Shape memory alloys, methods of making, and methods of use

Abstract

The present disclosure provides for shape memory alloy structures having one-way shape memory characteristics, methods of making periodic shape memory alloy nanostructures, and methods of use. The shape memory alloy structures of the present disclosure can reversibly change shape and / or coloration based upon interaction with stimuli or exposed to stimuli, such as temperature.

Description

[0001] TH Docket No.222112-2370 SHAPE MEMORY ALLOYS, METHODS OF MAKING, AND METHODS OF USE CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application entitled “SHAPE MEMORY ALLOYS, METHODS OF MAKING, AND METHODS OF USE” and having serial number 63 / 552,407, filed on February 12, 2024, which is incorporated herein by reference in its entirety. BACKGROUND Shape memory alloys (SMAs) are metallic alloys that can produce large strains (as high as 8% in polycrystalline form) when subjected to changes in temperature or stress.[1] These large strains arise from a martensitic transformation between lower and higher symmetry crystalline phases. The shape memory effect (SME) refers to an SMA that de-twins when mechanically deformed in the lower symmetry phase. Upon heating, the lower symmetry phase transforms to a higher symmetry phase recovering the accumulated strain. Furthermore, if internal stresses bias the reverse transformation during cooling back to the lower symmetry phase, then strains can also be associated with this reverse transformation, a phenomenon called the two-way shape memory effect (TWSME). The large strain recovery (e.g., 8%) associated with the SME in these alloys can occur against large stresses (e.g., 500 MPa), resulting in their use as actuators. Once the temperature returns to the initial level, the new higher symmetry phase is no longer stable and reverts to the original phase. This original phase deforms easily by detwinning and hence an external force (e.g., bias spring) can be used to construct a shape memory actuator switch. The superelastic effect (SE) is a result of the same phase transformation but does not involve a temperature change to cause the phase transformation. On the other hand, the application and removal of stress causes a phase transformation which again is associated with large strains. For example, upon application of stress, strains of up to 8% are generated during the stress-induced transformation of the higher symmetry phase to the lower symmetry phase. Upon removal of the applied stress, the strain recovers during the reverse transformation to the higher symmetry phase. SUMMARY The present disclosure provides for shape memory alloy structures having one-way shape memory characteristics, methods of making periodic shape memory alloy nanostructures, and methods of use. TH Docket No.222112-2370 In an aspect, the present disclosure provides for a material, comprising: a shape memory metallic alloy structure, wherein the shape memory metallic alloy structure has a first state and a second state, wherein in the first state the shape memory metallic alloy structure has a first side having a surface grating with a periodic nanostructure or microstructure pattern, wherein in the first state the shape memory metallic alloy structure is in a first crystalline phase, wherein in the second state the shape memory metallic alloy structure has a substantially smooth or smooth surface, wherein in the second state the shape memory metallic alloy structure is in a second crystalline phase, wherein the shape memory metallic alloy structure has the characteristic of changing from the first crystalline phase of the first state to the second crystalline phase of the second state by increasing the temperature of the shape memory metallic alloy structure to a transition temperature of the shape memory metallic alloy or higher, wherein the shape memory metallic alloy structure has the characteristic of changing from the second crystalline phase of the second state to the first crystalline phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to the transition temperature of the shape memory metallic alloy or lower. In an aspect, the present disclosure provides for a method of making the material as provided above or herein, comprising: disposing a monolayer of particles on a first substrate, wherein the particles form a periodic particle pattern; disposing of a shape memory metallic alloy structure on a side of the monolayer of particles that is opposite the first structure, wherein the monolayer of particles is between the first substrate and the shape memory metallic alloy structure; disposing a second substrate on the shape memory metallic alloy structure on the side opposite the monolayer of particles to form a sandwich structure; and applying a pressure upon the sandwich structure sufficient to form a surface grating with periodic nanostructure or microstructure pattern into the shape memory metallic alloy structure. In an aspect, the present disclosure provides for a method of making the material as described above or herein, comprising: disposing a monolayer of particles on a first substrate, wherein the particles form a periodic particle pattern; disposing of a shape memory metallic alloy on a side of the monolayer of particles that is opposite the first structure to form a shape memory metallic alloy structure, wherein the monolayer of particles is between the first substrate and the shape memory metallic alloy structure, wherein the shape memory metallic alloy structure has a surface grating with periodic nanostructure or microstructure pattern. TH Docket No.222112-2370 BRIEF DESCRIPTION OF THE DRAWINGS Aspects of the present disclosure can be better understood with reference to the following drawings. It is noted that the elements in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the embodiments. In the drawings, like reference numerals designate like or corresponding, but not necessarily the same, elements throughout the several views. Figures 1A-1F illustrates the typical programming and recovery cycle of a NiTi SMA sheet. Photos of a NiTi SMA sheet at original flat status (Figure 1A), the same NiTi sample after mechanical indentation (Figure 1B), and the SMA sheet after thermal recovery (Figure 1C). SEM images of the original flat SMA sheet (Figure 1D), mechanically indented state (Figure 1E), and thermally recovered state (Figure 1F). Figures 2A-2D illustrate the sputtered NiTi SMA film on a self-assembled monolayer silica colloidal crystal. Photo of a sputtered NiTi film on 1 μm silica particles (Figure 2A), SEM images of the sputtered film at 90° view angle (Figure 2B), bottom view (Figure 2C), and top view (Figure 2D). Figures 3A and 3B illustrates normal-incidence optical reflection measurements of a NiTi SMA sheet before indentation, after indented with circular dimples of 510 nm depth, and after thermal recovery in the visible (Figure 3A) and NIR range (Figure 3B). Figures 4A and4B illustrate normal-incidence optical reflection measurements of sputtered NiTi SMA film on 1 μm silica colloidal crystal film in the visible (Figure 4A) and NIR range (Figure 4B). Figures 5A and 5B illustrate X-ray diffraction spectra show characteristic diffraction peaks for NiTi alloy sheet (Figure 5A) and sputtered NiTi film (Figure 5B). DETAILED DESCIPTION The present disclosure provides for shape memory alloy structures having one-way shape memory characteristics, methods of making periodic shape memory alloy nanostructures, and methods of use. Before the present disclosure is described in greater detail, it is to be understood that this disclosure is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims. TH Docket No.222112-2370 Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit (unless the context clearly dictates otherwise), between the upper and lower limit of that range, and any other stated or intervening value in that stated range, is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure. Any recited method can be carried out in the order of events recited or in any other order that is logically possible. Embodiments of the present disclosure will employ, unless otherwise indicated, techniques of chemistry, inorganic chemistry, material science, and the like, which are within the skill of the art. Such techniques are explained fully in the literature. The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to perform the methods and use the compositions and compounds disclosed and claimed herein. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C, and pressure is in atmosphere. Standard temperature and pressure are defined as 25 °C and 1 atmosphere. Before the embodiments of the present disclosure are described in detail, it is to be understood that, unless otherwise indicated, the present disclosure is not limited to particular materials, reagents, reaction materials, manufacturing processes, or the like, as such can vary. It is also to be understood that the terminology used herein is for purposes of describing particular embodiments only, and is not intended to be limiting. It is also possible in the TH Docket No.222112-2370 present disclosure that steps can be executed in different sequence where this is logically possible. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a support” includes a plurality of supports. In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings unless a contrary intention is apparent. Discussion Embodiments of the present disclosure provide for shape memory alloy structures having one-way shape memory characteristics, methods of making periodic shape memory alloy nanostructures, and methods of use. In an aspect, the shape memory alloy structures of the present disclosure can reversibly change shape and / or coloration based upon interaction with stimuli or exposed to stimuli, such as temperature. An advantage of an embodiment of the present disclosure is that the shape memory alloy nanostructures are simple to make, scalable, and inexpensive. Surface gratings with periodic nano / micro-structures patterned directly on shape memory alloys have been successfully fabricated using methods of the present disclosure (e.g., using an indentation method or a colloidal templating approach). Embodiments of the present disclosure can be used in applications such as aircraft and spacecraft, automotive, robotics, dentistry, optometry, integrated nanooptics, heat pumps, and the like. In an aspect, the shape memory alloy structures can be used in optoelectronic devices, such as tunable optical filters and mirrors, light emitting diodes, plasmonic biosensors, and tunable lasers. Shape memory alloys are a class of "smart" materials that can memorize and recover their permanent shapes in response to an external stimulus, such as temperature change (e.g., heat), light, solvent, electricity, and magnetic fields. In an embodiment, the shape memory alloy structures have shape memory characteristics and tunable light diffraction properties. In an aspect, the diffraction properties can be selected based on the periodic particle pattern (e.g., periodic nanostructure or microstructure pattern) of the shape memory alloy structure. In one state the shape memory alloy structure has a periodic particle pattern (e.g., visually this can be iridescent) and in another state the shape memory alloy structure does not have the periodic particle pattern (e.g., visually a dull metallic color and is not iridescent), where the shape memory alloy structure has the characteristic to change between states by changing the temperature of the shape memory alloy structure (e.g., above or below the Martensite TH Docket No.222112-2370 temperature of the shape memory alloy). In particular, embodiments of the present disclosure provide shape memory alloy structures that have thermoresponsive one-way shape memory effect (OWSME) and superelastic effect (SE) properties. The present disclosure provides for a material that includes a shape memory metallic alloy structure. The shape memory metallic alloy is selected from the group consisting of: nickel-titanium based alloy (e.g., NiTi), indium-titanium based alloy, nickel-aluminum based alloy, nickel-gallium based alloy, copper based alloy, gold-cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy. In an aspect, the shape memory metallic alloy is a nickel-titanium based alloy. The shape memory metallic alloy structure can take the form of a square or rectangular sheet or other polygonal shape or a wire shape or a shape as needed for a particular technical application. The shape memory metallic alloy structure can have a longest diameter (e.g., length, width, radius) of about 1 cm to 1 m. In an aspect, the thickness of the shape memory metallic alloy structure can be about 1 micrometer to 10 centimeters. The shape memory metallic alloy structure has a first state and a second state. In an aspect, in the first state, the shape memory metallic alloy structure is iridescent. In an aspect, in the second state, the shape memory metallic alloy structure is not iridescent (e.g., a gray or metal color, a dual metal color, or achromatic color). The shape memory metallic alloy structure has a first side having a surface grating with a periodic nanostructure or microstructure pattern. The first state of the shape memory metallic alloy structure has a first crystalline phase (e.g., a Martensite crystalline phase for nickel- titanium based alloy). The second state of the shape memory metallic alloy structure has a substantially smooth or smooth surface (e.g., without the periodic nanostructure or microstructure pattern or substantially (e.g., about 85% or more, about 90% or more, about 95% or more) without the periodic nanostructure or microstructure pattern). The second state of the shape memory metallic alloy structure has a second crystalline phase (e.g., an Austenite crystalline phase for nickel-titanium based alloy). The shape memory metallic alloy structure has the characteristic of changing from the first crystalline phase of the first state to the second crystalline phase of the second state by increasing the temperature of the shape memory metallic alloy structure to a transition temperature (e.g., Martensite temperature for nickel- titanium based alloy (e.g., about 40° C for a specific alloy sample) of the shape memory metallic alloy or higher. When the shape memory metallic alloy structure is made of NiTi, the TH Docket No.222112-2370 shape memory metallic alloy structure has the characteristic of changing from the