Methods for producing electromagnetic radiation modifying articles, articles produced thereby, devices, and methods for modifying electromagnetic radiation - Patents.com

Abstract

The present disclosure provides methods, articles, and devices related to modifying electromagnetic radiation. The method of manufacturing the article includes a) providing a polymer matrix and optionally embedding dielectric particles in the polymer matrix to form an electromagnetic radiation modifying material, and b) obtaining initial dielectric properties of the electromagnetic radiation modifying material. The method further includes c) modeling the electromagnetic radiation modifying characteristics of the material suitable for an article obtained from the material to have a target electromagnetic radiation modifying property, thereby obtaining a simulation of the electromagnetic radiation modified article, and d) additively manufacturing the electromagnetic radiation modified article based on the simulation of the electromagnetic radiation modified article. An electromagnetic radiation modified article obtained by the method is also provided. Furthermore, an apparatus including the electromagnetic radiation modified article is provided. A method of modifying electromagnetic radiation is provided, comprising incorporating the electromagnetic radiation modified article into either an electronic device or an electromagnetic radiation generating device, or placing the article in the vicinity of the device. Aspects of the present disclosure advantageously contribute to achieving optimized materials and designs for electromagnetic radiation modified articles.

Description

[Technical field]

[0001] The present disclosure relates to modifying electromagnetic radiation emitted by a device. Summary of the Invention

[0002] Methods, articles, and devices relating to modifying electromagnetic radiation are provided. In a first aspect, a method for making an electromagnetic radiation modifying article is provided. The method includes the steps of: a) providing a polymer matrix and, optionally, embedding a plurality of dielectric particles in the polymer matrix to form an electromagnetic radiation modifying material; and b) providing an initial relative dielectric constant (ε r 1) and obtaining initial dielectric properties of the electromagnetic radiation modifying material, including an initial dielectric loss tangent (tan δ1). The method further comprises c) modeling electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material suitable for an electromagnetic radiation modified article obtained from the electromagnetic radiation modifying material to have the target electromagnetic radiation modifying property, thereby obtaining a simulation of the electromagnetic radiation modified article, and d) additively manufacturing the electromagnetic radiation modified article based on the simulation of the electromagnetic radiation modified article. Optionally, the method further comprises e) measuring the electromagnetic radiation modifying property of the electromagnetic radiation modified article obtained from additive manufacturing, and comparing the measured electromagnetic radiation modifying property of the electromagnetic radiation modified article to the target electromagnetic radiation modifying property.

[0003] In a second aspect, there is provided an electromagnetic radiation modifying article, the electromagnetic radiation modifying article being obtainable by a method according to the first aspect.

[0004] In a third aspect, there is provided an apparatus comprising an electromagnetic radiation modifying article according to the second aspect.

[0005] In a fourth aspect, there is provided a method of modifying electromagnetic radiation generated from an electromagnetic radiation generating device and received by an electronic device, the method comprising incorporating an article according to the second aspect into the electronic device, or placing an article according to the second aspect in the vicinity of the electronic device.

[0006] In a fifth aspect, there is provided a method of modifying electromagnetic radiation emitted by an electromagnetic radiation generating device, the method comprising incorporating an article according to the second aspect into, or placing in the vicinity of, an electromagnetic radiation generating device.

[0007] At least certain aspects of the present disclosure advantageously contribute to the achievement of optimized materials and designs for electromagnetic radiation modifying articles.

[0008] The above "Summary of the Invention" of this disclosure is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more specifically illustrates exemplary embodiments. In several places throughout this application, guidance is provided through the enumeration of examples, which can be used in various combinations. In each instance, the recited items serve only as a representative group and should not be construed as an exclusive enumeration. Thus, the scope of the disclosure should not be limited to the specific exemplary structures described herein, but extends to at least those structures described by the language of the claims, and equivalents of those structures. Any of the elements expressly enumerated herein as alternatives can be expressly included or excluded from the claims in any combination as desired. Various theories and possible mechanisms may be discussed herein, but in no event should such discussion be construed as limiting the subject matter that can be claimed. [Brief description of the drawings]

[0009] [Figure 1] 1 is a flow chart of an exemplary method for making an electromagnetic radiation modifying article according to the present disclosure. [Diagram 2] FIG. 1 is a schematic perspective view of an additive manufacturing apparatus. [Diagram 3] FIG. 1 is a block diagram of a general system for additive manufacturing of an article. [Figure 4]FIG. 1 is a block diagram of an overall manufacturing process for an article. [Diagram 5] 1 is a high-level flowchart of an exemplary article manufacturing process. [Figure 6] 1 is a high level flowchart of an exemplary article additive manufacturing process. [Figure 7] FIG. 1 is a schematic front view of an exemplary computing device. [Figure 8] FIG. 11 is a schematic perspective end view of a plate having an internal honeycomb structure according to Example 4. [Figure 9A] 11 is a graph showing the dielectric constant of a solid plate and a honeycomb plate according to Example 4. [Figure 9B] 1 is a graph showing the dielectric loss coefficient of a solid plate and a honeycomb plate according to Example 4. [Figure 10A] FIG. 1 is a schematic perspective view of a frequency selective surface (FSS) prototype. [Figure 10B] FIG. 10B is a schematic side view of a portion of the FSS prototype of FIG. [Figure 10C] 1 is a photograph of a sample according to Example 5. [Figure 11] FIG. 1 is a schematic cross-sectional side view of a chamber for testing an FSS. [Figure 12] 13 is a graph showing simulated and measured FSS permeability of samples according to Example 5.

[0010] The above-identified figures set forth several embodiments of the present disclosure; however, other embodiments are also contemplated as noted herein. The figures are not necessarily drawn to scale. In all cases, this disclosure presents the present invention by way of representation and not by way of limitation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Glossary As used herein, "actinic radiation" includes UV radiation, electron beam radiation, visible light, infrared radiation, gamma radiation, and any combination thereof.

[0012] As used herein, "matrix" refers to a three-dimensionally continuous medium.

[0013] As used herein, a "monomer" is a single, one-unit molecule that can be combined with itself or other monomers to form an oligomer or polymer, an "oligomer" is a moiety having 2 to 9 repeating units, and a "polymer" is a moiety having 10 or more repeating units.

[0014] As used herein, "particle" refers to a solid substance having a geometrically determinable shape. The shape may be regular or irregular. Particles can typically be analyzed, for example, with respect to particle size and particle size distribution. Particles may include one or more crystallites. Thus, particles may include one or more crystalline phases. The term "primary particle size" refers to the size of a non-associated single nanoparticle that is considered to be a primary particle. X-ray diffraction (XRD) is typically used to measure the primary particle size of crystalline materials, and transmission electron microscopy (TEM) is typically used to measure the primary particle size of amorphous materials.

[0015] As used herein, "diameter" refers to the longest linear dimension across a shape (in either two or three dimensions) that intersects the center of the shape.

[0016] As used herein, "fluid" refers to emulsions, dispersions, suspensions, solutions, and pure components having a continuous liquid phase, and excludes solid forms such as powders and particulates.

[0017] As used herein, "cure" and "polymerization" each mean the hardening or partial hardening of a composition by any mechanism, for example, heat, light, radiation, electron beam, microwave, chemical reaction, or a combination thereof.

[0018] As used herein, "cured" refers to a material or composition that has been hardened or partially hardened (eg, polymerized or crosslinked) by one or more curing mechanisms.

[0019] As used herein, "photopolymerizable" and "photohardenable" each refer to a composition that contains at least one material that can be hardened or partially hardened using actinic radiation.

