novel sacrificial template-free strategy”, Chem. Commun. 2013, 49, 11566; Li et al., “Rational design of yolk-shell nanostructures for photocatalysis”, Chem. Soc. Rev. 2019, 48, 1874; and Moon et al., “Yolk-Shell Nanostructures: Syntheses and Applications for Lithium-Ion Battery Anodes,” Nanomaterials 2020, 10, 675, the entire contents of each of which are herein incorporated by reference.

[0240] In embodiments, and in reference to Figs. 27A-27E, various geometries of sacrificial layer and / or shell with respect to the core particle, or “yolk,” are used to form GROVE particles. In embodiments, the sacrificial layer, shell, and / or core particle, are spherical. In embodiments, the sacrificial layer, shell, and / or core particle, are not spherical or conformal (e.g., same shape).

[0241] In embodiments, and in reference to Figs. 33A-33F, an illustrative manufacturing process using a sacrificial layer is shown. In embodiments, core particle material is coated with a material to grow the shell thereon e.g., as shown in Figs. 33A-33B), following by controlled etching of the shell material from inside out, which controls the formation of the void space (e.g., as shown in Figs. 33C). In embodiments, core particle material is coated with a material to grow the shell thereon (e.g., as shown in Figs. 33D-33E), following by controlled etching of the core particle material from outside in, which controls the formation of the void space (e.g., as shown in Figs. 33C). In both instances, in embodiments, etching is controllable based on solubility differences due to lengths of polymerization. In embodiments, the core particle and / or shell is composed of polymeric material and longer polymers will have different solubility than shorter polymers. For example, in embodiments, with respect to the shell, the inside dissolves first, and thus one can control the incubation period, the concentration of solvent, etc., to control the formation of the void space (e.g., as shown in Figs. 33A-33C). Conversely, in embodiments, with respect to the core particle, the outside dissolves first, and thus one can control the incubation period, the concentration of solvent, etc., to control the formation of the void space (e.g., as shown in Figs. 33D-33F).

[0242] In embodiments, a variety of methods are used to manufacture the outer shell, for example, chemical methods, including but not limited to, interfacial polymerization and in situ polymerization; physicochemical methods, including but not limited to, coacervation, layer-by-layer growth, adsorption, solgel encapsulation, and suspension crosslinking; and physicomechanical methods, including but not limited to, lyophilization, spay drying, co-extrusion, fluidized bed spray coating, and phase inversion precipitation.

[0243] In embodiments, the outer shell is inorganic or organic, or a mixture of organic and inorganic substances. In embodiments, non-limiting examples of inorganic materials include alumina, silica, titania, and any other metal oxide, metal sulfide, or metal nitride. In embodiments, shells are composed of mixed metal oxides, mixed metal sulfides, and other mixed metal materials. In embodiments, examples of organic materials include biopolymers (e.g., DNA, RNA, or other nucleic acids, peptides, polypeptides, proteins, and polysaccharides, or any combinations thereof). In embodiments, organic materials include polymers, copolymers, block polymers, and any other form of polymeric organic material. In embodiments, examples of polymeric materials include but are not limited to polystyrene, polyacrylic acid, Poly Lactic-co-Glycolic Acid, Poly vinyl alcohol, Pluronic, Polyvinylpyrrolidone, Carbopol, alginate, hyaluronic Acid, poly(N-isopropyl acrylamide), poly (N-alkyl acrylamides), polyAcrylamide / polyAcrylic Acid copolymers, Carbopol, Pluronic 127, poly(Oligo Ethyleneglycol Methacrylate), polycaprolactone, gelatin metal-organic frameworks (MOFs), and covalent organic frameworks.

[0244] In embodiments, the outer shell is porous or non-porous. Alternatively, in embodiments, the shell is porous during synthesis (e.g., removed as a sacrificial layer), and then converted to a non-porous state. For example, in embodiments, with respect to silica-based shells, numerous methods exist to convert a porous silica shell to a non-porous silica shell. In embodiments, silica-based shell conversion for the manufacture of GROVE particles is performed, for example, as described in Mochizuki et al., “Development of Non-Porous Silica Nanoparticles towards Cancer Photo-Theranostics”, Biomedicines 2021 , 9, 73; Zhou et al., “Design and pharmaceutical applications of porous particles”, RSC Adv. 2017, 7, 39490; Maiti et al., “Advancements in organic and inorganic shell materials for the preparation of microencapsulated phase change materials for thermal energy storage applications”, RSC Sustainability 2023, 1 , 665; and Tang et al., “Nonporous silica nanoparticles for nanomedicine application”, Nano Today 2013, 8, 290-312, the entire contents of each of which are herein incorporated by reference.

[0245] In embodiments, the outer shell is partially or fully transparent. In embodiments, such a shell is advantageous because the transparency of the shell improves the penetration of light into the particle and reduces scattering. In embodiments, there are various methods for making optically transparent shells for core-shell nanoparticles, depending on the type of shell material and the desired properties of the final particles. For example, in embodiments, the method of manufacturing the shell includes (1) layer-by-layer assembly: this method involves sequentially depositing alternating layers of oppositely charged polymers or other materials onto the surface of the nanoparticle core. In embodiments, the resulting shell is made to be optically transparent by choosing materials with high transparency in the desired wavelength range. In embodiments, the method of manufacturing the shell includes (2) sol-gel methods which involve hydrolyzing and condensing a precursor material in solution around the nanoparticle core, resulting in the formation of a porous network that is annealed to create a solid, transparent shell. In embodiments, common precursor materials include metal alkoxides and silicon alkoxides. In embodiments, the method of manufacturing the shell includes (3) emulsion-based methods, where the core-shell nanoparticles are formed by emulsifying a solution of the core material in a solution of the shell material, followed by polymerization or crosslinking of the shell material to form a solid shell around the core (e.g., as shown in Figs. 26A-26B). In embodiments, careful control of the emulsion conditions, such as the surfactant type and concentration, is done to create optically transparent shells. In embodiments, the method of manufacturing the shell includes (4) gas-phase methods, for example, involving evaporating a precursor material in a high-temperature gas-phase reactor and depositing the resulting vapor onto the nanoparticle core. In embodiments, controlling the reaction conditions, such as temperature and pressure, is done to create a uniform, optically transparent shell.

[0246] In embodiments, optically transparent shells are synthesized, for example, as in Deng et al., ‘‘Transparent, Thermally Stable and Mechanically Robust Superhydrophobic Surfaces Made from Porous Silica Capsules”, Adv. Mater, 2011 , 23, 2962; Ernawati et al, “Hollow Silica as an Optically Transparent and Thermally Insulating Polymer Additive”, Langmuir 2016, 32, 338-345; Liang et al, “Nature of Electromagnetic- Transparent SiO2Shell in Hybrid Nanostructure Enhancing Electromagnetic Attenuation”, J. Phys. Chem. C 2016, 12,967-12,973; Dolatyari et al, “Transparent Display using a guasi-array of Si-SiO2 Core-Shell Nanoparticles”, Scientfic Reports 2019, 9:2293; and Sangermano et al, “Synthesis of Au@SiO2 Core / Shell Nanoparticles and their Dispersion into an Acrylic Photocurable Formulation: Film Preparation and Characterization”, Macromol. Chem. Phys. 2008, 209, 2343-2348, the entire contents of each of which are herein incorporated by reference.

[0247] In embodiments, an additive, reagent, layer, and / or surface modification is incorporated into the GROVE particle to reduce friction between the one or more particle cores inside the GROVE particle and the inner surface of the outer shell. In embodiments, this enables greater freedom of movement of the core particle within the shell. In embodiments, the element(s) incorporated in the GROVE particle to reduce friction are associated with the shell, with the core particle, with a surface of the interior volume of the shell, and / or combinations of each surface. In embodiments, the elements used to reduce friction include but are not limited to graphene, graphite and other carbon materials, polytetrafluoroethylene, molybdenum disulfide, silicon-containing molecules and polymers, polyethylene glycol, water, non-aqueous solvents, mineral oil lubricants, synthetic lubricants, nanoparticles with a high degree of hardness, and components of grease.

[0248] In embodiments, the core particle possesses nanostructural or microstructural features designed to minimize contact with the inner surface of the shell. In embodiments, these features fall broadly into the category of surface roughness, and include bumps, detents, particles, or other geometric or non-geometric features on the outer surface of the core particle. In embodiments, the inner surface of the shell possesses nanostructural or microstructural features designed to minimize contact with the core particle. These features fall broadly into the category of surface roughness, and could be bumps, detents, particles, or other geometric or non-geometric features on the inner surface of the shell e.g., “lobes” on the surface as shown in Fig. 37 and in Figs. 39A-F).

[0249] In aspects, described herein are photonic devices incorporating arrangements (e.g., arrays) of GROVE particles as an embedded feature, for example as described in Gangwar ef al., “Recent Progress in Photonic Crystal Devices and Their ApDlications: A Review,” (2023) Photonics, Vol. 10, No. 1199, and Zhaoet al., “From silica colloidal particles to photonic crystals: Progress in fabrication and application of structurally colored materials,” (2023) Textile Research Journal, Vol. 93, no. 11-12, pp. 2287-93, the entire contents of each being incorporated by reference.

[0250] In aspects, described herein are microlens and specialty films incorporating arrangements (e.g., arrays) of GROVE particles as an embedded feature, for example as described in Chen et al., “Naked-Eye 3D Display Based on Microlens Array Using Combined Micro-Nano Imprint and UV offset Printing Methods,” (2020) Molecules, Vol. 25, No. 9, the contents of which are incorporated by reference. For example, in embodiments, the lens is a linear and / or circular Fresnel lens. In embodiments, the Fresnel lens is a microstructure composed of facets that bend or reflect light like a thick lens. In embodiments, the lens is made to either focus or spread light. In embodiments, the GROVE particles are positioned on the lens, in the plane with the lens, or behind the lens. In embodiments, the positioning of GROVE particles in the focal point of a lens allows for magnification, and potentially a more intense or more interesting effect. In embodiments, the GROVE particle lens amplifies one or more optical properties (e.g., like magnifying glass). In embodiments, use of a lens saves on material, by only requiring GROVE in the wells, divots, etc., surrounding a lens, rather than necessitating covering an entire surface area.Methods of Manufacturing Gravity-Responsive Optically-Variable Encapsulated (GROVE) Particles

[0251] The present disclosure provides, in embodiments, methods of manufacturing GROVE particles. In embodiments, the GROVE particles satisfy a few structural and functional criteria: 1) it includes physical properties (e.g., a core particle comprising at least two materials of distinct density, at least two optically active agents, and an outer shell that holds the core particle inside) that enables movement within the shell, and 2) where the optical properties change as a function of movement after stimulation (e.g., mechanical perturbation, sound, magnetic field, etc.). In embodiments, all methods relating to the manufacture of GROVE particles relate to GROVE particles.

[0252] In embodiments, methods of manufacturing the GROVE particles includes a number of fabrication techniques used to generate particles on size scales from millimeters through microns down to nanometer dimensions. In embodiments, these methods include in non-limiting examples: chemical or physical methods including but not limited to self-assembly, adsorption, coacervation, and / or mixing; polymerization, extrusion, and / or manipulation of polymers.

[0253] In embodiments, chemical techniques such as coacervation are used to generate the particles. Coacervation, in embodiments, is a process in which two or more polymers are mixed together in a solutionand undergo phase separation to form two distinct phases. In embodiments, one phase is rich in polymer, while the other phase is depleted in polymer and mostly contains solvent. Coacervation, in embodiments, is used to produce microspheres or microcapsules, which are small, spherical particles that can be used for drug delivery, encapsulation, and other applications. During coacervation, in embodiments, the polymers undergo a process of self-assembly, where they form complex structures through non-covalent interactions such as electrostatic forces, hydrogen bonding, and van der Waals forces. In embodiments, generating the GROVE particles includes a combination of coacervation to make the core particle and a second method for generating the shell.

[0254] In embodiments, generating GROVE particles includes the chemical method of click chemistry, a class of simple, atom-economy reactions commonly used for joining two molecular entities of choice. Click reactions, in embodiments, occur in a single vessel, are not sensitive to water, generate minimal byproducts, and are "spring-loaded" — characterized by a high thermodynamic driving force that quickly and irreversibly drives the reaction to high yield of a single reaction product, with high reaction specificity (in some cases, with both regio- and stereo-specificity). In embodiments, generating particles for GROVE particles includes other chemical methods well-known (especially in life sciences) for joining two entities together including in non-limiting examples, streptavidin-biotin coupling, maleimide-based reactions, and carbodiimide-based reactions.

[0255] In embodiments, at least one layer of the shell comprises performing one or more of mesoporous material synthesis, soft-templating, calcination, and / or extraction. For example, in embodiments, GROVE particle outer shell is produced using a hollow yolk-shell particle method (e.g, as illustrated in Figs. 23A- 23E) including: A) producing a silica core, B) coating the silica core with polystyrene (PSt) to form a polystyrene layer around the silica core (e.g, a dissolution layer); C) forming a silica (SiOz) shell around the PSt layer; D) calcination at high temperature (e.g, 500°C for 4 hr.) to create a void space between the silica shell and core; and E) etching with NH3. In embodiments, the method can include dispersing thermally responsive polymers within the void space or cavity of the hollow yolk-shell particles. In embodiments, the method includes applying one or more protective coating(s) to the core prior, for example in place of the PSt layer or in addition to. In embodiments, the method can include a hardening step after etching to close or seal any pores in the shell layer.