Martensite crystalline phase of the first state to the Austenite crystalline phase of the second state by increasing the temperature of the shape memory metallic alloy structure to the Martensite temperature (e.g., 40° C) of the shape memory metallic alloy or higher. Similarly, the shape memory metallic alloy structure has the characteristic of changing from the second crystalline phase of the second state to the first crystalline phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to the transition temperature (e.g., Martensite temperature) of the shape memory metallic alloy or lower. The shape memory metallic alloy structure has the characteristic of changing from the second crystalline phase of the second state to the first crystalline phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to the transition temperature (e.g., Martensite temperature) of the shape memory metallic alloy or lower. In an embodiment, the shape memory metallic alloy is a nickel-titanium based alloy and the change from a first state to a second state is based on the ability of nickel-titanium based alloy (e.g., Nitinol) to transform from a higher temperature crystal structure (Austinite crystalline phase) to a different lower temperature crystal structure (Martensite crystalline phase), where the transition temperature (e.g., Martensite temperature) is about 40° C or 40° C. In particular, the shape memory metallic alloy structure has the characteristic of changing from the Martensite crystalline phase of the first state to the Austenite crystalline phase of the second state by increasing the temperature of the shape memory metallic alloy structure to about 40° C or higher, 40° C or higher, higher than 40° C, or higher than 41° C. And the shape memory metallic alloy structure has the characteristic of changing from the Austenite crystalline phase of the second state to the Martensite crystalline phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to about 40° C or lower, 40° C or lower, lower than 40° C, or 39° C or lower. In an aspect, the surface grating with periodic nanostructure or microstructure pattern can be formed by indentions from ordered arrays of silica nanoparticles or microparticles. In an embodiment, the nanoparticles or microparticles can have a uniform diameter or in another embodiment the nanoparticles or microparticles can be of various different (non-uniform) diameters. The nanoparticles or microparticles can have a diameter is about 100 nm to 100 µm, about 100 nm to 2 µm, about 500 nm to 1 µm, about 500 nm to 4 µm, about 1 µm to 100 µm, or about 2 µm to 100 µm. Additional details will be provided herein. In an aspect, the surface grating with periodic nanostructure or microstructure pattern includes a plurality of hemispherical three-dimensional impressions in the shape memory TH Docket No.222112-2370 metallic alloy. The distance between pairs of the hemispherical three-dimensional impressions in a group of the hemispherical three-dimensional impressions is substantially the same to form the periodic spacing. The surface of the shape memory metallic alloy can have about 30% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more of the surface being the surface grating with periodic nanostructure or microstructure pattern. In an aspect, a distance across the hemispherical three-dimensional impression at the top (e.g., the original planar surface of the structure) of the hemispherical three-dimensional impression can be about 100 nm to 100 µm, about 100 nm to 2 µm, about 500 nm to 1 µm, about 500 nm to 4 µm, about 1 µm to 100 µm, or about 2 µm to 100 µm. In an aspect, a depth of the hemispherical three-dimensional impression can be about 20 nm to 40 µm, about 100 nm to 40 µm, about 100 nm to 2 µm, about 500 nm to 1 µm, about 500 nm to 40 µm, about 1 µm to 40 µm, or about 2 µm to 40 µm. The present disclosure provides for methods of making the shape memory metallic alloy structure. In an aspect, the method includes disposing a monolayer of particles (e.g., silica nanoparticle and / or microparticles) on a first substrate. The particles form a periodic particle pattern. The method includes disposing of a shape memory metallic alloy structure on a side of the monolayer of particles that is opposite the first structure. The monolayer of particles is between the first substrate and the shape memory metallic alloy structure. The method then includes disposing a second substrate on the shape memory metallic alloy structure on the side opposite the monolayer of particles to form a sandwich structure. Thereafter, a pressure is applied upon the sandwich structure sufficient to form a surface grating with periodic nanostructure or microstructure pattern into the shape memory metallic alloy structure. The pressure can be applied using a press. The pressure can be about 1 lb force to 20,000 lb force. In an aspect, the first substrate and the second substate can be glass substrates (e.g., glass slides). In other aspect, the first substrate and the second substate can be formed of other materials such as metal, metal oxide, semiconductor, and the like, where the material can withstand the pressure applied to the sandwich structure. The shape memory metallic alloy structure can have dimensions as described above. The shape memory metallic alloy structure can be made of a shape memory metallic alloy as described above. The surface grating with periodic nanostructure or microstructure pattern can include a plurality of hemispherical three-dimensional impressions in the shape memory metallic alloy such as described above and herein. TH Docket No.222112-2370 The particles can be nanoparticles or microparticles. The particle can be made of a material such as a silica nanoparticle, a polymer latex particle, a titania particle, a zirconia particle, an alumina particle, a gold particle, an iron oxide particle, or a CdSe particle. The particles can have a uniform diameter or a mix of diameters, where the mix of diameters can form a periodic particle pattern. The particles can have a diameter of about 50 nm to 100 µm, about 500 nm to 4 µm, about 500 nm to 3 µm, about 500 nm to 2 µm, about 200 nm to 1000 nm, or about 200 to 500 nm. In an embodiment, the particles can be silica particles. The monodispersed silica particles can be synthesized by the standard Stöber method or other appropriate method. Silica particles are self-assembled on a substrate such as a glass microslide. Other monodispersed particles, such as polystyrene and poly(methyl methacrylate) (PMMA) particles, can also be used. Silica particles can be dispersed in an alcohol such as ethanol, can be assembled on the glass slides. The silica nanoparticles assembled by various methodologies, such as spin coating, dip coating, doctor blade coating, convective self-assembly, and so on. In an embodiment, the silica nanoparticles can be self-assembled or not be self-assembled and / or possess long-range ordering. The silica nanoparticle monolayers can be created by a variety of methods, for example, a simple and scalable Langmuir-Blodgett (LB) method. In another aspect, the present disclosure provides for a method of making the shape memory metallic alloy structure that includes disposing a monolayer of particles on a first substrate. The particles