[0020] As used herein, "(meth)acrylate" is shorthand for acrylate, methacrylate, or a combination thereof, "(meth)acrylic" is shorthand for acrylic, methacrylic, or a combination thereof, and "(meth)acryl" is shorthand for acrylic and methacrylic groups. "Acrylic" refers to derivatives of acrylic acid such as acrylates, methacrylates, acrylamides, and methacrylamides. "(Meth)acrylic" refers to monomers or oligomers having at least one acrylic or methacrylic group, which, if containing more than one group, are linked by an aliphatic segment. As used herein, "(meth)acrylate-functional compounds" are compounds that contain, among others, (meth)acrylate moieties.

[0021] Also, herein, all numbers are intended to be modified by the term "about", and preferably by the term "exactly". As used herein, in the context of a measured quantity, the term "about" refers to the variation of the measured quantity as would be expected by a person of ordinary skill in the art making the measurement and exercising a level of care commensurate with the purpose of the measurement and the precision of the measuring instrument used. Also, herein, the recitation of numerical ranges by endpoints includes all numbers subsumed within that range and the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0022] The term "generally," when used herein as a modifier to a characteristic or attribute, means that the characteristic or attribute would be readily recognized by one of ordinary skill in the art, unless otherwise specified, but does not require absolute precision or perfect agreement (e.g., within ±20% for quantifiable characteristics). The term "substantially," unless otherwise specified, means a high degree of approximation (e.g., within ±10% for quantifiable characteristics), but again, does not require absolute precision or perfect agreement. Terms such as identical, equal, uniform, constant, exactly, etc., are understood to not require absolute precision or perfect agreement, but rather within normal tolerances or measurement error applicable to the particular situation.

[0023] Modifying electromagnetic waves is commercially important in various ways. In many cases, an electronic device (e.g., a "victim") is protected from interfering electromagnetic waves from another device or equipment (e.g., an "interferer"), either by reflection, attenuation or redirection. With the constant increase in density of electronic devices as well as the digitalization of more and more technological fields, solutions for the protection of devices become more and more important. One field of application is the adaptation of the distribution of electromagnetic waves from antenna signals, for example to modify the direction of electromagnetic waves due to local restrictions or to increase the efficiency of antennas.

[0024] The present disclosure provides a combination of dielectric materials (e.g., dielectric polymers and / or dielectric particle-filled polymers) with specific electromagnetic radiation wave modification designs using additive manufacturing (e.g., also referred to as "3D printing") design freedom. Dielectric materials can be classified into four general material classes (i.e., transparent, redirected, absorbed, or reflected). Additive manufacturing offers unique possibilities for providing solutions for weight reduction or easier assembly due to new design options. In some cases, depending on the frequency range, specific dielectric filler particles are suitable and can be processed with polymer matrix composite-based additive manufacturing or 3D printing techniques (e.g., selective laser sintering (SLS), stereolithography (SLA), etc.). Furthermore, part design and material adaptation optimization concepts are provided herein, which enable rapid and customizable adaptation of electromagnetic wave modification designs based on application requirements. The combination of materials and design adaptation can leverage the design freedom offered by additive manufacturing, thus providing specific solutions for further improving electromagnetic wave modification capabilities for various applications.

[0025] Electromagnetic wave modification designs come in a variety of forms, including, for example, different principle lens designs, frequency selective surfaces, metamaterials, and absorbers.

[0026] Electromagnetic lenses or electromagnetic redirectors can be used to generate interference patterns, effectively focusing or redirecting electromagnetic energy to a focal point or in different directions. The required different phase delays can be realized through different runtimes (e.g., group delays) of the electromagnetic waves through the lens medium. This can be achieved by modifying either the thickness or the effective dielectric constant as a gradient along the material. The gradient can be continuous or stepped, depending on the required specifications. For example, additive manufacturing can be used to generate almost any kind of surface topology on a material to generate this gradient. The topology can also (or alternatively) be hidden inside the material block or realized by different densities of material. In the case of multi-material additive manufacturing, material gradients or compositional changes can be used.

[0027] A frequency selective surface or material acts like a filter for a given wavelength. Some frequencies are allowed to pass while others are reflected. This can be achieved by adding structural features (e.g. holes, slots, inclusions, etc.) on or within the material that have wavelengths of a certain size. By creating these kinds of resonant features, especially using additive manufacturing, substantial freedom can be achieved to create complex frequency characteristics. This can result in solutions that can be tailored to specific needs. For example, a cover for an antenna can be created that is transparent at the frequency bandwidth of the communication channel used, but reflects at other frequencies to shield the antenna from unwanted signals.

[0028] The absorber converts electromagnetic energy into heat. This phenomenon can be used, for example, to protect electronic circuits from radiation. High-loss materials can be printed via additive manufacturing with shapes designed to fit perfectly onto the printed circuit board (pcb) of the protected or interfering circuit. This design freedom allows the absorber to be used even in tight housings to support miniaturization.

[0029] Alternatively, the structure of the electromagnetic radiation modifying material can be designed to produce an effective medium. The properties of unstructured materials can be modified using hollow, porous, or lattice-like structures when the radiation wavelength is much larger than the structural feature size (e.g., more than four times larger). As an example, a direct comparison of dielectric properties can be determined for an unfilled base polymer, once as a solid plate and once using a honeycomb design to reduce the total weight, for example as described in the examples below. The effective medium principle may be used to produce materials with even lower dielectric constants (e.g., closer to 1), resulting in enhanced transparent materials. This design option also offers the potential for weight reduction.

[0030] Another variation of the effective medium principle involves metamaterials. "Metamaterial" is a general term for materials that have electromagnetic properties not normally found in nature. Usually, the real parts of the permeability and / or permittivity of the material are positive. In metamaterials, both properties are negative, resulting in a negative refractive index (i.e., double negative materials (DNG)). By designing small inclusions that are small compared to the wavelength of the surrounding medium but resonate with the bulk material, the real parts of both the permittivity and permeability can be designed to be negative for some small frequency band. Such materials can result in useful designs for, for example, antennas, lenses, miniaturization, etc.

[0031] Method for Producing Electromagnetic Radiation Modification Articles In a first aspect, a method is provided. The method comprises the steps of: a) providing a polymer matrix and optionally embedding a plurality of dielectric particles in the polymer matrix to form an electromagnetic radiation modifying material; b) Initial relative dielectric constant (ε r obtaining initial dielectric properties of the electromagnetic radiation modified material, including the initial dielectric loss tangent (tan δ1) and the initial dielectric loss tangent (tan δ1); c) modeling electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material such that an electromagnetic radiation modifying article obtained from the electromagnetic radiation modifying material has a target electromagnetic radiation modifying property, thereby obtaining a simulation of the electromagnetic radiation modifying article; d) additively manufacturing the electromagnetic radiation modifying article based on the simulation of the electromagnetic radiation modifying article; e) optionally measuring an electromagnetic radiation altering property of the electromagnetic radiation altering article resulting from the additive manufacturing and comparing the measured electromagnetic radiation altering property of the electromagnetic radiation altering article with a target electromagnetic radiation altering property.

[0032] With reference to Figure 1, a flow chart of the method of the first embodiment is provided. More specifically, the method includes a) forming 110 an electromagnetic radiation modifying material by providing a polymer matrix and optionally embedding a plurality of dielectric particles in the polymer matrix. Often, forming the electromagnetic radiation modifying material includes selecting an initial polymer matrix and selecting a plurality of initial dielectric particles for embedding therein. Exemplary polymer materials for use in the polymer matrix and the dielectric particles are described in detail below. When an unfilled polymer matrix is ​​employed, the polymer material includes a dielectric material.