[0256] In embodiments, the synthesis of GROVE particles is via the formation of Janus particles. In embodiments, Janus particles are a type of particle characterized by having two distinct regions or "faces"with different physical and / or chemical properties. In embodiments, the two faces of Janus particles can have different surface chemistry, size, shape, or polarity, which makes them useful in a variety of applications, including drug delivery, catalysis, and self-assembly. In embodiments, Janus particles are attractive, because they are a unique class of anisotropic materials that are simple, but for which all the structural parameters can be completely controlled. In embodiments, Janus particle-based GROVE particles are synthesized at large scale, and under surfactant-free conditions, for example, as described in WALTHER and MULLER, “Janus Particles: Synthesis, Self-Assembly, Physical Properties, and Applications,” Chem. Rev., Vol. 113, 2013: pp. 5194-5261; VOGEL etal. “Advances in Colloidal Assembly: The Design of Structure and Hierarchy in Two and Three Dimensions,” Chem. Rev., Vol. 115, 2015: pp. 6265-6311 ; TANG et al., “Large Scale Synthesis of Janus Submicrometer Sized Colloids by Seeded Emulsion Polymerization, ” Macromolecules, Vol. 43, 2010: pp. 5114-5120; and PHAM et al., “Synthesis of Polymeric Janus Nanoparticles and Their Application in Surf actant- Free Emulsion Polymerizations,” Polym. Chem. Vol. 6, 2015: pp. 426-435, each of which is hereby incorporated by reference in their entirety.

[0257] In embodiments, and in reference to Figs. 34A-34G, illustrative manufacturing processes for producing JP-based core particles using microfluidics is shown. For example, in embodiments, a core particle formed upstream in a first microfluidic channel e.g., as illustrated at Figs. 34A and 34D) is flowed in a first direction. In embodiments, the directionality of the particles is controlled, for example, using a magnet. In embodiments, a single droplet of a third material e.g., as shown in Figs. 34B-34C) are deposited into each core particle (e.g., as shown in Figs. 34E-34G), where each core particle has equivalent number of droplets and in substantially in the same place. In embodiments, the droplets are used to embed or imbue a variety of features, optical properties, changes in density, include hollow / bubbles, etc. In embodiments, the method comprises exposure to or application of UV radiation, light, thermal energy, flowing a gradient of a catalyst into the microfluidic chamber, etc., to polymerize, cure, or otherwise harden the particles within the microfluidic chamber (e.g., as shown in Fig. 34G and downstream).

[0258] In embodiments, and in reference to Figs. 30A-30B, GROVE particles have a gradient of colors and / or density, for example as shown by shading. In embodiments, JP-based core particles are comprised of a gradient in color / density, where there are strict demarcations in color, density, or material (e.g., as shown in Fig. 30A), or a constant, smooth transition in color, density, or material (e.g., as shown in Fig. 30B).

[0259] In embodiments, Figs. 20A-20G depict a series of side-view representations of synthetic routes of producing GROVE particles. Fig. 20A represents a prototypical Janus particle. Fig. 20B represents aJanus particle coated with a coating material. Fig. 20C represents an encapsulated yolk-shell particle with a porous shell. Fig. 20D represents an encapsulated Janus particle in a yolk-shell configuration. Fig. 20E represents an encapsulated, coated Janus particle in a yolk-shell configuration. Fig. 20F represents a Janus particle encapsulated in a porous shell, in a yolk-shell configuration. Fig. 20G represents a coated Janus particle encapsulated in a porous shell, in a yolk-shell configuration. The Janus core particle is made before incorporation into a shell, or a particle encapsulated within a shell is converted into a Janus particle.

[0260] In embodiments, a Janus particle of Fig. 20A e.g., corresponding substantially to the core particle 400 of Fig. 1) is coated to yield the particle of Fig. 20B, which is then be converted to the GROVE particles of Fig. 20D, Fig. 20E, Fig. 20F, or Fig. 20G. In embodiments, several approaches useful for manufacturing GROVE particles are re described, for example, in Ziarini et al., “Rational design of volk-shell nanostructures for drug delivery,” RSCAdv., 2020, Vol. 10, 30094, which is herein incorporated by reference in its entirety.

[0261] In embodiments, and in reference to Figs. 32A-32F, micelle-based nanoparticle construction is sued to generate GROVE particles. For example, in embodiments, a micelle nanoparticle is formed {e.g., as shown in Fig. 32A) with a core particle material encapsulated therein (e.g., as shown in Fig. 32B), followed by growing a shell around the micelle material. In embodiments, this process is performed with precursor material, which is formed in situ into the core particle (e.g., using gold dust / atoms in a micelle to form gold particle, for example, as illustrated in Figs. 32D-32F).

[0262] In embodiments, the core of GROVE particles (e.g., such as those illustrated in Figs. 22A-22F) are manufactured using microfluidics, evaporation, deposition, and / or methods similar to those described herein. In embodiments, and in reference to Fig. 22A, the core comprises a darker optical material (e.g., shown in black) and a lighter optical material comprising particles incorporated into a transparent polymer. In embodiments, and in reference to Fig. 22B, the optical properties of the lighter optical material derives from a single (larger) particle. In embodiments, and in reference to Fig. 22C, the lighter optical material (e.g., which is of greater density than the darker optical material on the top of the core particle), includes colored particles added to a colored polymer. In embodiments, and in reference to Fig. 22D, the core particle comprises a first lighter optical material (e.g., gray particles) associated with the top part of a particle, and a second, denser optical material (e.g., white particles) associated with the bottom of a particle. In embodiments, and in reference to Fig. 22E, the core particle comprises four different materials, one hemisphere of a first optical material (e.g., shown as a dark hemisphere), a second optical material (e.g., cross-hatched), a third opticalmaterial (e.g., shown in white), and a fourth, higher density material (e.g., shown as a smaller gray particle), the position of which dictates the position of the core at equilibrium. In embodiments, and in reference to Fig. 22F, the core particle is non-spherical, with a hemispherical denser bottom (e.g., shown as black), a less dense optical material (e.g., shown as white) and a material in between the two optical materials (e.g., shown as gray).

[0263] In embodiments, GROVE particles are manufactured using latex polymer particles, for example, using MAGSPHERE (micron-sized latex polymer particle), having approximately 15 pm diameter particle size. In embodiments, GROVE particles are manufactured using, in non-limiting examples, one or more of polystyrene latex polymer, carboxylated latex polymer, aminated latex polymer, colored polystyrene polymer (dye-infused and / or pigment-infused), colored polystyrene-based carboxylated latex polymer (dye-infused and / or pigment-infused), fluorescent polystyrene-based polymers, fluorescent polystyrene-based carboxylated latex polymers, fluorescent aminated polystyrene-based polymer, surfactant-free polystyrene, carboxylated surfactant-free polymer, polymethyl methacrylate (PMMA) latex polymer, and divinylbenzene (DVB)-crosslinked polystyrene latex polymer.

[0264] In embodiments, GROVE particles are incorporated into and / or with one or more substrate materials, as described herein. In embodiments, the one or more substrate materials is porous and / or hollow. In embodiments, methods of manufacturing include doping the one or more substrate materials with a denser material. In embodiments, the denser material is infused, embedded, or otherwise placed into a bottom portion of the particle. In embodiments, generating the particle includes joining at least two substrate materials, wherein the two substrate materials differ in density.

[0265] In embodiments, the one or more substrate materials is transparent to at least a portion of the visible electromagnetic (EM) spectrum. In embodiments, the one or more transparent substrate materials includes glass, quartz, plastic, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers (TPE), acrylonitrile butadiene styrene (ABS), epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer (COC) cyclic olefin polymer (COP), poly dimethyl siloxane (PDMS), poly ether ester ketone (PEEK), polyetherimide (ULTEM) and / or nylon.

[0266] In embodiments, the one or more substrate materials has a thickness of about or at least about 50 nm, is about or at least about 100 nm, is about or at least about 500 nm, about or at least about 1 pm, isabout or at least about 10 m, is about or at least about 100 pm, about or at least about 1 mm, about or at least about 5 mm, or about or at least about 10 mm, including thicknesses therebetween.

[0267] In embodiments, methods of manufacturing GROVE particles includes disposing one or more optically active agents onto and / or into the one or more materials that comprise the GROVE particles. In embodiments, the one or more materials is porous, where the one or more optically active agents is disposed into the pores of the material. In embodiments, the one or more optically active agents is applied to one or more surfaces of the GROVE particles. In embodiments, the one or more optically active agents comprise a color in the visible electromagnetic spectrum comprising an extinction, reflection, or scattering at a wavelength from about or at least about 350 nm to about or at least about 800 nm. In embodiments, the color is one or more of white, black, red, orange, yellow, green, blue, indigo, and / or violet.

[0268] The one of more optically active agents for manufacturing GROVE particles herein, in embodiments, include any optically active agents, including dyes, pigments (organic and / or inorganic), nanoparticles, fluorescent materials, metal and / or metallic materials, plasmonic materials, etc.

[0269] In embodiments, a transparent top substrate is added, e.g., as shown in Figs. 8D-8E and 8H. In embodiments, contact is made between the top / bottom substrates and one or more posts, walls, or other structures which holds the substrates in place around the GROVE particles. In embodiments, the substrate is held in place by glue, adhesive, pressure, adhesion, or by any other means by which two materials are fastened. In embodiments, the substrate is composed of a material that is transparent to at least a portion of the visible EM spectrum (e.g., transparent to light in the range of 350 nm to 800 nm), including in non-limiting examples, glass, plastic, quartz, sapphire, gel, etc. In embodiments, the top substrate includes a variety of thicknesses, as described herein. In embodiments, the top substrate is planar or non-planar, and adopts a variety of shapes, e.g., such as conforming to the surface of an object the GROVE particles are intended to cover.

[0270] In embodiments, methods of manufacturing GROVE particles herein include applying the GROVE particles to a surface, for example to the bottom surface of a well or plate.

[0271] Methods for immobilizing binding molecules onto surfaces and / or applying GROVE particles to surfaces include, for example, a variety of surface chemical treatment and attachment chemistries, as described in Wang & Jin, 2004; Vashist, 2012; Vashist, et al., 2014; U.S. Patent No. 7,577,470; and U.S. Patent No. 7,813,780.

[0272] Methods of manufacturing GROVE particles herein, in embodiments, include formulating the GROVE particles into a foil, film, thin plastic, and / or paper substrate, material, and / or surface. In embodiments, the foil, film, thin plastic, and / or paper substrate, material, and / or surface is suitable to be affixed to, or embedded in, an object.

[0273] Methods of manufacturing GROVE particles herein, in embodiments, include formulating the GROVE particles into a fiber, thread, yarn, and / or twine substrate, material, and / or surface. In embodiments, the fiber, thread, yarn, and / or twine substrate, material, and / or surface is suitable to be woven into an article of clothing, a cloth, and / or a tarp.

[0274] Methods of manufacturing GROVE particles herein, in embodiments, include formulating the GROVE particles into a fluid, suspension, ink, liquid film, and / or adhesive substrate, material, and / or surface. In embodiments, the fluid, suspension, ink, liquid film, and / or adhesive substrate, material, and / or surface is suitable to be applied to an object.Methods of Using Gravity Responsive Optically Variable Encapsulated (GROVE) Particles

[0275] The present disclosure provides, in embodiments, method of using GROVE particles in instances to imbue a material or object with optical property-changing effects. In embodiments, the method of use is for authenticating a material (e.g., using GROVE particles to confer specific optical properties to an object). In embodiments, the method includes providing a formulation of GROVE particles, as described herein, wherein the formulation comprises a fluid, suspension, ink, liquid film, adhesive, and / or material thereof; a foil, film, thin plastic, paper, and / or material thereof; or a fiber, thread, yarn, twine, and / or material thereof.

[0276] In embodiments, the material comprises providing a formulation of gravity-responsive optically- variable encapsulated (GROVE) particles, wherein the formulation comprises a fluid, suspension, ink, liquid film, adhesive, and / or material thereof; a foil, film, thin plastic, paper, and / or material thereof; or a fiber, thread, yarn, twine, and / or material thereof. In embodiments, methods are useful for authentication of an object, a material, a substance and / or a surface. In embodiments, the method comprises (a) tagging or otherwise marking an object, a material, a substance, and / or a surface with a composition or formulation of GROVE particles, and (b) detecting, observing, or measuring a change in optical properties as a function of applying a force. In embodiments, tagging or otherwise marking further comprises arranging, spraying, gluing, printing, and / or weaving the GROVE particles into the shape of characters comprising letters, numerical digits, and / or symbols.

[0277] In embodiments, the method of authenticating an object using a gravity-responsive optically- variable encapsulated (GROVE) particles comprises providing an object comprising GROVE particles, or comprising a composition of GROVE particles, wherein the object has an initial optical state, applying a force to the object and / or the GROVE particles, to cause a movement in the GROVE particles which elicits the object to present a change in one or more optical properties from the initial optical state, and detecting the change in the one or more optical properties as a function of the application of the force.

[0278] In embodiments, the method further comprises tagging, applying, arranging, spraying, gluing, and / or weaving the GROVE particles (or a formulation thereof) onto the object, optionally into the shape of characters comprising letters, numerical digits, symbols, and / or images.

[0279] In embodiments, the tagging further comprises arranging, spraying, gluing, and / or weaving the GROVE particles into a material. In embodiments, the GROVE particles are arranging into the shape of characters comprising letters, numerical digits, and / or symbols. In embodiments, the shape of the characters is observable as a function of applying a force. In embodiments, the force comprises one or more of gravity, a mechanical force, an acoustic force, a magnetic force, and an electrical field. For example, in embodiments and in reference to Figs. 11A-11C, GROVE particles (e.g., on the micron and / or nanometer scall) are embedded into an object (e.g., such as a banknote, paper currency, document, etc.) where the GROVE particles change color upon exposure to a particular frequency or range of frequencies of sound.

[0280] In embodiments, authentication comprises object including paper, plastic, glass, metal, fabric, wood, a window, documentation, an electronic device, a computer chip, construction materials, human or animal tissue or skin, leather, luxury goods, high-value goods, hardware, computer hardware, and / or mobile phones. In embodiments, the object comprises paper currency, bank notes, checks, and / or money orders. In embodiments, the object comprises documentation, tax stamps, passports, identification, government-issued documents and permits, and driver’s license.