form a periodic particle pattern. The method provides for disposing a shape memory metallic alloy on a side of the monolayer of particles that is opposite the first structure to form a shape memory metallic alloy structure. The monolayer of particles is between the first substrate and the shape memory metallic alloy structure. The shape memory metallic alloy structure has a surface grating with periodic nanostructure or microstructure pattern, such as that described herein. The first substrate is a glass substrate or made of another material as described herein. The shape memory metallic alloy structure can be made of a shape memory metallic alloy as described herein. The shape memory metallic alloy structure can have dimensions as described above. The shape memory metallic alloy structure can be made of shape memory metallic alloys as described above. The surface grating with periodic nanostructure or microstructure pattern can include a plurality of hemispherical three-dimensional impressions in the shape memory metallic alloy such as described above and herein. The particles can be nanoparticles or microparticles as described above and herein. TH Docket No.222112-2370 In an embodiment, the distance between at least two pairs of adjacent particles (or hemispherical three-dimensional impressions) can be substantially the same (e.g., about 100 nm to 1000 nm). In an embodiment, the number of unique pairs can be about 10, 100, 1000, 10,000, 100,000, 1,000,000, 100,000,000, 100,000,000, to about 10, 100, 1000, 10,000, 100,000, 1,000,000, 100,000,000, 100,000,000, 1 x 1010, 1 x 1012, 1 x 1015, 1 x 1017, or 1 x 1020and any set of ranges (e.g., about 10,000 to 100,000, about 100 to 1 x 1010, etc.) within these numbers or subranges (e.g., about 15 to 200,000, 2,500,000 to 3 x 1012, etc.) within these numbers. In an embodiment, the distance between each pair of adjacent particles (or hemispherical three-dimensional impressions) is substantially the same. In an embodiment, the distance between a portion of the pairs of adjacent particles (or hemispherical three- dimensional impressions) is substantially the same. In an embodiment, the “portion” can be about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 99% or more, or about 100%, over a defined area of the substrate (e.g., shape memory metallic alloy structure). In an embodiment, the defined area can include about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 95% or more, about 99% or more, or about 100%, of the area of the substrate (e.g., shape memory metallic alloy structure). The term “substantially” in these contexts can mean about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 99% or more, or about 100%. The term “adjacent” refers to two particles (or hemispherical three-dimensional impressions) next to one another without a particle (or hemispherical three-dimensional impressions) separating them in the same substrate (e.g., shape memory metallic alloy structure). In an embodiment, a polymer framework separates the particles (or hemispherical three-dimensional impressions). In an embodiment, the diameter (or longest distance across the void) of all or substantially all of the particles (or hemispherical three-dimensional impressions) can be substantially equivalent. The term “substantially” in this context can mean about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, about 99% or more, or about 100%. Now having described various aspects of the present disclosure, additional features are provided. Feature 1. A material, comprising: a shape memory metallic alloy structure, wherein the shape memory metallic alloy structure has a first state and a second state, wherein in the first state the shape memory metallic alloy structure has a first side having a surface grating with a TH Docket No.222112-2370 periodic nanostructure or microstructure pattern, wherein in the first state the shape memory metallic alloy structure is in a first crystalline phase, wherein in the second state the shape memory metallic alloy structure has a substantially smooth or smooth surface, wherein in the second state the shape memory metallic alloy structure is in a second crystalline phase, wherein the shape memory metallic alloy structure has the characteristic of changing from the first crystalline phase of the first state to the second crystalline phase of the second state by increasing the temperature of the shape memory metallic alloy structure to a transition temperature of the shape memory metallic alloy or higher, wherein the shape memory metallic alloy structure has the characteristic of changing from the second crystalline phase of the second state to the first crystalline phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to the transition temperature of the shape memory metallic alloy or lower. Feature 2. The material of any of the features described above or herein, wherein in the first state, the shape memory metallic alloy structure is iridescent, wherein in the second state, the shape memory metallic alloy structure is not iridescent. Feature 3. The material of any of the features described above or herein, wherein the shape memory metallic alloy is selected from the group consisting of: nickel-titanium based alloy, indium-titanium based alloy, nickel-aluminum based alloy, nickel-gallium based alloy, copper based alloy, gold-cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy. Feature 4. The material of any of the features described above or herein, wherein the surface grating with periodic nanostructure or microstructure pattern is formed by indentions from nanoparticles or microparticles, wherein the nanoparticles or microparticles have a uniform diameter, wherein the diameter is about 100 nm to 100 µm. Feature 5. The material of any of the features described above or herein, wherein the surface grating with periodic nanostructure or microstructure pattern is a plurality of hemispherical three dimensional impressions in the shape memory metallic alloy, wherein a distance between pairs of the hemispherical three dimensional impressions in a group of the hemispherical three dimensional impressions is substantially the same, wherein a distance across the hemispherical three dimensional impression at the top of the hemispherical three dimensional impression is about 100 nm to 100 µm, wherein a depth of the hemispherical three dimensional impression is about 20 to 20 µm. Feature 6. The material of any of the features described above or herein, wherein the shape memory metallic alloy structure has a length of about 1 cm to 1 m, a width of about 1 cm to 1 m, or a diameter of about 1 cm to 1 m; and wherein the shape memory TH Docket No.222112-2370 metallic alloy structure has a thickness of about 1 µm to 10 cm. Feature 7. The material of any of the features described above or herein, wherein the shape memory metallic alloy is selected from the group consisting of: nickel-titanium based alloy; wherein the shape memory metallic alloy structure has the characteristic of changing from the Martensite phase of the first state to the Austenite phase of the second state by increasing the temperature of the shape memory metallic alloy structure to 40° C or higher or higher than 40° C, wherein the shape memory metallic alloy