[0033] The method includes: b) determining the initial relative dielectric constant (ε rThe method further includes a step 120 of obtaining initial dielectric properties of the electromagnetic radiation modifying material, including initial dielectric loss tangent (tan δ1) and initial dielectric loss tangent (tan δ1). In some embodiments, obtaining the initial dielectric properties of the electromagnetic radiation modifying material is performed by measuring the initial dielectric properties using a measurement method selected from the group consisting of a transmission and / or reflection method, a dielectric resonance method (i.e., a split post dielectric resonator (SPDR) method), a capacitance method, an LC resonance (also referred to as "U / I") method, a perturbation method, an open resonator method, and any combination thereof. A preferred method of measuring the initial dielectric properties may be selected from the group consisting of a reflection method, an LC resonance (U / I) method, a dielectric resonance (SPDR) method, and any combination thereof. Each of these methods is discussed further below. In some embodiments, the initial dielectric properties are already available, for example, accessible from a database or a data sheet.

[0034] Suitable transmission and / or reflection methods can be realized using either conductive or radiative methods. Conductive transmission and / or reflection methods include coaxial or waveguide transmission line methods. Radiative transmission and / or reflection methods include free-field measurement setups in anechoic RF measurement chambers, as well as quasi-optical methods using reflectors or lenses or combinations thereof.

[0035] A suitable dielectric resonance method (eg, split post dielectric resonator) is described in detail in the Examples below as "Dielectric Resonance (SPDR) Measurement Method."

[0036] A suitable capacitance method involves measuring well-known test capacitor structures having interchangeable dielectric media between the plates and measuring the change in capacitance conducted by the different dielectric materials.

[0037] The preferred LC resonance method (or U / I method) involves using an LCR meter to determine the resonance characteristics of the combined RLC circuit, replacing the dielectric material of the associated capacitor with the material under test, and calculating the dielectric properties from the resulting difference in the resonance characteristics.

[0038] A suitable perturbation method involves measuring the resonance characteristics of a cavity resonator, monitoring the change in the resonance characteristics when a dielectric sample is inserted, and calculating the dielectric properties from the perturbation of the resonance characteristics.

[0039] Suitable open cavity methods include, for example, the use of a Fabry-Perot open cavity.

[0040] In some embodiments, the frequency F1 at which the initial dielectric properties of the electromagnetic radiation modifying material are measured is in the range of 300 MHz to 300 GHz. In some embodiments, the frequency F1 is in the range of 300 MHz to 3 GHz (e.g., Ultra High Frequency (UHF)). In some embodiments, the frequency F1 is in the range of 3 GHz to 30 GHz (e.g., Super High Frequency (SHF)). In some embodiments, the frequency F1 is in the range of 30 GHz to 300 GHz (e.g., Extremely High Frequency (EHF)). In some embodiments, the frequency F1 is in the range of 1 to 10 GHz, 1 to 8 GHz, 1 to 6 GHz, or even 2 to 6 GHz (e.g., 5G mid-GHz band).

[0041] In some embodiments, the electromagnetic radiation modifying material has an initial dielectric constant (ε) in the range of 1 to 3.0, 1 to 2.8, 1.0 to 2.5, 1.2 to 2.3, or even 1.5 to 2.0, when measured at 5.2 GHz according to the dielectric resonance (SPDR) measurement method described in the Examples below. r In some embodiments, the electromagnetic radiation modifying material has an initial dielectric constant (ε ) in the range of 4 to 11, 4.5 to 11, 5 to 10, 5 to 9, or even 5 to 8, as measured at 5.2 GHz according to a dielectric resonance (SPDR) measurement method. r In some embodiments, the electromagnetic radiation modifying material has an initial dielectric constant (ε ) of greater than 15 when measured at 5.2 GHz according to a dielectric resonance (SPDR) measurement method. rIn some embodiments, the electromagnetic radiation modifying material has an initial dielectric constant (ε ≦100, ≦70, ≦50, ≦40, or ≦30 when measured at 5.2 GHz according to a dielectric resonance (SPDR) measurement method. r 1).

[0042] In some embodiments, the electromagnetic radiation modifying material has an initial dielectric loss tangent (tan δ1) in the range of 0.01 to 0.04, 0.01 to 0.03, or even 0.01 to 0.02 when measured at 5.2 GHz according to the dielectric resonance (SPDR) measurement method described in the Examples below. In some embodiments, the electromagnetic radiation modifying material has an initial dielectric loss tangent (tan δ1) in the range of 0.05 to 0.15, 0.06 to 0.12, or even 0.08 to 0.12 when measured at 5.2 GHz according to the dielectric resonance (SPDR) measurement method. In some embodiments, the electromagnetic radiation modifying material has an initial dielectric loss tangent (tan δ1) in the range of 0.2 to 0.5, 0.2 to 0.45, or even 0.2 to 0.4 when measured at 5.2 GHz according to the dielectric resonance (SPDR) measurement method. In some embodiments, the electromagnetic radiation modifying material has an initial dielectric loss tangent (tan δ1) of greater than 0.5 when measured at 5.2 GHz according to dielectric resonance (SPDR) measurements. In some embodiments, the electromagnetic radiation modifying material has an initial dielectric loss tangent (tan δ1) of 0.8 or less, or 0.6 or less, when measured at 5.2 GHz according to dielectric resonance (SPDR) measurements.

[0043] In some preferred embodiments, the electromagnetic radiation modifying material has an initial relative dielectric constant (ε) in the range of 12 to 15 when measured at 5.2 GHz according to the SPDR measurement method. r 1) and an initial dielectric loss tangent (tan δ1) in the range of 0.01 to 0.15. In some preferred embodiments, the electromagnetic radiation modifying material has an initial relative dielectric constant (ε r 1) and has an initial dielectric loss tangent (tan δ1) in the range of 0.2 to 0.5.

[0044] Referring again to FIG. 1 , the method for producing an electromagnetic radiation modifying article further includes step 130 of c) modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material suitable for an electromagnetic radiation modified article obtained from the electromagnetic radiation modifying material to have a target electromagnetic radiation modifying property, thereby obtaining a simulation of the electromagnetic radiation modifying article.

[0045] In some embodiments, the step of modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material is performed using initial dielectric properties of the electromagnetic radiation modifying material obtained by a method selected from the group consisting of a transmission / reflection method, a free field measurement, a transmission line method, a dielectric resonance (SPDR) method, a capacitance method, a LC resonance (U / I) method, a perturbation method, an open resonator method, and any combination thereof. Preferred measurement methods may be selected from the group consisting of a reflection / transmission method, a LC resonance (U / I) method, a dielectric resonance (SPDR) method, and any combination thereof.

[0046] Exemplary suitable electromagnetic radiation modifying features of the electromagnetic radiation modifying material may be selected from the group consisting of electromagnetic lenses, diffraction gratings, frequency selective surfaces or materials, electromagnetic energy absorbers, metamaterials, and any combination thereof. In selected embodiments, the electromagnetic radiation modifying features are electromagnetic lenses, redirectors, and / or electromagnetic energy absorbers.

[0047] In some embodiments, modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material comprises optimizing the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material to have a target electromagnetic radiation modifying property. In some embodiments, modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material comprises simulating the electromagnetic radiation modifying properties of a simulation of the electromagnetic radiation modified article by performing electromagnetic radiation modification calculations on the simulation of the electromagnetic radiation modified article. Suitable modeling techniques include, for example, but are not limited to, analytical calculations, finite element simulations, finite difference time domain simulations, and methods of moment simulations.