[0281] In embodiments, the object comprises a surface that has one or more regions that are substantially planar, non-planar, convex, concave, or without a well-defined shape. In embodiments, the GROVE particles and / or GROVE particle film are located on an interior surface of the object and / or on an exterior surface of the object.

[0282] In embodiments, the force applied comprises one or more of a mechanical force (shaking, agitation, jerking, tilting), gravity (reorienting the position relative to gravity), acoustic force (sound), magneticforce (magnetic field / flux), and an electrical field. In embodiments, applying the force comprises moving the object relative to the direction of gravity and / or applying a magnetic field.

[0283] In embodiments, the change in the optical property comprises a change in one or more color in the visible electromagnetic (EM) spectrum comprising an absorption, emission, extinction, reflection, scattering, and / or interference properties at a wavelength, optionally from about 350 nm to about 800 nm. In embodiments, the one or more color comprises one or more of white, black, red, orange, yellow, green, blue, indigo, violet, or a color shade or hue therebetween.

[0284] In embodiments, the shape of the characters is observable as a function of applying a force. In embodiments, the characters are from one or more of ASCII, English, Latin, Japanese, Chinese, Korean, Unicode, Unicode Transformation Format - 8 bit (UTF-8), UTF-16, UTF-32, ISO-8859, EBCDIC, Shift JIS, GB2312, GB18030, Big 5, KO18, Coptic, Greek, Cyrillic, Armenian, Arabic, Hebrew, Syriac, Mandaic, Brahmic, Georgian, Mandarin, Cantonese, Bengali, African, Mongolian, CJK, and / or any other known character set. In embodiments, the GROVE particles are applied as a homogenous patch that lacks any specifying characters and changes optical properties in the shape of the patch (e.g., a square, rectangle, circle, triangle, star, pentagon, octagon, etc.). In embodiments, the change in the optical property that is detected is substantially in the pattern of the particles.

[0285] In embodiments, one or more of the colors associated with the GROVE particles and / or GROVE film substantially corresponds with a color of the object to be authenticated.

[0286] In embodiments, the change in optical property is detectable by human vision, and / or wherein the change in optical property is not detectable by human vision. In embodiments, the change in optical property comprises one or more covert features. In embodiments, the one or more covert features comprises a change in optical property and / or a detectable signal as a function of the application of a force, optionally wherein the one or more covert features are not detectable by human vision. In embodiments, the one or more covert features are incorporated into a first side of the core particle (JP), or two or more sides of the core particle (JP). For example, in embodiments, a covert feature is a fluorescent feature, where the GROVE particle exhibits emission / fluorescence due to the addition of a fluorophore. In embodiments, if each side of a core particle has the feature, e.g., even distribution of fluorophore, the particle will always exhibit glowing. In embodiments, if the fluorophore is added to only a single portion, the fluorescence is observable only when the particle is moved to a specific orientation. In embodiments, the cover feature is add into shell and / or the core particle.

[0287] In embodiments, detecting the change in the optical property comprises using one or more of a camera, spectrometer, filter, window, grating, beam splitter, polarizer, collimator, birefringent element, prism, bandpass filter, aperture, or lens to detect an optical signal emanating from the object. In embodiments, the detecting comprises measuring, observing, and / or registering an optical signal generated by the GROVE particles via one or more of an radio frequency (RF) reader, barcode scanner, human vision, and camera.

[0288] In embodiments, the method further comprising reading the tagging. Reading the tagging includes, in embodiments, measuring, observing, and / or registering an optical signal generated by the GROVE particles. This is performed, in embodiments, via one or more of an radio frequency (RF) reader, barcode scanner (including a QR code scanner or equivalent), human vision, and / or a camera. In embodiments, the optical property change from the GROVE particles is observable by human vision. In embodiments, the optical property change resembles that of a barcode and / or QR code and is readable using a barcode scanner or a camera. In embodiments, the optical property change presents in a complicated pattern and / or message that is configured to be read by a camera with sufficient zoom to adequately discriminate the pattern and / or message. In embodiments, the detecting is performed as a function of the movement and as a function of time e.g., were an optical signal / function as a function of time is observable from the optical change in response to a stimuli).

[0289] In embodiments, authenticating further comprising comparing the change in the one or more optical properties to a standard signal, wherein the comparison to the standard signal verifies the authenticity of the object. In embodiments, the method further comprising determining the authenticity of the material and / or object by comparing the reading to that of a standard. In embodiments, the standard is a comparison or key that holds the correct optical signal (e.g., color change, shape, character, pattern, message, or another feature) to measure against in determining that the optical property change that is observed is accurate.

[0290] In aspects, described herein is an overt authentication feature comprising one or more GROVE particles. In embodiments, the GROVE particles are a component of the overt authentication feature.

[0291] In aspects, described herein is a gravity-responsive optically-variable encapsulated (GROVE) particle, wherein the GROVE particle is as substantially shown in any one of Figs. 1, 2A-2E, 4A-4L, 5A-5F, 6A-6G, 7A-7F, 20A-20G, 22A-22F, 24A-24D, 27A-27E, 28A-28E, 29A-29E, 30A-30B, 33A-33F, 34A-34G, 37, 38, 39, 40A-40D, 41A-41B, 42A-42D, 43A-43C, 44A-44C.Compositions

[0292] In embodiments, described herein are compositions comprising GROVE particles. In embodiments, the composition includes GROVE particles formulated into a foil, film, thin plastic, and / or paper substrate, material, and / or surface. In such embodiments, the GROVE particles are present in a number of GROVE particles per area, for example, at about or at least about 106GROVE particles / mm2, about or at least about 105GROVE particles / mm2, about or at least about 104GROVE particles / mm2, about or at least about 1,000 GROVE particles / mm2, about or at least about 100 GROVE particles / mm2, about or at least about 50 GROVE particles / mm2, about or at least about 10 GROVE particles / mm2, about or at least about 5 GROVE particles / mm2, about or at least about 1 GROVE particles / mm2or fewer, including ranges and amounts therein.

[0293] In embodiments, the composition includes GROVE particles formulated into a fiber, thread, yarn, and / or twine substrate, material, and / or surface. In such embodiments, the GROVE particles are present in a number of particles per distance in length, for example, at about or at least about 50,000 GROVE particles / mm, about or at least about 10,000 GROVE particles / mm, about or at least about 1 ,000 GROVE particles / mm, about or at least about 500 GROVE particles / mm, about or at least about 100 GROVE particles / mm, about or at least about 50 GROVE particles / mm, about or at least about 10 GROVE particles / mm, about or at least about 5 GROVE particles / mm, about or at least about 1 GROVE particles / mm, about or at least about 0.5 GROVE particles / mm, or about or at least about 0.1 GROVE particles / mm, or fewer, including ranges and amounts therein.

[0294] In embodiments, the composition includes GROVE particles formulated into a fluid, suspension, ink, liquid film, and / or adhesive substrate, material, and / or surface. In such embodiments, the GROVE particles are present in mass per volume, for example at about or at least about 0.001 mg / mL, about or at least about 0.01 mg / mL, about or at least about 0.1 mg / mL, about or at least about 1 .0 mg / mL, about or at least about 10 mg / mL, about or at least about 50 mg / mL, about or at least about 100 mg / mL, about or at least about 150 mg / mL, about or at least about 200 mg / mL, about or at least about 250 mg / mL, about or at least about 300 mg / mL, about or at least about 350 mg / mL, or about or at least about 400 mg / mL or more., including concentrations and concentration ranges therebetween.

[0295] Alternatively, described herein, in embodiments, are objects which have GROVE particles applied to them. In embodiments, the composition includes a consumer good with GROVE particlesincorporated therein, for example, packaging with GROVE particles incorporated therein, fabrics with GROVE particles woven therein, paper / foil products coated with GROVE particles, etc.

[0296] In embodiments, the composition includes an object imbued with GROVE particles as a security measure, for example for authentication of paper currency, authenticity markers of documents, and the like. In embodiments, the composition includes cosmetics, tattoos, and / or semi-permanent makeup imbued with GROVE particles, for example GROVE particles that are about or at least about 10 pm and smaller, which are used to confer color-changing properties to the cosmetics, tattoos, and / or semi-permanent makeup. In embodiments, the composition includes GROVE particles as obscurants, for example, with GROVE particles “sandwiched” between two or more substrates (e.g., glass) for use in windows, mirrors, and / or doors. In embodiments, the composition is a fluid or liquid that includes GROVE particles as obscurants, for example, where stimuli applied to the fluid or liquid changes the optical properties (e.g., light transmissibility or color) of the fluid or liquid charges.

[0297] Accordingly, the present disclosure provides, in part, color-changing film compositions comprising (i) one or more color-changing, GROVE particle, (ii) substrates upon which the GROVE particles rest, and (iii) optically transparent surfaces above the GROVE particles. In embodiments, the substrate includes any described herein.

[0298] In embodiments, disclosed herein is a method of establishing the authenticity of an object of value comprising (i) associating the color-changing, GROVE film with an object, (ii) applying a stimuli to the object (or within close proximity to the object) to influence the movement of the core particle within the GROVE particles in the film, where (iii) the effect of the stimuli and the movement within the GROVE particles leads to a change in optical property (e.g., color), and (iv) detecting the change in optical property (e.g., color). In embodiments, the object includes any described herein.Kits

[0299] In embodiments, the compositions (e.g., GROVE particle paper / foil, fluid, solution, suspension, fiber, thread, etc.) of the present disclosure are assembled into a kit. In embodiments, the kit comprises GROVE particles in one or more formulations described herein for application to one or more objects.

[0300] The kit described herein may include one or more containers housing components for performing the methods described herein and optionally instructions for use. Any of the kits described herein may further comprise components needed for performing the manufacturing methods described herein. Each componentof the kits, where applicable, may be provided in liquid form (e.g., in solution, suspension, ink, paint, etc.) or in solid form, (e.g., dry powders, paper, foil, fiber, etc.). In embodiments, some of the components are reconstitutable or otherwise processible (e.g., GROVE particles in powder / granule form that can be resuspended in one or more solvents / fluids to be applied to an object), for example, by the addition of a suitable solvent or other species (for example, water, ink, or paint), which may or may not be provided with the kit.

[0301] In embodiments, the kits may optionally include instructions and / or promotion for use of the components provided. As used herein, "instructions" can define a component of instruction and / or promotion, and typically involve written instructions on or associated with packaging of the disclosure. Instructions also can include any oral or electronic instructions provided in any manner such that a user will clearly recognize that the instructions are to be associated with the kit, for example, audiovisual (e.g., videotape, DVD, etc.), Internet, and / or web-based communications, etc. As used herein, "promoted" includes all methods of doing business including methods of education, engineering instruction, scientific inquiry, discovery or development, academic research, manufacturing, chemical, cosmetic, and pharmaceutical industry activity including sales, and any advertising or other promotional activity including written, oral, and electronic communication of any form, associated with the disclosure. Additionally, the kits may include other components depending on the specific application, as described herein.

[0302] The kits may have a variety of forms, such as a blister pouch, a shrink wrapped pouch, a vacuum sealable pouch, a sealable thermoformed tray, or a similar pouch or tray form, with the accessories loosely packed within the pouch, one or more tubes, containers, a box, or a bag.

[0303] Without further elaboration, it is believed that one skilled in the art can, based on the above description, utilize the present disclosure to its fullest extent. The following specific embodiments are, therefore, to be construed as merely illustrative, and not limiting of the remainder of the disclosure in anyway whatsoever.EXAMPLESExample 1: Effect of gravity on a Janus particle

[0304] Janus particles were created by applying a single coat of silver (Ag) paint (water-based silver conductive paint) onto one hemisphere of a clear, 1.55 mm diameter polystyrene sphere (COSPHERIC). The resulting Janus particle appeared clear on one hemisphere and silver on the second hemisphere. Using apair of tweezers, a Janus particle was rolled into its non-equilibrium orientation, with the denser Ag painted - coated hemisphere pointing up, e.g., as shown in Fig. 16A, where when the tweezers were released the sphere has rolled to the equilibrium configuration, with the Ag side down, e.g., as shown in Fig. 16B.Example 2: Effect of gravity on Janus particles after shaking

[0305] The Janus particles described in Example 1 were confined within plastic grids, and the grids were mechanically agitated. As shown in Figs. 17A-18D, after agitation the Janus particles reoriented to reach gravitational equilibrium, with the denser Ag hemisphere facing downward.Example 3: Moving particles using sound

[0306] Three different prototypes of millimeter-sized particles [red cellulose acetate spheres (COSPHERIC), clear polyethylene spheres with a paramagnetic black coating (COSPHERIC), and the clear polystyrene spheres painted with silver paint as described in Example 1] were placed in a plastic Petri dish. Using a portable speaker placed roughly 1 inch above the particles and Petri dish, a tone of 220 Hz was generated for a period of 3 s. Each type of particle moved to a different position.Example 4: Synthesis of GROVE particles

[0307] Hemispherically-coated microspheres with black paramagnetic coating on a white polyethylene core, approximately 250-300 pm in diameter, (COSPHERIC; part # HCMS-WPMS-BLK 250-300 pm) were suspend in water and reacted with 2-mercaptoethylamine, which binds as a monolayer only to the paramagnetic hemisphere. The particles were then centrifuged at low speed and re-suspended in water. A dilute solution of 12-nm diameter gold (Au) nanoparticles was slowly added, forming a sub-monolayer of Au nanoparticles on the paramagnetic hemisphere. Then, a stepwise assembly method is performed, for example as described in Musick et al., “Metal Films Prepared by Stepwise Assembly. 2. Construction and Characterization of Colloidal Au and Ag Multilayers,” Chem. Mater. Vol. 12, 2000: pp. 2869-81, which is incorporated by reference in its entirety, where the monolayer of Au nanoparticles was converted to a thin, continuous Au film. This yielded a core particle (e.g., as described in Fig. 1), where the denser first material was a hemisphere comprising a optically active agent of a reflective Au surface atop a paramagnetic layer atop white polyethylene, and the less dense material is the optically active white polyethylene.