structure has the characteristic of changing from the Austenite phase of the second state to the Martensite phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to 40° C or lower or lower than 40° C. Feature 8. A method of making the material of as described above or herein, comprising: disposing a monolayer of particles on a first substrate, wherein the particles form a periodic particle pattern; disposing of a shape memory metallic alloy structure on a side of the monolayer of particles that is opposite the first structure, wherein the monolayer of particles is between the first substrate and the shape memory metallic alloy structure; disposing a second substrate on the shape memory metallic alloy structure on the side opposite the monolayer of particles to form a sandwich structure; and applying a pressure upon the sandwich structure sufficient to form a surface grating with periodic nanostructure or microstructure pattern into the shape memory metallic alloy structure. Feature 9. The method of any of the features described above or herein, wherein the pressure is about 1 lb force to 20,000 lb force. Feature 10. The method of any of the features described above or herein, wherein the first substrate and the second substate is glass, silicon or glass / silicon substrate. Feature 11. The method of any of the features described above or herein, wherein the shape memory metallic alloy structure is made of a shape memory metallic alloy selected from is selected from the group consisting of: nickel-titanium based alloy, indium-titanium based alloy, nickel-aluminum based alloy, nickel- gallium based alloy, copper based alloy, gold-cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy. Feature 12. The method of any of the features described above or herein, wherein the surface grating with periodic nanostructure or microstructure pattern is formed by indentions from nanoparticles or microparticles, wherein the nanoparticles or microparticles have a uniform diameter, wherein the diameter is about 100 nm to 100 µm. Feature 13. The method of any of the features described above or herein, wherein the surface grating with periodic nanostructure or microstructure pattern is a plurality of hemispherical three dimensional impressions in the shape memory metallic alloy, wherein a TH Docket No.222112-2370 distance between pairs of the hemispherical three dimensional impressions in a group of the hemispherical three dimensional impressions is substantially the same, wherein a distance across the hemispherical three dimensional impression at the top of the hemispherical three dimensional impression is about 100 nm to 100 µm, wherein a depth of the hemispherical three dimensional impression is about 20 to 20 µm. Feature 14. The method of any of the features described above or herein, wherein the shape memory metallic alloy structure has a length of about 1 cm to 1 m, a width of about 1 cm to 1 m, or a diameter of about 1 cm to 1 m; and wherein the shape memory metallic alloy structure has a thickness of about 1 µm to 10 cm. Feature 15. The method of any of the features described above or herein, wherein particle is selected from a silica nanoparticle, a polymer latex particle, a titania particle, a zirconia particle, an alumina particle, a gold particle, an iron oxide particle, a CdSe particle, optionally wherein the particles where the type selected has a uniform diameter, optionally wherein the diameter of the particle is about 100 nm to 100 µm. Feature 16.A method of making the material as described above or herein, comprising: disposing a monolayer of particles on a first substrate, wherein the particles form a periodic particle pattern; disposing of a shape memory metallic alloy on a side of the monolayer of particles that is opposite the first structure to form a shape memory metallic alloy structure, wherein the monolayer of particles is between the first substrate and the shape memory metallic alloy structure, wherein the shape memory metallic alloy structure has a surface grating with periodic nanostructure or microstructure pattern. Feature 17. The method of any of the features described above or herein, wherein the first substrate is a glass substrate. Feature 18. The method of any of the features described above or herein, wherein the shape memory metallic alloy structure is made of a shape memory metallic alloy selected from is selected from the group consisting of: nickel-titanium based alloy, indium-titanium based alloy, nickel-aluminum based alloy, nickel-gallium based alloy, copper based alloy, gold- cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy. Feature 19. The method of any of the features described above or herein, wherein the surface grating with periodic nanostructure or microstructure pattern is formed by indentions from nanoparticles or microparticles, wherein the nanoparticles or microparticles have a uniform diameter, wherein the diameter is about 100 nm to 100 µm. Feature 20. The method of any of the features described above or herein, wherein the surface grating with periodic nanostructure or microstructure pattern is a plurality of hemispherical three dimensional impressions in the TH Docket No.222112-2370 shape memory metallic alloy, wherein a distance between pairs of the hemispherical three dimensional impressions in a group of the hemispherical three dimensional impressions is substantially the same, wherein a distance across the hemispherical three dimensional impression at the top of the hemispherical three dimensional impression is about 100 nm to 100 µm, wherein a depth of the hemispherical three dimensional impression is about 20 nm to 20 µm. Feature 21. The method of any of the features described above or herein, wherein the shape memory metallic alloy structure has a length of about 1 cm to 1 m, a width of about 1 cm to 1 m, or a diameter of about 1 cm to 1 m; and wherein the shape memory metallic alloy structure has a thickness of about 1 µm to 10 cm. Feature 22. The method of any of the features described above or herein, wherein particle is selected from a silica nanoparticle, a polymer latex particle, a titania particle, a zirconia particle, an alumina particle, a gold particle, an iron oxide particle, a CdSe particle, optionally wherein the particles where the type selected has a uniform diameter, optionally wherein the diameter of the particle is about 100 nm to 100 µm. EXAMPLES Now having described the embodiments of the disclosure, in general, the examples describe some additional embodiments. While embodiments of the present disclosure are described in connection with the example and the corresponding text and figures, there is no intent to limit embodiments of the disclosure to these descriptions. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of embodiments of the present disclosure. Example: In this disclosure, we demonstrate the fabrication and optical characterization of nanostructured shape memory alloys using simple bottom-up approaches. Surface gratings with periodic nanostructures patterned directly on shape memory alloys have been successfully fabricated by using a simple indentation method and a colloidal templating approach. The indented NiTi SMA samples were prepared by using self-assembled, closed- packed, monolayer silica colloidal crystals as a structural template. The template was made by using the simple Langmuir-Blodgett (LB) coating method,2and consisted of hexagonally closed-packed silica microspheres with different diameters ranging from 200 nm to 4 micrometers. A sandwich structure was constructed by placing a smooth NiTi SMA sheet between two glass slides with monolayer silica colloidal crystals covering their surfaces. The TH Docket No.222112-2370 sandwich structure was subsequently inserted into a manual hydraulic press (Carver Model C). The sample was then compressed with a force of 10,000 pounds to imprint the hemispherical shapes of the silica particles onto the surfaces of the NiTi sheet. After removing the sample from the hydraulic press, some silica particles may adhere on the SMA sheet. Two techniques were employed to remove the attached silica particles. The first method involves soaking the sample in a 1 vol.% hydrofluoric acid solution for ~ 1 min; while the second technique is based on wiping the particles away with wet cotton Qtips. The attached particles can be easily removed due to the low adhesion between NiTi and silica particles. In order to restore the deformed NiTi shape memory alloy with nanoscale indentation, it is necessary to heat it above its Martensite temperature of ~ 40°C. The NiTi sample is placed on a Fisher Scientific Isotemp RT digital hot plate at 60°C. It only takes 10 to 15 s for the NiTi SMA alloy to recover from the Martensite phase to the Austenite phase and return to a flat surface. The sample can be restored using heat and the process can be repeated as many times as desired. Figures 1A-1F illustrate typical photographs and scanning electron microscope (SEM) images of a NiTi SMA sheet during a mechanical indentation and thermal recovery cycle. The original metallically shining sheet (Figure 1A) with smooth surface (Figure 1D) transforms into an iridescent film (Figure 1B) caused by visible light diffraction from the indented surface gratings (Figure 1E). After a brief heat treatment, the iridescent color disappears (Figure 1C) due to the recovery of the original flat surface state (Figure 1F). In an attempt to create a nanotextured SMA film with tunable topology and examine its associated surface plasmon resonance (SPR) properties, we developed a new nanofabrication approach by sputtering nickel-titanium alloy using a commercial NiTi target over self-assembled silica monolayer colloidal crystal on a silicon wafer.3-5We coated 1 μm silica particles on a silicon wafer using the LB coating method. A KJL CMS-18 Multi-Source device was employed to deposit NiTi films using a Ni-Ti 48-52% target (99.9% pure) obtained from Testbourne. Sputtering deposition was preferred due to its potential to generate films with a composition very close to the original target. Because a shape-memory alloy's transition temperature range is strongly influenced by the alloy's composition, accurate composition management is critical. Using a single nitinol target allowed for the most precise control over film consistency and composition. Prior to producing the films, the target was sputtered for 3 hours under sputtering conditions of 5 mTorr argon pressure and 250 V DC power.6-9Figure 2A shows a photograph of a sputtered NiTi film on a hexagonally closepacked monolayer colloidal crystal. The film shows shining iridescent colors caused by light diffraction from the periodic nanostructures as revealed by the top- and side-view SEM images in Figures 2B-2D. TH Docket No.222112-2370 The sputtered SMA coating forms conformal layer on the ordered silica particles. The hexagonal ordering maintains at both the top and bottom surfaces of the sputtered film. The stimuli-responsive SPR properties of the nanostructured SMA films10were investigated by measuring normal-incidence specular optical reflection spectra with high- resolution Vis-NIR (HR4000, Ocean Optics) and NIR (NIR-512, Ocean Optics) spectrometers. A tungsten halogen lamp (LS-1, Ocean Optics) and a halogen lamp (DH-2000, Mikropack) were used as the light sources. When light illuminates the nanotextured surface, it reflects off the surface of the indents into the detector at a certain incident angle known as the resonance angle. The electrons in the metal film absorb the light, causing them to resonate. This resonance is also known as surface plasmon resonance (SPR), resulting in an intensity loss in the reflected spectrum, which appears as a dark band and can be seen as a dip in the SPR intensity curve. The shape and location of the SPR dip convey information about the surface nanostructure and the reflected colors. For NiTi sheets indented with 510 nm dimples and sputtered film on 1 μm silica particles, unique optical reflection spectra are observed with several SPR dips in Figure 3A and Figure 4A. It is noticed from Figure 3A that the NiTi sheet before indentation and after recovery have the same pattern and reflection, indicating a full recovery of the original martensite phase. This agrees well with the recovery of the original metallic appearance of the SMA sheet after heat treatment as shown in Figures 1A-1F. Figure 5A shows a typical X-ray diffraction (XRD) intensity curve for NiTi sheet. The sharp peak at 43 degrees 2^ angle indicates a body-centered cubic (BCC) single crystalline phase of NiTi SMA alloy. For the sputtered NiTi film shown in Figure 5B, there is a broad peak between 40 and 48 degree 2^Θ angle, indicating polycrystalline phases along with the BCC phase. Thermal annealing of the sputtered NiTi film in an inert argon environment can facilitate to convert the polycrystalline sample to the desired single crystalline SMA alloy. References [1] Benafan, O., Brown, J., Calkins, F. T., Kumar, P., Stebner, A. P., Turner, T. L., Vaidyanathan, R., Webster, J., Young, M. L (2014). Shape memory alloy actuator design: CASMART collaborative best practices and case studies, Int. J. Mech. Mater. Design, 10(1), 1- 42. [2] Askar, K., Phillips, B. M., Dou, X., Lopez, J., Smith, C., Jiang, B., & Jiang, P. (2012). Self- assembled nanoparticle antiglare coatings. Opt. Lett., 37(21), 4380-4382. TH Docket No.222112-2370 [3] Iltner, P. A., & Krieger, I. M. (1969). Diffraction of light by ordered suspensions. J. Phys. Chem., 73(7), 2386-2389. [4] Tipa, R., & Baltag, O. (2008). Study on a model of Bragg diffraction using microwaves. Rom. J. Phys, 53(1-2), 249-251. [5] Tomus, D., Tsuchiya, K., Inuzuka, M., Sasaki, M., Imai, D., Ohmori, T., & Umemoto, M. (2002). Fabrication of shape memory TiNi foils via Ti / Ni ultrafine laminates. Scripta Materialia, 47(3), 129-134. [6] Nagasaki, Y., Gholipour, B., Ou, J.-Y., Oh, S. S., Zhou, J., & Zhang, X. (2018). Optical bistability in shape-memory nanowire metamaterial array. Appl. Phys. Lett., 113(2), 021105. [7] Zhang, Y. J., Cheng, Y. T., & Grummom, D. S. (2007). Novel tribological systems using shape memory alloys and thin films. Surf. Coat. Technol., 202, 998-1002. [8] Zhang, Y., Cheng, Y. T., & Grummon, D. S. (2008). Two-way indent depth recovery in a NiTi shape memory alloy. Scripta Materialia, 58(4), 278-281. [9] Wu, M. J., Huang, W. M., Fu, Y. Q., Chollet, F., Hu, Y. Y., & Cai, M. (2009). Reversible surface morphology in shape-memory alloy thin films. J. Appl. Phys., 105, 033517.