[0048] In some embodiments, the target electromagnetic radiation modifying property is a target relative dielectric constant (ε r In some embodiments, the target electromagnetic radiation modifying property includes a target relative permeability (μ r 2). In some embodiments, the target electromagnetic radiation modifying property comprises a magnetic property of the electromagnetic radiation modifying material that includes a target magnetic loss tangent (tan δ4) as measured at frequency F2.

[0049] In certain embodiments, the frequency F2 at which the dielectric properties of the electromagnetic radiation modifying material are measured is in the range of 300 MHz to 300 GHz. In certain embodiments, the frequency F2 is in the range of 300 MHz to 3 GHz (e.g., extremely high frequency (UHF)). In certain embodiments, the frequency F2 is in the range of 3 GHz to 30 GHz (e.g., super high frequency (SHF)). In certain embodiments, the frequency F2 is in the range of 30 GHz to 300 GHz (e.g., extremely high frequency (EHF)). In certain embodiments, the frequency F2 is in the range of 1 to 10 GHz, 1 to 8 GHz, 1 to 6 GHz, or even 2 to 6 GHz (e.g., 5G mid-GHz band).

[0050] Referring again to FIG. 1 , the method of manufacturing an electromagnetic radiation modified article further comprises d) additively manufacturing 140 the electromagnetic radiation modified article based on the simulation of the electromagnetic radiation modified article. In some embodiments, additively manufacturing the electromagnetic radiation modified article based on the simulation of the electromagnetic radiation modified article is performed using an additive manufacturing method selected from the group consisting of stereolithography (SLA), selective laser sintering (SLS), digital light processing (DLP), selective laser melting (SLM), fused deposition modeling (FDM), direct light processing, binder jetting, material jetting, and any combination thereof. In some preferred embodiments, additively manufacturing the electromagnetic radiation modified article based on the simulation of the electromagnetic radiation modified article is performed using an additive manufacturing method selected from the group consisting of stereolithography (SLA), selective laser sintering (SLS), digital light processing (DLP), material jetting, and any combination thereof. In certain embodiments, the additive manufacturing method employed comprises stereolithography (SLA). In certain embodiments, the additive manufacturing process comprises selective laser sintering (SLS). In certain embodiments, the additive manufacturing process comprises digital light processing (DLP). In certain embodiments, the additive manufacturing process comprises material jetting.

[0051] The method of printing a three-dimensional object described herein can include forming an article from multiple layers of the photopolymerizable composition described herein in a layer-by-layer manner. Furthermore, the layers of the material composition to be built can be deposited according to an image of the three-dimensional object in computer-readable form. In some or all embodiments, the photopolymerizable composition is deposited according to preselected computer aided design (CAD) parameters (e.g., a data file).

[0052] It is understood that the method of producing the three-dimensional object described herein can include so-called "stereolithography / bath polymerization" 3D printing methods. Other techniques for three-dimensional production are known and may be suitably adapted for use in the applications described herein. More generally, three-dimensional fabrication techniques are becoming available. All such techniques can be adapted for use with the photopolymerizable compositions described herein, so long as they provide fabrication viscosities and resolutions consistent with the specified article characteristics. Fabrication may be performed using any of the fabrication techniques described herein, either alone or in various combinations, using data representing the three-dimensional object, which may be reformatted or otherwise adapted to a particular printing or other fabrication technique as necessary.

[0053] It is entirely possible to form a three-dimensional object from a photopolymerizable composition using liquid bath polymerization (e.g., stereolithography). For example, in some cases, a method for printing a three-dimensional object includes holding the photopolymerizable composition described herein in a fluid state in a container and selectively applying energy to the photopolymerizable composition in the container to solidify at least a portion of the fluid layer of the photopolymerizable composition, thereby forming a hardened layer that defines a cross section of the three-dimensional object. Furthermore, the method described herein can further include raising and lowering the hardened layer of the photopolymerizable composition to provide a new or second fluid layer of unhardened photopolymerizable composition on the surface of the fluid in the container, and then selectively applying energy again to the photopolymerizable composition in the container to solidify at least a portion of the new or second fluid layer of the photopolymerizable composition, thereby forming a second solidified layer that defines a second cross section of the three-dimensional object. Furthermore, the application of energy to solidify the photopolymerizable composition can bond or adhere the first and second cross sections of the three-dimensional object to each other in the z-direction (i.e., the build direction corresponding to the direction of lifting and lowering described above). Furthermore, selectively applying energy to the photopolymerizable composition in the container can include applying actinic radiation, such as ultraviolet, visible, or electron beam radiation, having sufficient energy to cure the photopolymerizable composition. The method can also include planarizing the new layer of fluid of the photopolymerizable composition provided by raising and lowering the elevator platform. Such planarization can be performed in some cases by utilizing a wiper or roller or a recoater. Planarization involves flattening the dispensed material to remove excess material and create a uniform and smooth exposed or flat upward surface on the printer's support platform, thereby correcting the thickness of one or more layers before the material is cured.

[0054] It should be further understood that the above process can be repeated a selected number of times to provide a three-dimensional object. For example, in some cases, the process can be repeated "n" times. It is further understood that one or more steps of the method described herein, such as selectively applying energy to a layer of photopolymerizable composition, can be performed according to an image of the three-dimensional object in computer-readable form. Suitable stereolithography printers include Viper Pro SLA available from 3D Systems (Rock Hill, SC) and Asiga PICO PLUS39 available from Asiga USA (Anaheim Hills, CA).

[0055] 2 illustrates, for example, a stereolithography apparatus ("SLA") that may be used with the photopolymerizable compositions and methods described herein. In general, the apparatus 200 may include a laser 202, optics 204, steering mirrors or lenses 206, elevator 208, and platform 210 within a bath 214 filled with a photopolymerizable composition 219. In operation, the laser 202 is directed through a wall 220 (e.g., a floor) of the bath 214 to the photocurable composition, curing a cross section of the photocurable composition 219 to form an article 217, after which the elevator 208 slightly raises the platform 210 and another cross section is cured. Suitable stereolithography printers include the NextDent 5100 and Figure 4, both available from 3D Systems (Rock Hill, SC), and the Asiga PICO PLUS39, available from Asiga USA (Anaheim Hills, CA).

[0056] In some embodiments, bath polymerization by digital light processing ("DLP") employs a container of curable polymer (e.g., photopolymerizable composition). DLP-based systems project a two-dimensional cross-section onto the curable material, curing the entire desired section in a plane intersecting the projected beam at once. One suitable device for use with photopolymerizable compositions is the Rapid Shape D40 II DLP 3D printer (Rapid Shape GmbH, Heimsheim, Germany). All such curable polymer systems that may be adapted for use with the photopolymerizable compositions described herein are intended to be within the scope of "bath polymerization" or "stereolithography" as used herein. In certain embodiments, devices adapted for use in a continuous mode, such as those commercially available from Carbon 3D, Inc. (Redwood City, CA), may be employed, for example, as described in U.S. Pat. Nos. 9,205,601 and 9,360,757 (both to DeSimone et al.).

[0057] Data representing a three-dimensional article (e.g., an electromagnetic radiation-modified article) may be generated using computer modeling, such as computer aided design (CAD) data. Image data representing the design of the article can be exported to an additive manufacturing machine in STL format or any other suitable computer-processable format.