[0308] The resulting particle was coated with a thin silica shell using a method, for example, as described in Norvilaite et al., “Silica-Coated Micrometer-Sized Latex Particles,” Langmuir, Vol. 39, No. 14, 2023: pp. 5169-78, which is herein incorporated by reference in its entirety. The following reagents wereused: low molecular weight chitosan and tetraethyl orthosilicate (TEOS; 98% purity) (Sigma-Aldrich (UK)), concentrated ammonium hydroxide solution (28%) (Alfa Aesar (UK)), absolute ethanol (^99.8%, HPLC grade) and methanol (>99.8%, HPLC grade) (Fisher (UK)), glacial acetic acid and tetrahydrofuran (THF) (HPLC grade) (VWR (UK)), and deionized water.

[0309] Adsorption of Chitosan onto Particles: Chitosan (2.0 g) was dissolved in 0.1 M acetic acid (100 mL) to produce a 20 g dnr3aqueous stock solution, which was magnetically stirred overnight to ensure complete dissolution. The particles (5.0 g) were dispersed in deionized water (45.0 g) with the aid of magnetic stirring for 5 min. Then one droplet of chitosan stock solution (104 pL, 2.075 mg chitosan) was added to this 10% w / w solution. The suspension was mixed overnight using a roller mixer at 20°C and the chitosan-coated particles were isolated by freeze-drying overnight. A modified Stober method (e.g., described in Norvilaite) was used to deposit a 150-nm silica shell.

[0310] The resulting thin silica coating was grown to a shell thickness of 2 pm, by performing methods as described, for example, in Bogush et al., ’’PREPARATION OF MONODISPERSE SILICA PARTICLES: CONTROL OF SIZE AND MASS FRACTION.” Journal of Non-Crystalline Solids, Vol. 104, 1988: pp. 95-106, wherein is herein incorporated by reference in its entirety. Formation of a yolk-shell geometry of the GROVE particle (e.g., as shown in Fig. 1) followed the procedures described, for example, in Watanabe et al., “Polyethylenimine-assisted synthesis of hollow silica spheres without shape deformation,” Mater. Chem. Phys. Vol. 262, No. 124267, 2021: pp. 1-6, which is herein incorporated by reference in its entirety. Specifically, the 2 pm thick coated silica particles were dispersed in an ethanol solution of polyethyleneimine (PEI) to a volume fraction of roughly 0.001 % (w / v). The particle solutions were sonicated for 15 minutes, followed by stirring for 30 min at ambient temperature (approx. 22°C). The suspensions of PEI-modified particles were centrifuged in an ethanol water mixture twice at 8000 rpm for 15 minutes each time, and were then re-suspended in water. The aqueous suspensions of the PEI-modified silica particles were stirred for 18 hr at 50°C for dissolution of the particle interiors. The volume fractions of the PEI-modified particles in the silica dissolution process were the same as those in the surface modification process. After centrifugation at 8000 rpm for 15 min, the obtained GROVE particles (e.g., similar to that described in Fig. 1) were dispersed in water.Example 5: Synthesis of GROVE particle with core particle produced by microfluidics

[0311] Core Janus particles were prepared using a synthesis method according to, for example, Nisisako et al., "Synthesis of Monodisperse Bicolored Janus Particles with Electrical Anisotropy Using aMicrofluidic Co-Flow System,” Adv. Mater., 2006, Vol. 18, 2006: pp. 1152-56, which is herein incorporated by reference in its entirety. The Janus particles were made by microfluidic mixing of streams of carbon black (e.g., black in color) in isobornyl acetate (IBA) and titania in IBA (e.g., white in color). The image of the resulting particles shown in Fig. 3a of Nisisako et al., 2006 is reproduced in Fig. 21 A, with an illustrative, nonlimiting diagrammatic representation of the particles in Fig. 21 B. The particles were approximately 120 pm in diameter. The carbon black had a density of approximately 1.9-2.0 g / cm3, while the titania had a density of approximately 1.7 g / cm3, so at equal volume loading and at equilibrium, the black carbon hemispherical portion was facing downward. However, in Nisisako et al., 2006 the loading of 24-nm diameter carbon black was at 3 wt%, and the loading of 250 nm diameter titania was at 10 wt %, so in fact the denser first material was the titania / polymerized IBA, and the less dense material was the carbon black / polymerized IBA.

[0312] To convert the above core particles into GROVE particles, a resorcinol-formaldehyde polymer dissolution-regrowth approach was used, for example, as described in Zhou et al., “Formation of Resorcinol- Formaldehvde Hollow Nanoshells through a Dissolution-Reqrowth Process,” Nanoscale, 2020, Vol. 12, 2020: pp. 15460-65, which is herein incorporated by reference in its entirety. Resorcinol and formaldehyde were polymerized using a modified Stober method to form a core-shell particle, and then the inner part of the shell was dissolved using a solvent (e.g., ethanol or tetrahydrofuran). Specifically, 1 ml_ of the microfluidically- generated carbon black / titania Janus core particles suspended in water were sonicated, and then mixed with 50 mg resorcinol and 70 pL of a formaldehyde solution, which was added to an aqueous ammonia solution (NH4OH), 160 pL, 2.8 wt%). The resulting solution was sonicated for 1 hr at room temperature (approx. 22°C). The resulting mixture was centrifuged and redispersed in water several times. To form the yolk-shell particles, an etching solution comprising 1 mL of ethanol was added and dispersed ultrasonically, with subsequent stirring for 10 minutes. The resulting GROVE particles were collected and purified by repeated centrifugation / water resuspension cycles.

[0313] Other types of particles are made by microfluidics, including but not limited to, using variations of the conditions described in Nisisako et al., 2006. In embodiments, the microfluidic channel are Y-shaped or other shapes that enable co-flow. Microfluidics channels could be used to make emulsion droplets or be used in microfluidic flow-focusing devices. In embodiments, steric stabilizers are added to flow systems and / or Y-junctions, including but not limited to poly(vinyl alcohol), polyvinylpyrrolidone, polyethylene glycol, Pluronic, and poly(acrylic acid).

[0314] In embodiments, the molecular weight of the steric stabilizers are roughly 3000 g / mol, or 5,000 g / mol, or 10,000 g / mol, or higher than 10,000 g / mol. Such stabilizers are added at 0.1 wt %, or 0.5 wt %, or 1 .0 wt %, or 2 wt %.

[0315] In embodiments, the viscosities of the two fluid components are closely matched, or are dissimilar. The room-temperature viscosities of the liquids used to form Janus particles by microfluidics is between 1 -5 cP, or between 5-10 cP, or between 10-15 cP, or between 15-20 cP, or 20-25 cP, or 25-30 cP, or 30-35 cP, or 35-40 cP, or 50-60 cP, or 60-70 cP, or 70-80 cP, or 80-100 cP, or 100-120 cP, or 120-140 cP, or 140-160 cP, or 160-200 cP, or 200-250 cP, or 250-300 cP, or 300-400 cP, or 400-500 cP, or 500-1000 cP, or 1000-1500 cP, or 1500-2000 cP, or 2000-3000 cP, or above 3000 cP.

[0316] In embodiments, the Capillary number (Ca) is 0.001 , or between 0.001 and 0.01 , or between 0.01 and 0.1 , or greater than 0.1.Example 6: GROVE particles made using Janus particles fabricated by evaporation

[0317] The optically variable core particles of GROVE particles were manufactured by evaporation following a procedure, for example, as described in Tkachenko et al., “Evanescent field trapping and propulsion of Janus particles along optical nanofibers,” Nature Communications, Vol. 14, No. 1691 , 2023: pp. 1-11, which is herein incorporated by reference in its entirety. Silica-gold (Au) Janus particles were prepared by first using a loosely packed monolayer of silica microspheres (3.13 ± 0.2 pm, Bangs Laboratories, Inc.) formed on a glass substrate by drop-casting them in an ethanol suspension and drying under ambient conditions (approx. 22°C, 1 atm pressure). Next, the substrate was loaded into an electron beam evaporator (MEB550S2-HV by PLASSYS-BESTEK) and sequentially coated with a 5-nm-thick adhesion layer of titanium and a 100-nm-thick layer of gold. Then, the Janus particles were detached from the substrate by sonication for 10 minutes in ultrapure water. With reference, for example, to the diagram of the GROVE particle in Fig. 1 , the Au-coated silica hemisphere was the denser optically active first material 104, and the uncoated silica hemisphere was the less dense optically active second material 106.

[0318] GROVE particles were fabricated using the silica-Au core particle above with a modification of the procedure described in Watanabe et al., 2017, which describes the generation of a freely movable yolk silica particle within a silica shell, starting with a silica core; herein the method was adapted at the first step to accommodate a silica particle with a hemispherical Au shell.

[0319] Synthetic Procedure. Yolk / Shell Particles Incorporating a Silica / Au hemispherical Core

[0320] Materials: Tetraethyl orthosilicate (TEOS, 95%), titanium tetraisopropoxide (TTIP, 95%), acetonitrile (99.5%), ammonia aqueous solution (25 wt %), methylamine aqueous solution (40 wt%), ethanol (99.5%), styrene (St, 99%), p-styrenesulfonic acid sodium salt (NaSS, 80%), and potassium persulfate (KPS, 95.0%) (Wako Pure Chemical Industries, Osaka, Japan). 3-Methacryloxypropyltrimethoxysilane (MPTMS, 95.0%) (Shinetu Chemical, Tokyo, Japan). (3-aminopropyl)trimethoxysilane (APTMS) (Sigma Aldrich). The inhibitor for the St monomer was removed by using an inhibitor removal column. Polyvinylpyrrolidone (PVP, MW = 360 000 g / mol) (Tokyo Chemical Industry). Polyfallylamine hydrochloride) (PAH, MW = 15 000 g / mol, Aldrich.

[0321] Silica / Au particles suspended in deionized water at 35 °C (0.15 vol%) was added a mixture of 1 mM MPTMS and 1 mM APTMS. [Watanabe et al., used 2 mM MPTMS to coat the silica surface, in this case, only half the surface is silica, so the concentration was decreased by 2x, and APTMS was added to bind to the Au surface via the amine group.] St (50 mM) and an aqueous solution of NaSS were added to the suspension of the surface-modified cores. After stirring for 30 min at 65°C, an aqueous solution of KPS was added to the suspension as an initiator. Formation of a PSt shell was conducted at [KPS] of 2 mM, [NaSS] of 0.25 mM, and a silica concentration of 0.15 vol%. To further increase the thickness of the PSt shell, another polymerization of St was conducted at a concentration of 100 mM or 200 mM with KPS initiator (2 mM). The second formation of PSt shell was performed at a core / shell particle concentration of 0.05 vol%. Next, the doubly poly-St-coated silica / Au particles were further coated with silica. A suspension of the PSt-coated particles was added to a solution containing PAH and NaCI. The concentrations of the doubly PSt-coated particles, PAH, and NaCI were 0.15 vol %, 0.71 kg / m3, and 36 mol / m3in the mixture, respectively. After two centrifugation steps to remove non-adsorbed PAH and NaCI, the particles were redispersed into 40 mL of an ethanol solution containing 0.20 g of polyvinylpyrrolidone (PVP). Two more centrifugation steps were conducted to remove excess PVP and the resultant particles were redispersed into 9.59 mL of ethanol. To the ethanol solution, 10.6 mL of ammonia solution, as well as the silica precursors TEOS (1 mL) and APTMS (37 pL) were added. The mixed silica precursors were used to form a low-density silica shell suitable for the next step, a slight etching of silica. Poly-St particles coated with silica were dried at 50°C, followed by heat treatment for 4 hr in an oven at 500°C. Particles obtained by the heat treatment were immersed in 30 mL of ammonia solution (15-20 mM, approximately pH 11) to slightly etch the silica component of the particles. This detaches the cores from the shells, resulting in the GROVE particles.Example 7: Janus particles fabricated bv evaporation

[0322] 6-micron diameter polymethylmethacrylate particles were obtained from Lamberti. 4” diameter n-type silicon wafers with a thermal oxide coating were obtained from University Wafer. The wafers were coated with a fluorosilane polymer by Integrated Surface Technologies, and then used as received. A monolayer of particles was formed on the wafer using the protocols and materials described in Ignaas S. M. Jimidar, et al., Langmuir2020 36 (24), 6793-6800. Using e-beam evaporation, a 10-nm titanium (Ti) adhesion layer, followed by a 90-nm thick gold (Au) coating was applied to the substrate by Silson, Ltd. The resulting Janus particles were removed by lightly scraping the surface using a plastic spatula.Example 8: Alternative Janus particle

[0323] 2.5-micron diameter SiC>2 particles with methyacrylate surface functional groups was prepared as described herein. The particles were dried at 80°C for one hour in air. 4” diameter n-type silicon wafers with a thermal oxide coating were obtained from University Wafer. The wafers were coated with a fluorosilane polymer by Integrated Surface Technologies, and then used as received. A monolayer of particles was formed on the wafer using the protocols and materials described in Ignaas S. M. Jimidar, et al., Langmuir 2020 36 (24), 6793-6800. Using e-beam evaporation, a 25-nm titanium (Ti) adhesion layer, followed by a 75- nm thick iron (Fe) coating was applied to the substrate by Nova Electronic Materials Inc. The resulting Janus particles were removed by lightly scraping the surface using a plastic spatula.Example 9: Raspberry-Shaped Core Particles