[0010] Ritchie, R. H., Arakawa, E. T., Cowan, J. J., & Hamm, R. N. (1968). Surface plasmon resonance effect in grating diffraction. Physical Review Letters, 21(22), 1530-1533. Ratios, concentrations, amounts, and other numerical data may be expressed in a range format. It is to be understood that such a range format is used for convenience and brevity, and should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub- ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a concentration range of “about 0.1% to about 5%” should be interpreted to include not only the explicitly recited concentration of about 0.1 % to about 5 %, but also include individual concentrations (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicated range. In an embodiment, the term “about” can include traditional rounding according to significant figure of the numerical value. In addition, the phrase “about ‘x’ to ‘y’” includes “about ‘x’ to about ‘y’”. Unless defined otherwise, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described can also be used in the practice or testing of the present disclosure, the preferred methods and materials are now described. TH Docket No.222112-2370 Embodiments of the present disclosure will employ, unless otherwise indicated, techniques of separating, testing, and constructing materials, which are within the skill of the art. Such techniques are explained fully in the literature. It should be emphasized that the above-described embodiments are merely examples of possible implementations. Many variations and modifications may be made to the above- described embodiments without departing from the principles of the present disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

TH Docket No.222112-2370 CLAIMS At least the following is claimed:

1. A material, comprising: a shape memory metallic alloy structure, wherein the shape memory metallic alloy structure has a first state and a second state, wherein in the first state the shape memory metallic alloy structure has a first side having a surface grating with a periodic nanostructure or microstructure pattern, wherein in the first state the shape memory metallic alloy structure is in a first crystalline phase, wherein in the second state the shape memory metallic alloy structure has a substantially smooth or smooth surface, wherein in the second state the shape memory metallic alloy structure is in a second crystalline phase, wherein the shape memory metallic alloy structure has the characteristic of changing from the first crystalline phase of the first state to the second crystalline phase of the second state by increasing the temperature of the shape memory metallic alloy structure to a transition temperature of the shape memory metallic alloy or higher, wherein the shape memory metallic alloy structure has the characteristic of changing from the second crystalline phase of the second state to the first crystalline phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to the transition temperature of the shape memory metallic alloy or lower.

2. The material of claim 1, wherein in the first state, the shape memory metallic alloy structure is iridescent, wherein in the second state, the shape memory metallic alloy structure is not iridescent.

3. The material of claim 1, wherein the shape memory metallic alloy is selected from the group consisting of: nickel-titanium based alloy, indium-titanium based alloy, nickel- aluminum based alloy, nickel-gallium based alloy, copper based alloy, gold-cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy.TH Docket No.222112-2370 4. The material of claim 1, wherein the surface grating with periodic nanostructure or microstructure pattern is formed by indentions from nanoparticles or microparticles, wherein the nanoparticles or microparticles have a uniform diameter, wherein the diameter is about 100 nm to 100 µm.

5. The material of claim 1, wherein the surface grating with periodic nanostructure or microstructure pattern is a plurality of hemispherical three dimensional impressions in the shape memory metallic alloy, wherein a distance between pairs of the hemispherical three dimensional impressions in a group of the hemispherical three dimensional impressions is substantially the same, wherein a distance across the hemispherical three dimensional impression at the top of the hemispherical three dimensional impression is about 100 nm to 100 µm, wherein a depth of the hemispherical three dimensional impression is about 20 to 20 µm.

6. The material of claim 1, wherein the shape memory metallic alloy structure has a length of about 1 cm to 1 m, a width of about 1 cm to 1 m, or a diameter of about 1 cm to 1 m; and wherein the shape memory metallic alloy structure has a thickness of about 1 µm to 10 cm.