[0058] In many cases, the machine-readable medium is provided as part of a computing device. A computing device may have one or more processors, a volatile memory (RAM), a device for reading the machine-readable medium, and input / output devices, such as a display, a keyboard, and a pointing device. In addition, a computing device may also include other software, such as an operating system and other application software, firmware, or a combination thereof. A computing device may be, for example, a workstation, a laptop, a personal digital assistant (PDA), a server, a mainframe, or any other general-purpose or special-purpose computing device. A computing device may read executable software instructions from a computer-readable medium (such as a hard drive, a CD-ROM, or a computer memory), or may receive instructions from another source logically connected to the computer, such as another networked computer. Referring to FIG. 7, a computing device 700 often includes an internal processor 780, a display 710 (e.g., a monitor), and one or more input devices, such as a keyboard 740 and a mouse 720. In FIG. 7, an item 730 (e.g., a lens) is displayed on the display 710.

[0059] 3, in certain embodiments, a system 300 is employed in a method of manufacturing an electromagnetic radiation modifying article. The system 300 comprises a display 320 that displays a 3D model 310 of an article (e.g., article 730 as displayed in display 710 of FIG. 7) and one or more processors 330 that cause a 3D printer / additive manufacturing device 350 to create a physical object of the article 360 ​​in response to the 3D model 310 selected by a user. Often, an input device 340 (e.g., a keyboard and / or a mouse) is employed in conjunction with the display 320 and at least one processor 330, particularly for user selection of the 3D model 310.

[0060] 4, a processor 420 (or two or more processors) is in communication with each of a machine-readable medium 410 (e.g., a non-transitory medium), a 3D printer / additive manufacturing device 440, and optionally a display 430 for viewing by a user. The 3D printer / additive manufacturing device 440 is configured to manufacture one or more articles 450 based on instructions from the processor 420, which provides data representing a 3D model of the article 450 from the machine-readable medium 410 (e.g., article 730 as shown in display 710 of FIG. 7).

[0061] Referring to FIG. 5, for example and without limitation, an additive manufacturing method includes retrieving 510 data representing a 3D model of an article according to at least one embodiment of the present disclosure from a (e.g., non-transitory) machine-readable medium. The method further includes executing 520 an additive manufacturing application that interfaces with a modeling device using the data by one or more processors, and generating 530 a physical object of the article by a manufacturing device. One or more various optional post-processing steps 540 may be performed. Typically, uncured photocurable components are removed from the article, and in addition, the article may be further heat treated or otherwise post-cured. For example, in some embodiments, the method further includes, prior to step c), retrieving data representing a 3D model of the three-dimensional article from a non-transitory machine-readable medium, and executing 520 a 3D printing application that interfaces with a manufacturing device using the data to generate a physical object of the three-dimensional article by one or more processors.

[0062] 6, the method of manufacturing an article includes receiving 610, by a manufacturing device having one or more processors, a digital object including data defining the (e.g., three-dimensional) article, and generating 620, an article based on the digital object using the manufacturing device by an additive manufacturing process. Again, the article may be subjected to one or more steps of post-processing 630. For example, in some embodiments, the method further includes, prior to step c), receiving, by a manufacturing device having one or more processors, a digital object including data defining the three-dimensional article, and generating, by the manufacturing device by an additive manufacturing process, a three-dimensional article based on the digital object.

[0063] 1 , in some embodiments, the method of manufacturing an electromagnetic radiation modified article further includes step e) optionally measuring an electromagnetic radiation modifying property of the electromagnetic radiation modified article resulting from additive manufacturing and comparing the measured electromagnetic radiation modifying property of the electromagnetic radiation modified article to a target electromagnetic radiation modifying property 150. In some embodiments, the electromagnetic radiation modifying property is measured using a method selected from the group consisting of radiometry, conductometry, and any combination thereof.

[0064] In some embodiments, the method includes determining the initial relative permeability (μ r In some embodiments, the method further includes obtaining (e.g., measuring when the information is not otherwise available) initial magnetic properties of the electromagnetic radiation-altering material, including an initial magnetic loss tangent (tan δ3) as measured at frequency F1. Often, obtaining (e.g., measuring) the initial magnetic properties of the electromagnetic radiation-altering material is performed using a measurement method selected from the group consisting of a transmission line method, a free space transmission / reflection method, an LC resonance (U / I) method, and any combination thereof.

[0065] In some embodiments, the electromagnetic radiation-modifying material has an initial relative permeability (μ ) in the range of 1 to 1.5, 1 to 1.3, or even 1 to 1.2, when measured at 1.0 GHz according to the LC Resonance (U / I) measurement method described in the Examples below. r 1).

[0066] In some embodiments, the method further comprises replacing (e.g., iterating) the initial polymer matrix and / or the plurality of initial dielectric particles by a different polymer matrix and / or a different plurality of dielectric particles (if dielectric particles are employed) and repeating the process after modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material. In some embodiments, the method further comprises remodeling (e.g., iterating) the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material and repeating the process after measuring the electromagnetic radiation modifying properties of the electromagnetic radiation modified article obtained from additive manufacturing. Such an iterative process can contribute to efficiently developing electromagnetic radiation modified articles tailored to specific applications, especially with short optimization cycles in the design phase.

[0067] When selecting materials for simulation design optimization, not only frequency dependence but also material property aspects must be considered. Also, processability must be considered. Thus, the dielectric property needs of the material depend on a combination of the application electromagnetic radiation frequency, the needs of the design concept, the scale to print (e.g., changing the dielectric constant leading to the scaling of the design), and the scale to apply (e.g., changing the dielectric constant to fit the needs of a particular application).

[0068] In practice, a set of materials (e.g., polymer matrix and optionally dielectric particles) are selected and developed to be manufactured using 3D printing based on boundary conditions (e.g., size) compatible with the additive manufacturing process, a specific application, and the wavelength(s) to be modified. The material properties of the material(s) are then measured and applied to the design and model of the electromagnetic wave modifying article. If the model reveals a mismatch between the final design and the boundary conditions, rescaling is generally possible by adapting the material properties (e.g., by changing the dielectric constant to rescale the article).

[0069] Once the design model is complete, the part can be manufactured using additive manufacturing and the application-relevant properties (e.g., electromagnetic wave redirection) can be characterized using an open field test setup. If necessary, adaptations to the design can be made to improve the performance of the electromagnetic wave modifying article. Once an optimal design is achieved, the user can apply it.

[0070] Electromagnetic radiation modifying articles according to the present disclosure can be useful in industrial applications, such as electronic applications, telecommunications applications, and transportation market applications (e.g., automotive and aerospace applications).

[0071] The polymer matrix is ​​selected to be suitable for use in additive manufacturing. Typically, the polymer matrix is ​​selected from the group consisting of thermoplastic polymers, thermosetting polymers, elastomeric polymers, and any combination or mixture thereof. For example, the polymer matrix may be selected from the group consisting of thermoplastic polymers, thermosetting polymers, and any combination or mixture thereof. Exemplary suitable materials for use as the polymer matrix include, for example, poly(meth)acrylics, polyamides, nylons, acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), polylactic acid (PLA), poly(lactic-co-glycolic acid), polycaprolactone (PCL), polycarbonate, polystyrene, polyether ketone ketone (PEKK), polyether ether ketone (PEEK), polyphenyl sulfone (PPSF), polyaniline, polyvinyl ether (PVE), epoxides, polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polystyrene-based polymers, ... Examples of suitable polymeric materials include, but are not limited to, polyvinyl chloride, polyurethane, polyester, polyolefin, polyphenylene oxide, thermoplastic polyurethane (TPU), perfluoroalkoxy alkane (PFA), and any combination or mixture thereof.