[0324] A 0.1% (w / v) polystyrene sphere solution was prepared in deionized water and adjusted to pH 10.7-10.9 by adding ammonium hydroxide (28-30% (w / v)). Next, 0.5% (v / v) of methacryloxypropyltrimethoxysilane (MPTMS) was added to the polystyrene sphere solution which was agitated for 1 hour. 5 mg of azobisisobutyronitrile (Al BN) was added and the mixture was tumbled gently. The reaction tube was placed in an oven at 80°C overnight for polymerization. Finally, the particles were washed by centrifugation (800 rpm, 3 minutes) and redispersed in deionized water, followed by two washes with 50% ethanolic water, and a final wash with neat ethanol. As shown in the representative SEM image of Fig. 37, a uniform sample of “raspberry shaped” core particles comprising a polystyrene core with silica lobes on the polystyrene surface were produced. The core particles were uniform in shape and under 5 pm in dimension. The images demonstrated, inter alia, that core particle features (e.g., shape, geometry, roughness features, dimensions, thickness, etc.) are controllable using varying concentrations of components, polymerization incubation periods, and different rounds of polymerization.Example 10: Polystyrene Growth on Silica

[0325] A protocol was adapted from Langmuir 2015, 31 , 19, p. 5306-5310, to prepare 3 pm methacrylate-functionalized silica spheres, which were hydrolyzed and condensed in 3% (v / v) methacryloxypropyltrimethoxysilane (MPTMS) in aqueous ammonia (at pH 10.7-10.9) with continuous stirring for 2 hours. The methacryl groups of MPTMS were polymerized by adding 10 mg of azobisisobutyronitrile (AIBN) as an initiator and the mixture was heated at 80°C overnight. A polystyrene coating was formed by performing soap-free polymerization using styrene (St), sodium polystyrenesulfonate (NaSS), and sodium persulfate (APS) as the initiator. Polymerization was performed in a nitrogen atmosphere at 65°C for 16 hours in a 20 mL reaction volume, using 50 mg of core particles, 4 mg of NaSS, 417 mg of St, and 40 mg of APS. The thickness of the polystyrene layer was increased (e.g., controlled), with repeated polymerization using the coated particles as seeds. As shown in the representative SEM images of Figs. 38A-38B, a uniform sample of 3 pm diameter methacrylate-functionalized silica spheres (core particles) were formed before (Fig. 39A) and after coating with polystyrene (Fig. 38B). These images demonstrated, inter alia, that core particle features (e.g., shape, geometry, roughness features, dimensions, thickness, etc.) are controllable using varying concentrations of components, polymerization incubation periods, and different rounds of polymerization. An alternative type of silica coating was prepared by using vinyltrimethoxysilane (VTMS) in place of MPTMS as described above, while otherwise following the same protocol. As shown in Figs. 40A- 40D, this process was successfully carried out with polystyrene or polymethylmethacylate particles, leading silica coatings with vinyl group surface functionality.Example 11: Silica growth on polymer

[0326] A 0.25% (w / v) polystyrene sphere solution in deionized water was prepared and the pH was adjusted to 10.7-10.9 by adding ammonium hydroxide (28-30% (w / v)). 0.5% (v / v) MPTMS was added and the mixture was agitated for 1 hour. 5 mg of azobisisobutyronitrile (AIBN) then added and the mixture was gently tumbled and then the reaction was placed in an oven at 80°C overnight for polymerization. To alter (e.g., fill) the silica lobe interstices, the MPTMS growth was repeated using the silica lobe-coated polystyrene spheres as seeds. As shown in the representative SEM images of Figs. 39A-39F, polystyrene core particles of approximately 3 pm in dimension were formed (Fig. 39A), and polystyrene core particles of approximately 5 pm were formed (Fig. 39D). Figs. 39B and 39E show the initial silica lobe growth, and Figs. 39C and 39F show the silica growth filling the lobe interstices. These images demonstrated, inter alia, that core particle features (e.g., shape, geometry, roughness features, dimensions, thickness, etc.) are controllable using varying concentrations of components, polymerization incubation periods, and different rounds of polymerization.Example 12: SiO2 removal by HF

[0327] Polystyrene-silica-polystyrene core-shell-shell particles were prepared by growing a silica layer on polystyrene spheres using the method as substantially described in Example 10. Next, a crosslinked polystyrene shell was formed on the silica-coated polystyrene via soap-free polymerization with styrene (St), sodium polystyrenesulfonate (NaSS), divinylbenzene (DVB) as the crosslinker, and sodium persulfate (APS) as the initiator. Polymerization was performed in a nitrogen atmosphere at 65°C for 16 hours in a 10 mL reaction volume, using 25 mg of core particles, 2 mg of NaSS, 200 mg of St, 10 mg of DVB, and 20 mg of APS. Finally, the silica layer was dissolved by immersing the core-shell-shell particles in 16% (w / v) hydrofluoric acid (HF) overnight, followed by washing the particles 3 times with ethanol. As shown in the SEM image of Figs. 41A, polystyrene-silica-polystyrene core-shell-shell spheres (encapsulated core particles) were successfully formed. As shown in the SEM image of Fig. 41 B, a void space between the encapsulated core particles and the shell is observed after the silica was removed. These images demonstrated, inter alia, that core particle can be encapsulated within a shell, having a void space between the core particle and the shell, such that the core particle would be free to move therein.Example 13: Polymer Removal by Solvent

[0328] Polystyrene-silica-polystyrene core-shell-shell particles were prepared by growing a silica layer on polystyrene spheres using the method as substantially described in Example 10. Next, a crosslinked polystyrene shell was formed on the silica-coated polystyrene via soap-free polymerization with styrene (St), sodium polystyrenesulfonate (NaSS), divinylbenzene (DVB) as the crosslinker, and sodium persulfate (APS) as the initiator. Polymerization was performed in a nitrogen atmosphere at 65°C for 16 hours in a 10 mL reaction volume, using 25 mg of core particles, 2 mg of NaSS, 200 mg of St, 10 mg of DVB, and 20 mg of APS. The polystyrene layer was dissolved by immersing the core-shell-shell particles in 16% (w / v) hydrofluoric acid (HF) overnight, followed by washing three times with ethanol. As shown in the SEM images of Figs. 42A-42D, sub-5 pm diameter iron-capped silica particles coated with polystyrene and then with silica were formed Fig. 42B shows the corresponding particles after removal of the polystyrene coating, with the box highlighting the presence of a void space between the shell and core particle. Fig. 42C shows a closeup of the region highlighted by the white box in Fig. 42A. Fig. 42D shows a close-up of the region highlighted by the white box in Fig. 42B. These images demonstrated, inter alia, that core particle can be encapsulated within a shell, having a void space between the core particle and the shell, such that the core particle wouldbe free to move therein, and that either the shell and / or core material can be composed of metal, polymer, or silica.Example 14: Swellable polymer on polymethylmethacrylate (PMMA)

[0329] This example demonstrates that encapsulated particles are formable using swelling or deswelling on a PMMA particle, which is achieved by depositing a swellable polymer network around the seed particles. PMMA particles were synthesized through dispersion polymerization (are also commercially- available). A pH-responsive swellable shell was grown around 6 pm PMMA seed particles using 25 mg seeds dispersed in 40 ml_ acetonitrile. The dispersion was transferred to a flask equipped with a condenser. The dispersion was gently stirred, heated to 70°C, and purged with nitrogen for 30 min. A pH-responsive monomer mixture with 0.56 M methacrylic acid and 0.014 M ethylene glycol di methacryl ate was prepared and added to the flask. The mixture was equilibrated for 10 minutes. The polymerization was initiated by adding 1 mM azobisisobutyronitrile (AIBN) and was incubated for 4.5 hours. The reaction was quenched in an ice bath. The resulting product was purified using centrifugation (800 x g, 3 minutes) and by washing with ethanol 3 times, washing with water twice, and then resuspended in water. The final dispersion exhibited strong pH-responsive swellability. Swelling was triggered by increasing the solution pH to or above the pka of the swellable polymer using a phosphate buffer or NaOH solution. As shown in the optical microscope images of Figs. 43A-43C, the polymethylmethacrylate particle diameter increased by approximately 2-fold, as a function of increased pH, e.g., where Fig. 43A shows particles before swelling, Fig 43B shows particles after coating with a swellable methacrylic acid-based polymer, and Fig. 43C shows particles after pH-induced swelling, clearly demonstrating a swelled size. These images demonstrated, inter alia, that swellable materials (e.g., in response to pH, metal ion concentration, temperature, etc.) are usable to generate GROVE particles to, for example, control formation of the void space and the shell layer.Example 15: Swellable polymer on silica

[0330] This example utilized substantially the same protocol as described in Example 14 to grow a swellable shell around silica particles. The silica particles were produced from silane hydrolytic condensation (are also commercially-available). The swelling was triggered by increasing the solution pH to or above the pka of swellable polymer using phosphate buffer or NaOH solution. As shown in the optical microscope images of Figs. 44A-44C, the methacrylate-based silica particle diameter increased by approximately 2-fold, as a function of increased pH, e.g., where Fig. 44A shows methacrylate-based silica particles, Fig. 44B shows particles after coating with a swellable methacrylic acid-based polymer, and Fig. 44C shows particlesafter pH-induced swelling, clearly demonstrating a swelled size. These images demonstrated, inter alia, that swellable materials (e.g., in response to pH, metal ion concentration, temperature, etc.) are usable to generate GROVE particles to, for example, control formation of the void space and the shell layer.DEFINITIONS

[0331] The following definitions are used in connection with the disclosure disclosed herein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of skill in the art to which this disclosure belongs.

[0332] As used herein, “a,” “an,” or “the” can mean one or more than one.

[0333] Further, the term “about” when used in connection with a referenced numeric indication means the referenced numeric indication plus or minus up to and including 10% of that referenced numeric indication. For example, the language “about 50” covers the range of 45 to 55.

[0334] In embodiments, the terms “at least one” and “one or more” are used interchangeably.

[0335] As referred to herein, all compositional percentages are by weight of the total composition, unless otherwise specified. As used herein, the word “include,” and its variants, is intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that may also be useful in the compositions and methods of this technology. Similarly, the terms “can” and “may” and their variants are intended to be non-limiting, such that recitation that an embodiment can or may comprise certain elements or features does not exclude other embodiments of the present technology that do not contain those elements or features.

[0336] Although the open-ended term “comprising,” as a synonym of terms such as including, containing, or having, is used herein to describe and claim the disclosure, the present disclosure, or embodiments thereof, may alternatively be described using alternative terms such as “consisting of” or “consisting essentially of.”

[0337] In embodiments, as used herein, the words “preferred” and “preferably” refer to embodiments of the technology that afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the technology.

[0338] In embodiments, the disclosure is directed to the following embodiments:

[0339] Embodiment 1. A gravity responsive optically variable encapsulated (GROVE) particle comprising (i) one or more core particles comprising at least two materials of distinct density, (ii) at least two optically active agents, and (iii) an outer shell at least partially encapsulating the one or more core particles and configured to confine the one or more core particles, wherein at least a portion of the outer shell is optically transparent to at least a portion of electromagnetic radiation between frequencies of about 10 nm to about 10 cm, and wherein the one or more core particles is configured to move as a function of exposure to a force and the GROVE particle exhibits a change in an optical property as a function of the movement.

[0340] Embodiment 2. The GROVE particle of embodiment 1 , wherein the change in optical property is a change in color in the electromagnetic (EM) spectrum between about 300 nm and about 1200 nm, optionally wherein the change in color is in the human visible EM spectrum from about 380 nm to about 750 nm.

[0341] Embodiment 3. The GROVE particle of embodiment 1 or 2, wherein the outer shell comprises a dimension of about or at least 10 nm, about or at least 20 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm, about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, or about or at least about 1000 pm.

[0342] Embodiment 4. The GROVE particle of any one of embodiments 1-3, wherein the one or more core particle comprises a dimension of about or at least 5 nm, about or at least about 15 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm (1 pm), about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 250 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, or about or at least about 1000 pm.

[0343] Embodiment 5. The GROVE particle of any one of the preceding embodiments, wherein a ratio of densities between the at least two materials is about or at least about 1 :1.01 , about or at least about 1 : 1 .05, about or at least about 1 :1.1 , about or at least about 1 :1.2, about or at least about 1 :1.3, about or at least about 1 :1.4, about or at least about 1:1.5, about or at least about 1 :2, about or at least about 1 :3, about or at least about 1 :4, about or at least about 1:5, about or at least about 1 :6, about or at least about 1 :7, about or at least about 1 :8, about or at least about 1 :9, about or at least about 1 :10.

[0344] Embodiment 6. The GROVE particle of any one of the preceding embodiments, wherein the optically active agents are disposed on the one or more core particles, and / or wherein the one or more core particles comprises materials which are optically active agents.

[0345] Embodiment 7. The GROVE particle of any one of the preceding embodiments, wherein the one or more core particles comprises materials which are (or act as) optically active agents.

[0346] Embodiment 8. The GROVE particle of any one of the preceding embodiments, wherein the at least two materials comprise one or more of metals, metal oxides, metal nitrides, inorganic materials, silica, organic materials, organic polymers, inorganic polymers, biological polymers, synthetic polymers, and combinations thereof.

[0347] Embodiment 9. The GROVE particle of any one of the preceding embodiments, wherein the one or more core particles comprises two optically active agents, three optically active agents, four optically active agents, or five or more optically active agents.

[0348] Embodiment 10. The GROVE particle of any one of the preceding embodiments, wherein the one or more optically active agents exhibits a color in the visible electromagnetic spectrum and / or comprising an extinction, reflection, or scattering at a wavelength from about or at least about 300 nm to about or at least about 1200 nm, optionally where the GROVE particle exhibits a discernable optical effect within the visible spectrum.

[0349] Embodiment 11. The GROVE particle of embodiment 10, wherein the color is one or more of white, black, red, orange, yellow, green, blue, indigo, and violet, or a color shade or hue therebetween.

[0350] Embodiment 12. The GROVE particle of any one of the preceding embodiments, wherein the one or more optically active agents comprises a dye.

[0351] Embodiment 13. The GROVE particle of embodiment 12, wherein the dye comprises one or more of Rhodamine B, Congo Red, Crystal Violet, Methylene Blue, Acridine Orange, Nile Red, Malachite Green, Eosin Y, Cresol Red, Fluorescein, and Indigo.