7. The material of claim 1, wherein the shape memory metallic alloy is selected from the group consisting of: nickel-titanium based alloy; wherein the shape memory metallic alloy structure has the characteristic of changing from the Martensite phase of the first state to the Austenite phase of the second state by increasing the temperature of the shape memory metallic alloy structure to 40° C or higher, wherein the shape memory metallic alloy structure has the characteristic of changing from the Austenite phase of the second state to the Martensite phase of the first state by decreasing the temperature of the shape memory metallic alloy structure to lower than 40° C.

8. A method of making the material of any one of claims 1 to 7, comprising: disposing a monolayer of particles on a first substrate, wherein the particles form a periodic particle pattern; disposing of a shape memory metallic alloy structure on a side of the monolayer of particles that is opposite the first structure, wherein the monolayer of particles is between the first substrate and the shape memory metallic alloy structure;TH Docket No.222112-2370 disposing a second substrate on the shape memory metallic alloy structure on the side opposite the monolayer of particles to form a sandwich structure; and applying a pressure upon the sandwich structure sufficient to form a surface grating with periodic nanostructure or microstructure pattern into the shape memory metallic alloy structure.

9. The method of claim 8, wherein the pressure is about 1 lb force to 20,000 lb force.

10. The method of claim 8, wherein the first substrate and the second substate is glass, silicon or glass / silicon substrate.

11. The method of claim 8, wherein the shape memory metallic alloy structure is made of a shape memory metallic alloy selected from is selected from the group consisting of: nickel- titanium based alloy, indium-titanium based alloy, nickel-aluminum based alloy, nickel- gallium based alloy, copper based alloy, gold-cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy.

12. The method of claim 8, wherein the surface grating with periodic nanostructure or microstructure pattern is formed by indentions from nanoparticles or microparticles, wherein the nanoparticles or microparticles have a uniform diameter, wherein the diameter is about 100 nm to 100 µm.

13. The method of claim 8, wherein the surface grating with periodic nanostructure or microstructure pattern is a plurality of hemispherical three dimensional impressions in the shape memory metallic alloy, wherein a distance between pairs of the hemispherical three dimensional impressions in a group of the hemispherical three dimensional impressions is substantially the same, wherein a distance across the hemispherical three dimensional impression at the top of the hemispherical three dimensional impression is about 100 nm to 100 µm, wherein a depth of the hemispherical three dimensional impression is about 20 to 20 µm.TH Docket No.222112-2370 14. The method of claim 8, wherein the shape memory metallic alloy structure has a length of about 1 cm to 1 m, a width of about 1 cm to 1 m, or a diameter of about 1 cm to 1 m; and wherein the shape memory metallic alloy structure has a thickness of about 1 µm to 10 cm.

15. The method of claim 8, wherein particle is selected from a silica nanoparticle, a polymer latex particle, a titania particle, a zirconia particle, an alumina particle, a gold particle, an iron oxide particle, a CdSe particle, optionally wherein the particles where the type selected has a uniform diameter, optionally wherein the diameter of the particle is about 100 nm to 100 µm.

16. A method of making the material of any one of claims 1 to 7, comprising: disposing a monolayer of particles on a first substrate, wherein the particles form a periodic particle pattern; disposing of a shape memory metallic alloy on a side of the monolayer of particles that is opposite the first structure to form a shape memory metallic alloy structure, wherein the monolayer of particles is between the first substrate and the shape memory metallic alloy structure, wherein the shape memory metallic alloy structure has a surface grating with periodic nanostructure or microstructure pattern.

17. The method of claim 16, wherein the first substrate is a glass substrate.

18. The method of claim 16, wherein the shape memory metallic alloy structure is made of a shape memory metallic alloy selected from is selected from the group consisting of: nickel- titanium based alloy, indium-titanium based alloy, nickel-aluminum based alloy, nickel- gallium based alloy, copper based alloy, gold-cadmium based alloy, iron-platinum based alloy, iron-palladium based alloy, silver-cadmium based alloy, indium-cadmium based alloy, manganese-copper based alloy, ruthenium-niobium based alloy, ruthenium-tantalum based alloy, titanium based alloy, and iron-based alloy.

19. The method of claim 16, wherein the surface grating with periodic nanostructure or microstructure pattern is formed by indentions from nanoparticles or microparticles, wherein the nanoparticles or microparticles have a uniform diameter, wherein the diameter is about 100 nm to 100 µm.TH Docket No.222112-2370 20. The method of claim 16, wherein the surface grating with periodic nanostructure or microstructure pattern is a plurality of hemispherical three dimensional impressions in the shape memory metallic alloy, wherein a distance between pairs of the hemispherical three dimensional impressions in a group of the hemispherical three dimensional impressions is substantially the same, wherein a distance across the hemispherical three dimensional impression at the top of the hemispherical three dimensional impression is about 100 nm to 100 µm, wherein a depth of the hemispherical three dimensional impression is about 20 nm to 20 µm.

21. The method of claim 16, wherein the shape memory metallic alloy structure has a length of about 1 cm to 1 m, a width of about 1 cm to 1 m, or a diameter of about 1 cm to 1 m; and wherein the shape memory metallic alloy structure has a thickness of about 1 µm to 10 cm.

22. The method of claim 16, wherein particle is selected from a silica nanoparticle, a polymer latex particle, a titania particle, a zirconia particle, an alumina particle, a gold particle, an iron oxide particle, a CdSe particle, optionally wherein the particles where the type selected has a uniform diameter, optionally wherein the diameter of the particle is about 100 nm to 100 µm.

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