[0072] In some embodiments, the polymer matrix is ​​selected from the group consisting of polyamides, polymeric materials based on (meth)acrylate, vinyl ether, and epoxide-containing monomers, thermoplastic polyurethanes (TPUs), perfluoroalkoxyalkanes (PFAs), and any combination or mixture thereof. In selected embodiments, the polymer matrix is ​​selected from the group consisting of polyamides (e.g., nylon 6, nylon 6,6, nylon 12, polypeptides, hexamethylene adipamide, and polycaprolactam), and polymeric materials based on (meth)acrylate-containing monomers.

[0073] Suitable monofunctional (meth)acrylate monomers include, for example, but are not limited to, dicyclopentadienyl acrylate, dicyclopentanyl acrylate, dimethyl-1-adamantyl acrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, 2-phenoxyethyl methacrylate, butyl methacrylate (e.g., tert-butyl methacrylate or isobutyl methacrylate), benzyl methacrylate, n-propyl methacrylate, 3,3,5-trimethylcyclohexyl methacrylate, butyl-cyclohexyl methacrylate (e.g., cis-4-tert-butyl-cyclohexyl methacrylate, 73 / 27 trans / ci s-4-tert-butylcyclohexyl methacrylate, or trans-4-tert-butylcyclohexyl methacrylate), 2-decahydronaphthyl methacrylate, 1-adamantyl acrylate, dicyclopentadienyl methacrylate, dicyclopentanyl methacrylate, isobornyl methacrylate (e.g., d,l-isobornyl methacrylate), dimethyl-1-adamantyl methacrylate, bornyl methacrylate (e.g., d,l-bornyl methacrylate), 3-tetracyclo[4.4.0.1.1]dodecyl methacrylate, 1-adamantyl methacrylate, isobornyl acrylate, tertiary butyl acrylate, or a combination thereof.

[0074] Exemplary monomers having two (meth)acryloyl groups include 1,2-ethanediol diacrylate, 1,3-propanediol diacrylate, 1,9-nonanediol diacrylate, 1,12-dodecanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, butylene glycol diacrylate, bisphenol A diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, polyethylene / polypropylene copolymer diacrylate, polybutadiene di(meth)acrylate, propoxylated glycerin tri(meth)acrylate, and neopentyl glycol hydroxypivalate diacrylate modified caprolactone.

[0075] Exemplary monomers having three or four (meth)acryloyl groups include trimethylolpropane triacrylate (available, for example, from Cytec Industries, Inc., Smyrna, GA, USA, under the trade name TMPTA-N, and from Sartomer, Exton, PA, USA, under the trade name SR-351), pentaerythritol triacrylate (available, for example, from Sartomer, under the trade name SR-444), ethoxylated (3) trimethylolpropane triacrylate (available, for example, from Sartomer, under the trade name SR-454), ethoxylated (4) pentaerythritol tetraacrylate (available, for example, from Sartomer, under the trade name SR-494), tris(2-hydroxyethyl isocyanurate) triacrylate (available, for example, from Sartomer, under the trade name SR-368), a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (available, for example, from Cytec Industries, Inc., Smyrna, GA, USA, under the trade name SR-351), and mixtures of pentaerythritol triacrylate and pentaerythritol tetraacrylate (available, for example, from Cytec Industries, Inc., Smyrna, GA, USA, under the trade name SR-351). Examples of suitable acrylates include, but are not limited to, those available from Eppendorf Industries, Inc. under the trade name PETIA, which has a tetraacrylate to triacrylate ratio of about 1:1, and those available under the trade name PETA-K, which has a tetraacrylate to triacrylate ratio of about 3:1), pentaerythritol tetraacrylate (available, for example, from Sartomer under the trade name SR-295), and di-trimethylolpropane tetraacrylate (available, for example, from Sartomer under the trade name SR-355).

[0076] Exemplary monomers having five or six (meth)acryloyl groups include, but are not limited to, dipentaerythritol pentaacrylate (e.g., commercially available from Sartomer under the trade name SR-399) and hexafunctional urethane acrylate (e.g., commercially available from Sartomer under the trade name CN975).

[0077] Typically, when dielectric particles are included, a plurality of dielectric particles are embedded randomly distributed in the polymer matrix. In some embodiments, the dielectric particles include inorganic materials selected from the group consisting of oxides, nitrides, carbides, borides, titanates, zirconates, silicates, and any combination or mixture thereof. Exemplary suitable dielectric particles are optionally selected from the group consisting of (e.g., hollow) glass microspheres, coated (e.g., hollow) glass microspheres (e.g., especially metal-coated hollow glass microspheres), silicon carbide, zirconium oxide, aluminum oxide, (e.g., hexagonal) boron nitride particles, barium titanate, carbon nanotubes, graphite, graphene, polytetrafluoroethylene (PTFE) particles, carbonyl iron particles, sodium bismuth titanate, lead zirconate titanate, calcium zirconate, and any combination or mixture thereof. In certain embodiments, the dielectric particles are selected from the group consisting of (e.g., hollow) glass microspheres, metal-coated (e.g., hollow) glass microspheres (e.g., especially aluminum-coated glass microspheres), silicon carbide, and any combination or mixture thereof. In selected embodiments, the dielectric particles are metal-coated hollow glass microspheres.

[0078] In certain embodiments, the (e.g., optional) dielectric particles include microparticles or nanoparticles. At least one dimension of the nanoparticles is less than 1 micrometer, e.g., 950 nanometers or less, 900, 850, 800, 750, 700, 650, 600, 550, 500, 450, 400, 350, or 300 nanometers or less; and 1 nanometer or more, 2, 5, 7, 10, 12, 15, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 125, 150, 175, 200, 225, 250, or 275 nanometers or more. In certain embodiments, the (e.g., optional) dielectric particles have an average particle size (i.e., largest dimension) of 0.5 micrometers or more, 1 micrometer or more, 2 micrometers or more, 3 micrometers or more, 4 micrometers or more, 5 micrometers or more, 6 micrometers or more, 7 micrometers or more, 8 micrometers or more, 9 micrometers or more, 10 micrometers or more, 12 micrometers or more, 15 micrometers or more, 18 micrometers or more, 20 micrometers or more, or 25 micrometers or more; and an average particle size of 100 micrometers or less, 90 micrometers or less, 80 micrometers or less, 70 micrometers or less, 60 micrometers or less, 50 micrometers or less, 40 micrometers or less, 30 micrometers or less, or 20 micrometers or less. In other words, the average particle size may be in the range of 0.5 micrometers to 100 micrometers or 0.5 micrometers to 50 micrometers.

[0079] Typically, electromagnetic radiation modified articles (and photocurable compositions for making the articles) according to the present disclosure have a volume percent (vol%) of 0.1 or more, 0.2 or more, 0.5 or more, 0.8 or more, 1.0 or more, 1.5 or more, 2.0 or more, 3.0 or more, 4.0 or more, 5.0 or more, 6.0 or more, 8.0 or more, 10.0 or more, 12.5 or more, 15.0 or more, 17.5 or more, 20.0 or more, 2 ... 5.0 vol.% or more, 27.5 vol.% or more, or 30.0 vol.% or more (e.g., optional) dielectric particles; and 70.0 vol.% or less, 65.0 vol.% or less, 62.5 vol.% or less, 60.0 vol.% or less, 57.5 vol.% or less, 55.0 vol.% or less, 52.5 vol.% or less, 50.0 vol.% or less, 47.5 vol.% or less, 45.0 vol.% or less, 42.5 vol.% or less, 40.0 vol.% or less, 37.5 vol.% or less, 35.0 vol.% or less, or 32.5 vol.% or less (e.g., optional) dielectric particles, based on the total volume of the electromagnetic radiation modifying article (or photocurable composition). Stated another way, the electromagnetic radiation modifying article (or photocurable composition) may include from 0.1 vol. % to 70 vol. %, from 1.0 vol. % to 50.0 vol. %, or from 2.0 vol. % to 25.0 vol. % (e.g., optional) dielectric particles, based on the total volume of the electromagnetic radiation modifying article.