[0352] Embodiment 14. The GROVE particle of any one of the preceding embodiments, wherein the one or more optically active agents comprises a pigment.

[0353] Embodiment 15. The GROVE particle of embodiment 14, wherein the pigment comprises a water-soluble pigment.

[0354] Embodiment 16. The GROVE particle of embodiment 14, wherein the water-soluble pigment comprises one or more of anthocyanin, anthraquinone, carotenoid, violacein, melanin, pyocyanin, prodiginines, asperversin, benzoquinone, anthraquinone, and derivatives thereof.

[0355] Embodiment 17. The GROVE particle of embodiment 14, wherein the pigment comprises one or more of Titanium White (PW6), Zinc White (PW4), Carbon Black (PBk7), Mars Black (PBk11), Iron Oxide Red (PR101 ), Cadmium Red (PR108), Alizarin Crimson (PR83), Cadmium Orange (PO20), Cadmium Yellow (PY35), Lemon Yellow (PY3), Chromium Green Oxide (PG17), Phthalo Green (PG7), Ultramarine Blue (PB29), Cobalt Blue (PB28), Cerulean Blue (PB35), Prussian Blue (PB27), Burnt Sienna (PBr7), Raw Umber (PBr7), Raw Sienna (PBr7), and Yellow Ochre (PY43).

[0356] Embodiment 18. The GROVE particle of embodiment 14, wherein the pigment is an organic pigment.

[0357] Embodiment 19. The GROVE particle of embodiment 14, wherein the pigment is an inorganic pigmen.

[0358] Embodiment 20. The GROVE particle of embodiment 18 or 19, wherein the organic pigment or inorganic pigment is a white pigment.

[0359] Embodiment 21. The GROVE particle of embodiment 20, wherein the white pigment is one or more of lead white (2PbCO3-Pb(OH)2), kaolin, silica (SiO2), Titanium dioxide (TiO2 / rutile and anatase), zinc oxide (ZnO), zinc sulfide (ZnS), and / or lithopone (ZnS + BaSO4).

[0360] Embodiment 22. The GROVE particle of embodiment 18 or 19, wherein the organic pigment or inorganic pigment is a black pigment.

[0361] Embodiment 23. The GROVE particle of embodiment 22, wherein the black pigment is one or more of coal (charcoal), groutite (o-MnOOH), manganite (y-MnOOH), hausmannite (MnsOi), Carbon black, graphene, graphite, iron oxide black (Fe3O4), and / or spinel black (CuCr2O4).

[0362] Embodiment 24. The GROVE particle of embodiment 18 or 19, wherein the organic pigment or inorganic pigment is a colored pigment.

[0363] Embodiment 25. The GROVE particle of embodiment 24, wherein the colored pigment comprises a yellow pigment.

[0364] Embodiment 26. The GROVE particle of embodiment 25, wherein the yellow pigment comprises one or more of yellow ochre (o-FeOOH), auric pigment (AS2S3), lead ochre (PbO), lead tin yellow (Pb2SnO4, PbSn2SiO?), Naples yellow (Pb(SbO3)2), zinc yellow (Zn2CrO4), Indian yellow (C19H16O10), Iron oxide yellow (o-FeOOH), chromium titanium yellow ((Ti,Cr,Sb)O2), nickel titanium yellow ((Ti,Ni,Sb)O2), lead yellow (PbCrO4), cadmium yellow (CdS), bismuth yellow (BiVO4).

[0365] Embodiment 27. The GROVE particle of embodiment 24, wherein the colored pigment comprises a red pigment.

[0366] Embodiment 28. The GROVE particle of embodiment 27, wherein the red pigment comprises one or more of red ocher (o-Fe2O3), Terra di Siena (a-Fe2O3), vermilion (HgS), lead red (Pb3O4), alizarin madder varnish, alizarin red (C14H8O4), Iron oxide red (a-Fe2O3), molybdate red (Pb(Cr,S,Mo)O4), cadmium red (Cd(S,Se)).

[0367] Embodiment 29. The GROVE particle of embodiment 24, wherein the colored pigment comprises a green pigment.

[0368] Embodiment 30. The GROVE particle of embodiment 29, wherein the green pigment comprises one or more of green earth (Fe silicates), Schweinfurt green (C4H6AS6CU4O16), chromium oxide green (Cr2O3), chromium oxide hydrate green (CrOOH), cobalt green (Co2TiO4).

[0369] Embodiment 31. The GROVE particle of embodiment 24, wherein the colored pigment comprises a blue pigment.

[0370] Embodiment 32. The GROVE particle of embodiment 31 , wherein the blue pigment comprises one or more of lazurite (lapis lazuli), Egyptian blue (CaCuSi40io), azurite (2CuCO3 Cu(OH)2), malachite (CUCO3'CU(OH)2), cobalt blue (COAI2O4), cobalt blue (COAI2O4), ultramarine blue: (NaeAl6Si6O24(NaSn)), iron bluea (K[FelllFell(CN)6] xH2O).

[0371] Embodiment 33. The GROVE particle of embodiment 24, wherein the colored pigment comprises a brown pigment.

[0372] Embodiment 34. The GROVE particle of embodiment 33, wherein the brown pigment comprises one or more of burnt umber (Fe2O3 xMnO2), brown ocher (o-Fe2O3 + Mn oxides), limonite (mixture of different Fe oxides).

[0373] Embodiment 35. The GROVE particle of any one of the preceding embodiments, wherein the pigment is one or more of an oxide or oxide hydroxide pigment (TiO2, ZnO, a-Fe2O3, a-FeOOH, y-Fe2O3, Fe3O4, Cr2O3, CrOOH, PbO, PB3O4, MnsO4, -MnOOH, Sb20s), a complex oxide pigment (C0AI204, CuCr2O4, Co2TiO4, (Ti,Ni,Sb)O2, (Ti,Cr,Sb)O2), a carbonate hydroxide pigment (2PbCO3'Pb(OH)2, 2CuCO3-Cu(OH)2, CUCO3-CU(OH)2), a sulfide / selenide pigment (ZnS, CdS, Cd(S,Se), CdSe, y-Ce2S3, HgS, AS2S3), a chromate / molybdate pigment (PbCrO4, Pb(Cr,S)O4, Pb(Cr,S,Mo)O4, ZnCrO4, BaCrO4, SrCrO4), a vanadate pigment (BiVO4, 4BiVO4-3Bi2MoOe), a stannate pigment (Pb2SnO4, PbSn2SiO?, Co2SnO4, CoSnOs), a phosphate pigment (Co3(PO4)2), an antimonate pigment (Pb(SbO3)2), an arsenate pigment (Cu(AsO3)2), an ultramarine pigment (Na6Al6SisO24(NaSn)), a hexacyanidoferrate / hexacyanoferrate pigment (K[FelllFe"(CN)6]-xH2O (x = 14-16)), an oxonitride pigment (CaTaO2N, LaTaON2), an elemental-based pigment (C, Al, Cu, Cu / Zn, Au), a doped metal-based pigment, a spinel-based pigment, and / or a rutile-based metal pigment.

[0374] Embodiment 36. The GROVE particle of embodiment 19, wherein the inorganic pigment is one or more of a transparent effect pigment, goniochromatic pigment, pearlescent pigment, metallic pigment,interference pigment, metallic effect pigment, fluorescent pigment, luminescent pigment, phosphorescent pigment, magnetic pigment, and anticorrosive pigment (e.g., “special optical materials”).

[0375] Embodiment 37. The GROVE particle of embodiment 36, wherein the metallic pigment comprises one or more of aluminum, bronze, and copper metallic pigment.

[0376] Embodiment 38. The GROVE particle of embodiment 36, wherein the pearlescent pigment comprises one or more of mica, titanium dioxide, and bismuth oxychloride.

[0377] Embodiment 39. The GROVE particle of embodiment 36, wherein the fluorescent pigment comprises one or more fluorescent dye and pigment comprising a fluorescent mineral.

[0378] Embodiment 40. The GROVE particle of embodiment 36, wherein the phosphorescent pigment comprises zinc sulfide and / or strontium aluminate.

[0379] Embodiment 41. The GROVE particle of embodiment 36, wherein the interference pigment comprises titanium dioxide-coated mica and / or aluminum oxide-coated mica.

[0380] Embodiment 42. The GROVE particle of any one of the preceding embodiments, wherein the one or more optically active agents comprises an anisotropic particle.

[0381] Embodiment 43. The GROVE particle of embodiment 42, wherein the anisotropic particle comprises a nanoparticle of the one or more metals, optionally comprising a nanorod of one or more of gold (Au), silver (Au), and aluminum (Al).

[0382] Embodiment 44. The GROVE particle of any one of the preceding embodiments, wherein the at least two optically active agents comprise a plasmonic material.

[0383] Embodiment 45. The GROVE particle of embodiment 44, wherein the plasmonic material comprises a pigment, particle, foil, and / or film.

[0384] Embodiment 46. The GROVE particle of embodiment 44, wherein the plasmonic material comprises a polymer-film loaded with noble metal nanoparticles.

[0385] Embodiment 47. The GROVE particle of embodiment 36, wherein the goniochromatic pigment comprises aluminum coated with magnesium fluoride embedded in chromium.

[0386] Embodiment 48. The GROVE particle of any one of the preceding embodiments, wherein at least one of the at least two materials comprise a magnetic material.

[0387] Embodiment 49. The GROVE particle of embodiment 48, wherein the magnetic material is ferromagnetic, ferrimagnetic, antiferromagnetic, diamagnetic, paramagnetic, superparamagnetic, and / or antiferromagnetic.

[0388] Embodiment 50. The GROVE particle of embodiment 48 or 49, wherein the magnetic material comprises one or more of an inorganic, organic, carbon-based, or biomolecule-based magnetic material.

[0389] Embodiment 51 . The GROVE particle of any one of embodiments 48-50, wherein the magnetic material comprises one or more of iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), manganese (Mn), chromium (Cr), samarium (Sm), alloys or oxides thereof; alloys, intermetallic, and / or oxides of Fe, Co, Ni, Zn, Mn, Sm; oxides are of iron, Fe2O3, FeO, and / or Fe3O4; ferrite material and / or doped materials of Co, Ni, Zn, and / or MmFexOy, and / or magnetitetetracyanoethylene (TCNE) salts, [Fe(C5Me5)2]+[TCNE]«-, Li[TCNE], [MnllTPP][TCNE]« (TPP = tetraphenylporphyrin), [Fell(TCNE)(NCMe)2][FelllCI4], Mnll(TCNE)l(OH2), Mnll(TCNE)[C4(CN)8]1 / 2, Fe(TCNE)[C4(CN)8]1 / 2, Mnll(TCNE)3 / 2(l3)1 / 2, VII[TCNE]x (x « 2), C7H5CIN3Se4, magnetic organic polymers, and polymer-bonded magnets.

[0390] Embodiment 52. The GROVE particle of any one of the preceding embodiments, wherein the at least two materials, the optically active agents, and / or the outer shell is or comprises a polymeric material.

[0391] Embodiment 53. The GROVE particle of any one of the preceding embodiments, wherein the at least two materials, the optically active agents, and / or the outer shell is or comprises silica (SiOz).

[0392] Embodiment 54. The GROVE particle of embodiment 52, wherein the polymeric material comprises one or more of a plastic, acrylic resin, styrene acrylic copolymer, vinyl acetate ethylene copolymer, polyvinyl acetate, polyvinyl butyral, polyvinyl chloride, polyurethane, epoxy resin, alkyd resin, cellulose acetate, silicone resin, a fluoropolymer resin, chlorinated rubber, a copolymer derived from maleic anhydride, ethylene vinyl acetate, polyethylene, polypropylene, polyamides (nylons), polyester resins, polybutadienes, thermally responsive polymers, latex, hydrocarbons, crude oil derivatives and / or petroleum derivatives, poloxamers, styrene-butadiene block copolymers, polymethylmethacrylate, polybutylmethacrylate, poly(tert- butyl acrylate)-poly(3-(triethoxysilyl)propyl methacrylate) (PtBA-PTPM), polystyrene latex polymer, carboxylated latex polymer, aminated latex polymer, colored polystyrene polymer (dye-infused and / or pigment-infused), colored polystyrene-based carboxylated latex polymer (dye-infused and / or pigment- infused), fluorescent polystyrene-based polymers, fluorescent polystyrene-based carboxylated latex polymers, fluorescent aminated polystyrene-based polymer, surfactant-free polystyrene, carboxylated surfactant-free polymer, polymethyl methacrylate (PMMA) latex polymer, and / or divinylbenzene-crosslinkedpolystyrene latex, plasticized polyvinyl chloride, plasticized nylon, plasticized polyethylene terephthalate, polyacrylonitrile, polychlorotrifluoroethylene, poly-4, 4'-isopropylidenediphenylene carbonate, polyethylene vinyl ester, polyvinyl chloride-diethyl fumarate, polyethylene terephthalate, polycarbonate, polymethyl methacrylate (acrylic), polyethylene, polyurethane, polypropylene, thermoplastic elastomers, acrylonitrile butadiene styrene, epoxies and epoxy-based photoresists, hydrogels, cyclic olefin copolymer, cyclic olefin polymer, poly dimethyl siloxane, poly ether ester ketone, polyetherimide, and combinations thereof.

[0393] Embodiment 55. The GROVE particle of any one of the preceding embodiments, wherein the at least two materials, the at least two optically active agents, and / or the outer shell comprise one or more naturally occurring polymer and / or biological polymer.

[0394] Embodiment 56. The GROVE particle of any one of the preceding embodiments, wherein the one or more naturally occurring polymer and / or biological polymer comprises one or more of a nucleic acid (DNA, RNA), amino acid (peptide, protein), polysaccharide, and lipid.

[0395] Embodiment 57. The GROVE particle of any one of the preceding embodiments, wherein the outer shell comprises one or more materials.