[0080] In certain embodiments, the (e.g., optional) dielectric particles are present in an amount of 20% by weight or more, 22% by weight, 25% by weight, 28% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 41% by weight, 42% by weight, 43% by weight, or 44% by weight or more, based on the total volume of the electromagnetic radiation modifying article (or photocurable composition); or 60% by weight or less, 59% by weight, 58% by weight, 57% by weight, 56% by weight, 55% by weight, 54% by weight, 53% by weight, 52% by weight, 51% by weight, 50% by weight, 49% by weight, 48% by weight, 47% by weight, or 46% by weight or less, based on the total volume of the electromagnetic radiation modifying article. Stated another way, the electromagnetic radiation modifying article (or photocurable composition) may include 20% to 60% by weight, 25% to 60% by weight, 30% to 60% by weight, 35% to 60% by weight, 40% to 60% by weight, or 30% to 45% by weight of (e.g., optional) dielectric particles, based on the total volume of the electromagnetic radiation modifying article.

[0081] Articles and Equipment In a second aspect, the present disclosure provides a (e.g. three-dimensional) electromagnetic radiation modified article (e.g. part) obtained by a method according to the first aspect above. In particular, any detail or details of the method described above may be employed to prepare the electromagnetic radiation modified article of this second aspect.

[0082] In a third aspect, the present disclosure provides an apparatus including an electromagnetic radiation modifying article (e.g., three-dimensional) according to the second aspect. Typically, the apparatus further comprises a device selected from the group consisting of an electromagnetic radiation generating device (e.g., an interferer or transmitter) and / or an electronic device (e.g., a victim). In some embodiments, the electronic device or the electromagnetic radiation generating device is selected from the group consisting of an antenna, an Internet connected device, a smartphone, a tablet PC, a TV, a communication satellite, a wireless transmitter, a wireless router, a wireless amplifier, an autonomous driving assistance device, and any combination thereof. Typically, the electromagnetic radiation modifying article is incorporated into the apparatus or device or placed in the vicinity of the apparatus or device. The placement of the electromagnetic radiation modifying article can be selected to be between a device that emits electromagnetic radiation and a device or material that is desired to be protected from the effects of the emitted electromagnetic radiation. Thus, the electromagnetic radiation modifying article can reflect, attenuate, redirect, or any combination thereof, the emitted electromagnetic radiation to reduce the amount of electromagnetic radiation that reaches (e.g., received by) the device or material to be protected (e.g., a victim) from the emitting device.

[0083] Methods for modifying electromagnetic radiation In a fourth aspect, the present disclosure provides a method of modifying electromagnetic radiation originating from an electromagnetic radiation generating device and received by an electronic device, comprising incorporating an electromagnetic radiation modifying article according to the second aspect above into the electronic device or placing an article according to the second aspect above in the vicinity of the electronic device. In some such methods, an electromagnetic radiation modifying article according to any of the above embodiments is associated with or near the electronic device to reduce electromagnetic radiation directed to the electronic device coming from the electromagnetic radiation generating device, in which case the electronic device is the "victim." In some such methods, an electromagnetic radiation modifying article according to any of the above embodiments is associated with or near the electronic device to redirect electromagnetic radiation emitted from the electromagnetic radiation generating device to the electronic device, in which case the electronic device is the "recipient" (as opposed to the "victim"). One example of such a method is enabling reception of signals (e.g., 5G signals) in urban environments by reflecting electromagnetic radiation in a particular direction toward the electronic device.

[0084] In a fifth aspect, the present disclosure provides a method of modifying electromagnetic radiation emanating from an electromagnetic radiation generating device, the method comprising incorporating an article according to the second aspect above into the electromagnetic radiation generating device or placing an article according to the second aspect above in the vicinity of the electromagnetic radiation generating device. In some such methods, an electromagnetic radiation modifying article according to any of the above embodiments is associated with or near the electromagnetic radiation generating device to reduce electromagnetic radiation emitted from the device that may potentially interfere with other electronic devices, in which case the electronic device is a "victim." In some such methods, an electromagnetic radiation modifying article according to any of the above embodiments is associated with or near the electromagnetic radiation generating device to redirect electromagnetic radiation emitted from the electromagnetic radiation generating device to the electronic device, in which case the electronic device is a "recipient" (as opposed to a "victim").

[0085] In the above two methods, modifying often includes interfering with the electromagnetic radiation, such as by reflecting, attenuating, and / or redirecting the electromagnetic radiation. In many embodiments, the electronic device or electromagnetic radiation generating device is selected from the group consisting of an antenna, an internet connected device, a smart phone, a tablet PC, a TV, a communication satellite, a wireless transmitter, a wireless router, a wireless amplifier, an autonomous driving assistance device, and any combination thereof.

[0086] The following examples are included to illustrate further features and embodiments of the present invention. EXAMPLES

[0087] The objects and advantages of the present invention are further illustrated by the following examples, but the specific materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit the invention. These examples are merely for illustrative purposes and are not intended to limit the scope of the appended claims. Unless otherwise stated or readily apparent from the context, all parts, percentages, ratios, etc. in the examples and elsewhere in this specification are by volume.

[0088] [Table 1]

[0089] Test Method Dielectric Resonance (SPDR) Measurement Method The dielectric constant and loss tangent of the material samples were measured using a split post dielectric resonator (SPDR) in combination with a network analyzer. The nominal frequencies of the SPDR used are 10 GHz and 15 GHz. Other standard frequencies are 1.1 GHz, 2.4 GHz, and 5 GHz.

[0090] Measurement steps: -Network analyzer calibration -Adjusting the coupling between SPDR and network analyzer -Measurement of empty SPDR (resonant frequency, Q value) -Measurement of SPDR using material samples (resonant frequency, Q value) -Measurement of sample thickness -Calculation of complex dielectric parameters using SPDR dedicated software

[0091] The accuracy for a sample of thickness h is: Δε / ε=±(0.0015+Δh / h) Δtanδ=±2 * 10-5 or ±0.03 * tan δ, whichever is higher.

[0092] Material sample size for both SPDRs should be 50 mm x 40 mm x <0.5 mm.

[0093] For measurements of dielectric properties below (and including) 1 GHz, the following procedure was used: The dielectric constant and loss tangent were measured using an impedance analyzer covering the frequency range from 1 megahertz to 1 gigahertz. To measure the material properties, the analyzer was extended with a measurement fixture. The fixture for the measurement of dielectric properties converts the material parameters into a measurable impedance by using the parallel plate capacitor principle. The measurement fixture used is capable of measuring the frequency-dependent dielectric constant (Dk) and loss tangent (real and imaginary parts of the impedance) in the frequency range from 1 megahertz to 1 gigahertz.

[0094] For the most accurate results, the material under test (MUT) was prepared into a disk having a thickness of 0.3 mm to 3 mm and a diameter of ≥ 15 mm.

[0095] Calibration was performed at the material measurement site using vendor-supplied calibration artifacts.

[0096] The exact thickness of each sample disk was measured using calipers. With the known values ​​of impedance and thickness, calculations can be performed to obtain the complex value of the dielectric constant.