[0396] Embodiment 58. The GROVE particle of any one of the preceding embodiments, wherein the outer shell comprises one or more layers.

[0397] Embodiment 59. The GROVE particle of any one of the preceding embodiments, wherein the outer shell comprises at least a portion that is opaque.

[0398] Embodiment 60. The GROVE particle of any one of the preceding embodiments, wherein the outer shell comprises a single, uniform thickness and / or varying thicknesses.

[0399] Embodiment 61 . The GROVE particle of embodiment 60, wherein the outer shell comprises a thickness of about or at least about 1 nm, about or at least about 5 nm, about or at least about 10 nm, about or at least about 15 nm, about or at least about 20 nm, about or at least about 25 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 100 nm, about or at least about 200 nm, about or at least about 300 nm, about or at least about 400 nm, about or at least about 500 nm, about or at least about 600 nm, about or at least about 700 nm, about or at least about 800 nm, about or at least about 900 nm, about or at least about 1 pm, about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 10 pm, about or at least about 15 pm, about or at least about 20 pm, about or at least about 25 pm, about or at leastabout 30 pm, about or at least about 35 pm, about or at least about 50 pm, about or at least about 100 pm, about or at least about 200 pm, about or at least about 300 pm, about or at least about 400 pm, about or at least about 500 pm, about or at least about 600 pm, about or at least about 700 pm, about or at least about 800 pm, about or at least about 900 pm, or about or at least about 1000 pm.

[0400] Embodiment 62. The GROVE particle of any one of the preceding embodiments, wherein the outer shell is configured to filter or select for a wavelength or ranges of wavelengths of radiation.

[0401] Embodiment 63. The GROVE particle of any one of the preceding embodiments, wherein the outer shell is configured to transmit a percentage of electromagnetic radiation of about or at least about 100%, about or at least about 99%, about or at least about 98%, about or at least about 97%, about or at least about 96%, about or at least about 95%, about or at least about 94%, about or at least about 93%, about or at least about 92%, about or at least about 91 %, about or at least about 90%, about or at least about 85%, about or at least about 80%, about or at least about 75%, about or at least about 70%, about or at least about 65%, about or at least about 60%, about or at least about 55%, about or at least about 50%, about or at least about 40%, about or at least about 30%, about or at least about 20%, about or at least about 10%, about or at least about 5%, about or at least about 4%, about or at least about 3%, about or at least about 2%, about or at least about 1%, about or at least about 0.5%, about or at least about 0.4%, about or at least about 0.3%, about or at least about 0.2%, about or at least about 0.1 %, about or at least about 0.05%, about or at least about 0.04%, about or at least about 0.03%, about or at least about 0.02%, about or at least about 0.01 %, about or at least about 0.005%, or about or at least about 0.001%, relative to the intensity or amount of electromagnetic radiation that impinges on the outer shell.

[0402] Embodiment 64. The GROVE particle of any one of the preceding embodiments, wherein the outer shell comprises one or more inorganic materials.

[0403] Embodiment 65. The GROVE particle of embodiment 64, wherein the one or more inorganic materials comprise one or more of alumina, silica, titania, silicon nitride, zirconia, copper oxide, iron oxide, cobalt oxide, silver, gold, aluminum, copper, tin oxide, nickel oxide, lead oxide, glass, quartz, sapphire, inorganic glasses, diamond, diamond-like materials, zinc oxide, and manganese oxide.

[0404] Embodiment 66. The GROVE particle of any one of the preceding embodiments, wherein the one or more core particles comprises a Janus particle (JP).

[0405] Embodiment 67. The GROVE particle of any one of the preceding embodiments, wherein the outer shell fully encapsulates the core particle, resulting in a bounded internal volume.

[0406] Embodiment 68. The GROVE particle of embodiment 67, wherein the bounded internal volume comprises one or more of a gas, liquid, polymer, semisolid, and solid material.

[0407] Embodiment 69. The GROVE particle of embodiment 68, wherein the gas is atmospheric air.

[0408] Embodiment 70. The GROVE particle of embodiment 68, wherein the liquid comprises an aqueous liquid, organic liquid, a mixed aqueous-organic mixture, a polymer, and / or a gel.

[0409] Embodiment 71 . The GROVE particle of embodiment 68, wherein liquid comprises one or more additives, preservatives, anti-oxidants, lubricants, emulsifiers, stabilizers, thickeners, anti-foaming agents, humectants, anti-bacterial agents, anti-caking agents, inorganic salts, pH adjusters, pH buffers, and rheology modifiers.

[0410] Embodiment 72. The GROVE particle of embodiment 70, wherein the lubricant comprises one or more of mineral oil, synthetic oil, grease, a silicone-based lubricant, a graphite-based lubricant, molybdenum disulfide, vegetable oils, and Teflon-based lubricants.

[0411] Embodiment 73. The GROVE particle of embodiment 68-72, wherein the one or more gas, liquid, polymer, semisolid, and solid material occupies about or up to about 100%, about or up to about 99%, about or up to about 97%, about or up to about 96%, about or up to about 95%, about or up to about 94%, about or up to about 93%, about or up to about 92% about or up to about 91 % about or up to about 90%, about or up to about 85%, about or up to about 80%, about or up to about 70%, about or up to about 60%, about or up to about 50%, about or up to about 40%, about or up to about 30%, about or up to about 20%, about or up to about 15%, about or up to about 10%, about or up to about 9%, about or up to about 8%, about or up to about 7%, about or up to about 6%, about or up to about 5%, about or up to about 4%, about or up to about 3%, about or up to about 2%, about or up to about 1 %, about or up to about 0.5%, about or up to about 0.2%, about or up to about 0.1 %, about or up to about 0.01 %, or about or up to about 0.001% of the bounded internal volume outside of the one or more core particles.

[0412] Embodiment 74. The GROVE particle of any one of embodiments 1-66, wherein the outer shell is porous and / or discontinuous.

[0413] Embodiment 75. The GROVE particle of embodiment 74, wherein the pores and / or discontinuities comprise about or up to about 0.1%, about or up to about 1%, about or up to about 10%, or about or up to about 50% or more of a total surface area of the outer shell.

[0414] Embodiment 76. The GROVE particle of any one of preceding embodiments, wherein the GROVE particle comprises a single core particle.

[0415] Embodiment 77. The GROVE particle of any one of embodiments 1-75, wherein the GROVE particle comprises about or at least about 2 core particles, about or at least about 3 core particles, about or at least about 4 core particles, about or at least about 5 core particles, about or at least about 6 core particles, about or at least about 7 core particles, about or at least about 8 core particles, about or at least about 9 core particles, about or at least about 10 core particles, about or at least about 12 core particles, about or at least about 14 core particles, about or at least about 16 core particles, about or at least about 18 core particles, about or at least about 20 core particles, about or at least about 25 core particles.

[0416] Embodiment 78. The GROVE particle of any one of preceding embodiments, wherein the one or more core particles are configured to transition from an equilibrium position to one or more non-equilibrium positions.

[0417] Embodiment 79. The GROVE particle of embodiment 78, wherein the one or more core particles re-establishes the equilibrium position from the one or more non-equilibrium positions due to a restoring force.

[0418] Embodiment 80. The GROVE particle of embodiment 79, wherein the restoring force comprises gravity.

[0419] Embodiment 81 . The GROVE particle of embodiment 79, wherein the re-establishment of the equilibrium position (e.g., relaxation) occurs in about or less than about 1 ms, about or less than 2 ms, about or less than 3 ms, about or less than 4 ms, about or less than 5 ms, about or less than 6 ms, about or less than 7 ms, about or less than 8 ms, about or less than 9 ms, about or less than 10 ms, about or less than 12 ms, about or less than 14 ms, about or less than 16 ms, about or less than 18 ms, about or less than 20 ms, about or less than 25 ms, about or less than 30 ms, about or less than 35 ms, about or less than 40 ms, about or less than 45 ms, about or less than 50 ms, about or less than 55 ms, about or less than 60 ms, about or less than 65 ms, about or less than 70 ms, about or less than 75 ms, about or less than 80 ms, about or less than 85 ms, about or less than 90 ms, about or less than 95 ms, about or less than 100 ms,about or less than 125 ms, about or less than 150 ms, about or less than 175 ms, about or less than 200 ms, about or less than 250 ms, about or less than 300 ms, about or less than 350 ms, about or less than 350 ms, about or less than 400 ms, about or less than 450 ms, about or less than 500 ms, about or less than 600 ms, about or less than 700 ms, about or less than 800 ms, about or less than 900 ms, about or less than 1 s, about or less than 2 s, about or less than 3 s, about or less than 4 s, about or less than 5 s, about or less than 6 s, about or less than 7 s, about or less than 8 s, about or less than 9 s, about or less than 10 s, about or less than 20 s, about or less than 30 s, about or less than 40 s, about or less than 50 s, or about or less than 1 min.

[0420] Embodiment 82. The GROVE particle of any one of preceding embodiments, wherein the GROVE particle and / or one or more core particles comprise a shape substantially similar to one or more of a truncated teardrop shape, champagne flute shape, wine glass shape, round-bottomed shape, tumbler shape, egg-shape, paraboloid, prolate hemispheroid, oblate hemispheroid, hemispherical, elliptical, cylindrical, trigonal pyramid, pentagonal pyramid, hexagonal pyramid, a regular polygonal shape with a truncated portion, a truncated square pyramid, a truncated cone, and a truncated cone where the top plane and bottom plane are not parallel.

[0421] Embodiment 83. The GROVE particle of any one of preceding embodiments, wherein of the at least two materials of distinct density, a denser material occupies less volume of the one or more core particles than a less dense material.

[0422] Embodiment 84. The GROVE particle of any one of preceding embodiments, wherein of the at least two materials of distinct density a less dense material occupies about or at least about 1 %, 2% 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12% 14%, 16%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, or more than 90% of the one or more core particles.

[0423] Embodiment 85. The GROVE particle of any one of preceding embodiments, wherein of the at least two materials of distinct density a denser material occupies about or at least about 1 %, 2% 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12% 14%, 16%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 60%, 70%, 80%, 90%, or more than 90% of the one or more core particles.

[0424] Embodiment 86. The GROVE particle of any one of preceding embodiments, wherein the GROVE particle, the one or more core particles, and / or the outer shell comprise a shape having one or more axes of symmetry.

[0425] Embodiment 87. The GROVE particle of any one of preceding embodiments, wherein the GROVE particle, the one or more core particles, and / or the outer shell comprise an asymmetrical shape.

[0426] Embodiment 88. The GROVE particle of any one of preceding embodiments, wherein an outer and / or inner surface of the outer shell and / or an outer surface of the one or more particles comprises one or more roughness features.

[0427] Embodiment 89. The GROVE particle of embodiment 88, wherein the one or more roughness features is a variation in a surface smoothness that alters the degree of reflectivity and / or scattering of the surface at one or more wavelengths.

[0428] Embodiment 90. The GROVE particle of embodiment 88 or 89, wherein the one or more roughness features is regularly or irregularly shaped.

[0429] Embodiment 91 . The GROVE particle of embodiment 87-89, wherein the one or more roughness features appears in a regular and / or irregular pattern.

[0430] Embodiment 92. The GROVE particle of any one of preceding embodiments, wherein the one or more core particles and / or the outer shell is coated with one or more coating materials; and / or wherein the one or more coating materials is or comprises a chemical functionalization covering at least a portion of the outer shell; and / or wherein the one or more coating materials is or comprises a swellable material covering the core particle.

[0431] Embodiment 93. The GROVE particle of embodiment 92, wherein the one or more coating materials comprises one or more organic substance, inorganic substance, biological substance, and combinations thereof.

[0432] Embodiment 94. The GROVE particle of embodiment 92 or 93, wherein the one or more coating materials comprises one or more of a lubricant, surface treatment, and polishing agent.

[0433] Embodiment 95. The GROVE particle of embodiment 94, wherein the one or more lubricant, surface treatment, and polishing agent comprises one or more of polytetrafluoroethylene (PTFE), hydroxylated self-assembled monolayers, vitreous enamel, ceria (cerium oxide), ceramics, anodized metals, and silica.

[0434] Embodiment 96. The GROVE particle of any one of the preceding embodiments, wherein the core particle is suspended or otherwise shares an internal volume with a fluid or liquid.

[0435] Embodiment 97. The GROVE particle of any one of the preceding embodiments, wherein the force comprises one or more of gravity, a mechanical force, an acoustic force, a magnetic force, an electrical field, and combinations thereof.

[0436] Embodiment 98. The GROVE particle of embodiment 97, wherein the acoustic force comprises a sound having a frequency or range of frequencies comprising a range of <20 Hz range, a range of about or at least about 20 Hz to about or at least about 20,000 Hz (20 kHz), and / or in a range of about or at least about 20 kHz to about or at least about 200,000,000 Hz (200 MHz).

[0437] Embodiment 99. The GROVE particle of embodiment 98, wherein the frequency or range of frequencies is about or at least about 10 Hz, about or at least abou...

Claims

CLAIMSWhat is claimed is:1 . A gravity responsive optically variable encapsulated (GROVE) particle comprising:(i) one or more core particles comprising at least two materials of distinct density;(ii) at least two optically active agents; and(iii) an outer shell at least partially encapsulating the one or more core particles and configured to confine the one or more core particles, wherein at least a portion of the outer shell is optically transparent to at least a portion of electromagnetic radiation between frequencies of about 10 nm to about 10 cm; and wherein the one or more core particles is configured to move as a function of exposure to a force and the GROVE particle exhibits a change in an optical property as a function of the movement.

2. The GROVE particle of claim 1, wherein the one or more optically active agents exhibits a color in the visible electromagnetic spectrum and / or comprising an extinction, reflection, or scattering at a wavelength from about or at least about 300 nm to about or at least about 1200 nm; and / or wherein the change in optical property is a discernable optical effect within the visible spectrum, optionally from about 380 nm to about 750 nm.

3. The GROVE particle of claim 1 or 2, wherein the outer shell comprises a dimension of about or at least 10 nm, about or at least 20 nm, about or at least about 30 nm, about or at least about 40 nm, about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or at least about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, or about or at least about 1 pm.

4. The GROVE particle of claims 1-3, wherein the one or more core particles comprises a dimension of about or at least about 50 nm, about or at least about 60 nm, about or at least about 70 nm, about or at least about 80 nm, about or at least about 90 nm, about or at least about 100 nm, about or atleast about 150 nm, about or at least about 200 nm, about or at least about 250 nm, about or at least about 300 nm, about or at least about 350 nm, about or at least about 400 nm, about or at least about 450 nm, about or at least about 500 nm, about or at least about 550 nm, about or at least about 600 nm, about or at least about 650 nm, about or at least about 700 nm, about or at least about 750 nm, about or at least about 800 nm, about or at least about 850 nm, about or at least about 900 nm, about or at least about 950 nm, about or at least about 1000 nm (1 pm), about or at least about 2 pm, about or at least about 3 pm, about or at least about 4 pm, about or at least about 5 pm, about or at least about 6 pm, about or at least about 7 pm, about or at least about 8 pm, about or at least about 9 pm, about or at least about 10 pm, about or at least about 20 pm, or about or at least about 50 pm.

5. The GROVE particle of any one of the preceding claims, wherein the optically active agents are disposed on, or incorporated into, the one or more core particles, and / or wherein the one or more core particles comprises materials which are optically active agents.

6. The GROVE particle of any one of the preceding claims, wherein the at least two materials comprise one or more of metals, metal oxides, metal nitrides, inorganic materials, silica, organic materials, organic polymers, inorganic polymers, biological polymers, synthetic polymers, and combinations thereof.

7. The GROVE particle of any one of the preceding claims, wherein the one or more core particles comprises two optically active agents, three optically active agents, four optically active agents, or five or more optically active agents.

8. The GROVE particle of any one of the preceding claims, wherein the change in optical property is a change in the color, wherein the color is one or more of white, black, red, orange, yellow, green, blue, indigo, and violet, or a color shade or hue therebetween.

9. The GROVE particle of any one of the preceding claims, wherein the one or more optically active agents comprises one or more dye, pigment, and / or special optical material.

10. The GROVE particle of claim 9, wherein the one or more dye, pigment, and / or special optical material comprises one or more of a transparent effect pigment, goniochromatic pigment, pearlescent pigment, metallic pigment, interference pigment, metallic effect pigment, fluorescentpigment, luminescent pigment, phosphorescent pigment, magnetic pigment, anticorrosive pigment, anisotropic material, and / or plasmonic material; optionally wherein the metallic pigment comprises one or more of aluminum, bronze, and copper metallic pigment; optionally wherein the pearlescent pigment comprises one or more of mica, titanium dioxide, and bismuth oxychloride; optionally wherein the fluorescent pigment comprises one or more fluorescent dye and pigment comprising a fluorescent mineral; optionally wherein the phosphorescent pigment comprises zinc sulfide and / or strontium aluminate; optionally wherein the interference pigment comprises titanium dioxide-coated mica and / or aluminum oxide-coated mica; optionally wherein the anisotropic material comprises a nanoparticle of the one or more metals, optionally comprising a nanorod of one or more of gold (Au), silver (Au), and aluminum (Al); optionally wherein the plasmonic material comprises a pigment, particle, foil, and / or film, further optionally wherein the film comprises a polymer-film loaded with noble metal nanoparticles; and optionally wherein the goniochromatic pigment comprises aluminum coated with magnesium fluoride embedded in chromium;11. The GROVE particle of any one of the preceding claims, wherein at least one of the at least two materials comprise a magnetic material.

12. The GROVE particle of claim 11, wherein the magnetic material is ferromagnetic, ferrimagnetic, antiferromagnetic, diamagnetic, paramagnetic, superparamagnetic, and / or antiferromagnetic.

13. The GROVE particle of claim 11 or 12, wherein the magnetic material comprises one or more of an inorganic, organic, carbon-based, or biomolecule-based magnetic material.

14. The GROVE particle of any one of the preceding claims, wherein the at least two materials, the optically active agents, and / or the outer shell is or comprises a polymeric material.

15. The GROVE particle of any one of the preceding claims, wherein the at least two materials, the optically active agents, and / or the outer shell is or comprises silica (SiO2).

16. The GROVE particle of any one of the preceding claims, wherein the outer shell comprises one or more materials, one or more layers, and / or comprises a single, uniform thickness and / or varying thicknesses.

17. The GROVE particle of any one of the preceding claims, wherein the outer shell comprises at least a portion that is opaque and / or is configured to filter or select for a wavelength or ranges of wavelengths of radiation.

18. The GROVE particle of any one of the preceding claims, wherein the one or more core particles comprises a Janus particle.

19. The GROVE particle of any one of the preceding claims, wherein the outer shell fully encapsulates the core particle, resulting in a bounded internal volume.

20. The GROVE particle of claim 19, wherein the bounded internal volume comprises one or more of a gas or mixture of gases, a liquid or mixture of liquids, a polymer or mixture of polymers, a semisolid, and a solid material.

21. The GROVE particle of any one of claims 1-18, wherein the outer shell is porous and / or discontinuous.

22. The GROVE particle of any one of the preceding claims, wherein the GROVE particle comprises a single core particle.

23. The GROVE particle of any one of claims 1 -21 , wherein the GROVE particle comprises about or at least about 2 core particles, about or at least about 3 core particles, about or at least about 4 core particles, about or at least about 5 core particles, about or at least about 6 core particles, about or at least about 7 core particles, about or at least about 8 core particles, about or at least about 9 core particles, or about or at least about 10 core particles.

24. The GROVE particle of any one of the preceding claims, wherein the one or more core particles are configured to transition from an equilibrium position to one or more non-equilibrium positions.

25. The GROVE particle of claim 24, wherein the one or more core particles re-establishes the equilibrium position from the one or more non-equilibrium positions due to a restoring force, and wherein the restoring force comprises gravity.

26. The GROVE particle of claim 24 or 25, wherein the re-establishment of the equilibrium position (relaxation) occurs in about or less than 10 ms, about or less than 12 ms, about or less than 14 ms, about or less than 16 ms, about or less than 18 ms, about or less than 20 ms, about or less than 25 ms, about or less than 30 ms, about or less than 35 ms, about or less than 40 ms, about or less than 45 ms, about or less than 50 ms, about or less than 55 ms, about or less than 60 ms, about or less than 65 ms, about or less than 70 ms, about or less than 75 ms, about or less than 80 ms, about or less than 85 ms, about or less than 90 ms, about or less than 95 ms, about or less than 100 ms, about or less than 125 ms, about or less than 150 ms, about or less than 175 ms, about or less than 200 ms, about or less than 250 ms, about or less than 300 ms, about or less than 350 ms, about or less than 350 ms, about or less than 400 ms, about or less than 450 ms, about or less than 500 ms, about or less than 600 ms, about or less than 700 ms, about or less than 800 ms, about or less than 900 ms, about or less than 1 s, about or less than 2 s, about or less than 3 s, about or less than 4 s, about or less than 5 s.

27. The GROVE particle of any one of the preceding claims, wherein an outer and / or inner surface of the outer shell and / or an outer surface of the one or more particles comprises one or more roughness features.

28. The GROVE particle of any one of the preceding claims, wherein the one or more core particles and / or the outer shell is coated with one or more coating materials; and / or wherein the one or more coating materials is or comprises a chemical functionalization covering at least a portion of the outer shell; and / or wherein the one or more coating materials is or comprises a swellable material covering the core particle.

29. The GROVE particle of claim 28, wherein the one or more coating materials comprises one or more organic substance, inorganic substance, biological substance, and combinations thereof.

30. The GROVE particle of any one of the preceding claims, wherein the core particle is suspended or otherwise shares an internal volume with a fluid or liquid.

31. The GROVE particle of any one of the preceding claims, wherein the force comprises one or more of gravity, a mechanical force, an acoustic force (sound), a magnetic force (magnetic field / flux), an electrical field, and combinations thereof.

32. The GROVE particle of claim 31 , wherein the acoustic force comprises a sound having a frequency or range of frequencies comprising <20 Hz range, a range of about or at least about 20 Hz to about or at least about 20,000 Hz (20 kHz), and / or a range of about or at least about 20 kHz to about or at least about 200,000,000 Hz (200 MHz); and / or wherein the acoustic force comprises an intensity of about 0.25 decibels (dB) to about or at least about 150 dB; and / or wherein the acoustic force comprises a duration of about 0.01 second (s) to about or at least 2.0 seconds; and / or wherein the acoustic force comprises a distance from a GROVE particle of about 0.0001 m to about or at least about 0.5 m.

33. The GROVE particle of any one of the preceding claims, wherein the one or more core particles comprise a magnetic material and the one or more core particles move as a function of exposure to a magnetic force, and a restoring force comprising gravity.

34. A composition comprising gravity-responsive optically-variable encapsulated (GROVE) particles of any one of claims 1-33.

35. The composition of claim 34, wherein the GROVE particles are suspended in a liquid.

36. The composition of claim 34 or 35, wherein the GROVE particles are present in a concentration of about or less than about 0.001 % (w / v), about or less than about 0.1 % (w / v), about or less than about 0.5% (w / v), about or less than about 1 % (w / v), about or less than about 2% (w / v), about or less than about 3% (w / v), about or less than about 4% (w / v), about or less than about 5% (w / v), about or less than about 6% (w / v), about or less than about 7% (w / v), about or less than about 8% (w / v), about or less than about 9% (w / v), about or less than about 10% (w / v), about or less than about 12% (w / v), about or less than about 14% (w / v), about or less than about 16% (w / v), about or less than about 18% (w / v), about or less than about 20% (w / v), about or less than about 25% (w / v), about or less than about 30% (w / v), about or less than about 35% (w / v), about or less than about 40% (w / v), about or less than about 50% (w / v), about or less than about 60% (w / v), or about or less than about 70% (w / v).

37. The composition of any one of claims 34-36, wherein the GROVE particles are arranged in an array on a substrate.

38. The composition of claim 37, wherein the substrate comprises a thin film, plastic, polymer, and / or paper substrate.

39. The composition of claim 37 or 38, wherein at least a portion of the substrate is transparent to at least a portion of the visible electromagnetic (EM) spectrum and / or at least a portion is opaque.

40. The composition of any one of claims 37-39, wherein the GROVE particles are disposed upon the substrate, embedded in the substrate, and / or sandwiched between two or more substrates.

41. The composition of any one of claims 34-40, wherein the GROVE particles are arranged in a plane and an optical effect is different when viewed from above the plane GROVE particles in comparison to when viewed from below the plane of GROVE particles.

42. A method of authenticating an object using a gravity-responsive optically-variable encapsulated (GROVE) particles comprising: providing an object comprising GROVE particles of any one of claims 1-33, or comprising a composition of GROVE particles of any one of claims 34-41 , wherein the object has an initial optical state; applying a force to the object and / or the GROVE particles, to cause a movement in the GROVE particles which elicits the object to present a change in one or more optical properties from the initial optical state; and detecting the change in the one or more optical properties as a function of the application of the force.

43. The method of claim 42, wherein the GROVE particles are in a formulation, wherein the formulation comprises a fluid, suspension, ink, liquid film, adhesive, and / or material thereof; a foil, film, thin plastic, paper, and / or material thereof; or a fiber, thread, yarn, twine, and / or material thereof.

44. The method of claim 42 or 43, further comprises tagging, applying, arranging, spraying, gluing, and / or weaving the GROVE particles onto the object, optionally into the shape of characters comprising letters, numerical digits, symbols, and / or images.

45. The method of any one of claims 42-44, wherein the object comprises paper, plastic, glass, metal, fabric, wood, a window, documentation, an electronic device, a computer chip, construction materials, human or animal tissue or skin, leather, luxury goods, high-value goods, hardware, computer hardware, and / or mobile phones; wherein the object comprises paper currency, bank notes, checks, and / or money orders; or wherein the object comprises documentation, tax stamps, passports, identification, government-issued documents and permits, and driver’s license.

46. The method of any one of claims 42-45, wherein the force comprises one or more of a mechanical force (shaking, agitation, jerking, tilting), gravity (reorienting the position relative to gravity), acoustic force (sound), magnetic force (magnetic field / flux), and an electrical field.

47. The method of any one of claims 42-46, wherein the change in the optical property comprises a change in one or more color in the visible electromagnetic (EM) spectrum comprising an absorption, emission, extinction, reflection, scattering, and / or interference properties at a wavelength, optionally from about 350 nm to about 800 nm; and / or wherein the one or more color comprises one or more of white, black, red, orange, yellow, green, blue, indigo, violet, or a color shade or hue therebetween48. The method of any one of claims 42-47, wherein the change in optical property is detectable by human vision, and / or wherein the change in optical property is not detectable by human vision.

49. The method of any one of claims 42-48, wherein detecting comprises measuring, observing, and / or registering an optical signal generated by the GROVE particles via one or more of a camera, human vision, radio frequency (RF) reader, barcode scanner, spectrometer, filter, window, grating, beam splitter, polarizer, collimator, birefringent element, prism, bandpass filter, aperture, or lens to detect an optical signal emanating from the object.

50. An overt authentication feature comprising one or more GROVE particles of any one of claims 1- 33.

51. A gravity-responsive optically-variable encapsulated (GROVE) particle, wherein the GROVE particle is as substantially shown in any one of Figs. 1, 2A-2E, 4A-4L, 5A-5F, 6A-6G, 7A-7F, 20A- 20G, 22A-22F, 24A-24D, 27A-27E, 28A-28E, 29A-29E, 30A-30B, 33A-33F, 34A-34G, 37, 38, 39, 40A-40D, 41A-41 B, 42A-42D, 43A-43C, 44A-44C.

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