[0097] Example 1: Preparation, Processing, and Measurement of UV-Curable 3D Printing Materials with High Dielectric Constants Two batches of 100.0 grams UCST 45 and 150.0 grams barium titanate, respectively, were mixed in a DAC 400 FVZ / VAC-P / LR Speedmixer (Hauschild GmbH, Hamm, Germany) at 2500 rpm and 400 mbar for 4 minutes and then combined. The mixture was loaded into the reservoir of a D30II 3D printer (Rapid Shape GmbH, Heimsheim, Germany) immediately after mixing and the print job was started.

[0098] The print job was prepared using Netfabb 2019 (Autodesk, San Rafael, CA) with the following parameters: energy dose: 950 millijoules / square decimeter; support width: 200 micrometers; offset: 0 micrometers; shrinkage: 0.6 percent; Z correction: 0 micrometers; layer size: 25 micrometers; burn-in factor: 500 percent.

[0099] The 3D printed parts were carefully removed from the platform after printing and transferred to a closable container containing isopropanol. The container was transferred to a Sonorex Super RK 1028 BH ultrasonic bath (Bandelin electronic GmbH, Berlin, Germany) filled with water and exposed to ultrasonic treatment for 15 minutes. The parts were then removed from the container and the residual 3D printing material and isopropanol were removed using compressed air. This cleaning procedure was performed twice.

[0100] After each part was cleaned, the parts were post-cured in an RS Cure UV curing chamber (Rapid Shape GmbH, Heimsheim, Germany) under vacuum for 1200 seconds at maximum intensity using both wavelengths.

[0101] The dielectric properties were measured at 10 GHz and 15 GHz according to the SPDR measurement method, and the results are shown in Table 1 below.

[0102] [Table 2]

[0103] Example 2: Preparation, Processing, and Measurement of UV-Curable 3D Printing Materials with Low Dielectric Constants Two batches of 75.4 grams of SR 540, 75.4 grams of TRGDMA, 26.2 grams of MA 1, 16.6 grams of HPMA, 4.8 grams of MA 2, 1.4 grams of OMNIRAD 819, and 68 grams of iM16 K glass bubbles were mixed in a DAC 400 FVZ / VAC-P / LR Speedmixer (Hauschild GmbH, Hamm, Germany) at 1400 rpm and 400 mbar for 2 minutes. The mixture was loaded into a D30II 3D printer (Rapid Shape GmbH, Heimsheim, Germany) immediately after mixing and the print job was started.

[0104] The print job was prepared using Netfabb 2019 (Autodesk, San Rafael, CA) with the following parameters: energy dose: 500 millijoules / square decimeter; support width: 200 micrometers; offset: 0 micrometers; shrinkage: 0.6 percent; Z correction: 0 micrometers; layer size: 50 micrometers; burn-in factor: 500 percent.

[0105] The 3D printed parts were carefully removed from the platform after printing and transferred to a closable container containing isopropanol. The container was transferred to a Sonorex Super RK 1028 BH ultrasonic bath (Bandelin electronic GmbH, Berlin, Germany) filled with water and exposed to ultrasonic treatment for 15 minutes. The parts were then removed from the container and the residual 3D printing material and isopropanol were removed using compressed air. This cleaning procedure was performed twice.

[0106] After each part was cleaned, the parts were post-cured in an RS Cure UV curing chamber (Rapid Shape GmbH, Heimsheim, Germany) under vacuum for 1200 seconds at maximum intensity using both wavelengths.

[0107] The dielectric properties were measured at 2.4 GHz and 5.2 GHz according to the SPDR measurement method, and the results are shown in Table 2 below.

[0108] [Table 3]

[0109] Example 3: Preparation, processing, and measurement of thermoplastic 3D printing powder materials with high dielectric loss factor 2.15 kilograms of polyamide 12 powder and 2.85 kilograms of silicon carbide powder were weighed into a circular container and mixed first by shaking the closed container. Then, further mixing was performed for 10 minutes using a roller rack at 30 revolutions per minute. The powder container was connected to a Formiga P110 selective laser sintering 3D printer (EOS GmbH, Krailing, Germany). The printer was prepared by making a powder bed and preheating the machine at a temperature of 150°C for 2 hours under nitrogen atmosphere. For the print job, the main chamber temperature was set to 150°C and the infrared heater temperature was set to 175°C. The laser process was performed using the standard parameter set for PA12 provided by EOS.

[0110] The print job was prepared using Magics (Materialise, Lowen, Belgium).

[0111] After the printing process, the printer was allowed to cool for 12 hours, after which the parts were removed from the printer and cleaned by sandblasting with glass media.

[0112] The dielectric properties were measured at 1 GHz according to the dielectric resonance (SPDR) measurement method, and the results are shown in Table 3 below.

[0113] [Table 4]

[0114] Example 4: Use of honeycomb design to reduce the dielectric properties of 3D printed bodies Two CAD files for the plates were generated using Netfabb 2019 (Autodesk, San Rafael, CA) and Magics (Materialise, Lowen, Belgium). Both plates had a thickness of 1.85 millimeters. One plate was made as a solid body with a density of 1.15 grams per cubic centimeter. The second plate was printed using a honeycomb design resulting in a 33% density reduction. Referring to FIG. 8 , a low density plate 800 is shown having a first solid outer wall 810 connected to a second outer wall 820 by an interior material having a corrugated shape 830. Thus, the plate 800 defines a plurality of open spaces 840 that reduce the overall density of the plate 800.

[0115] The plates were printed using a 3D printing resin consisting of 75.4 grams of SR 540, 75.4 grams of TRGDMA, 26.2 grams of MA 1, 16.6 grams of HPMA, 4.8 grams of MA 2, and 1.4 grams of OMNIRAD 819. This mixture was loaded into the reservoir of a D30II 3D printer (Rapid Shape GmbH, Heimsheim, Germany) and the print job was started.

[0116] The print job was prepared using Netfabb 2019 (Autodesk, San Rafael, CA) with the following parameters: energy dose: 400 millijoules / square decimeter; support width: 200 micrometers; offset: 0 micrometers; shrinkage: 0.6 percent; Z correction: 0 micrometers; layer size: 50 micrometers; burn-in factor: 500 percent.

[0117] The 3D printed parts were carefully removed from the platform after printing and transferred to a closable container containing isopropanol. The container was transferred to a Sonorex Super RK 1028 BH ultrasonic bath (Bandelin electronic GmbH, Berlin, Germany) filled with water and exposed to ultrasonic treatment for 15 minutes. The parts were then removed from the container and the residual 3D printing material and isopropanol were removed using compressed air. This cleaning procedure was performed twice.

[0118] The dielectric properties of the solid plate and the honeycomb plate were measured according to the dielectric resonance (SPDR) measurement method. The difference in dielectric constant between the two plates is plotted as a function of frequency in the graph of Figure 9A. The difference in dielectric loss factor between the two plates is plotted as a function of frequency in the graph of Figure 9B.

[0119] Example 5: Design and verification of a purely dielectric frequency selective surface using cylindrical dielectric resonators To form a purely dielectric frequency selective surface (FSS), multiple cylindrical disk dielectric resonators were designed to be arranged in a matrix with a constant pitch. The material the samples were made from was Polyamide 12 (PA12), a dielectric material often used with 3D printers.

[0120] The electromagnetic properties of the PA12 material were measured according to a dielectric resonance (SPDR) measurement method. PA12 was determined to have a dielectric constant (e.g., real part of dielectric constant) of about 2.44 at 10 GHz and a loss tangent of 0.007.

[0121] To hold the resonators in place and increase mechanical stability, a grating structure is applied as a layer on the outer shell of the resonator array. The grating was designed such that its features (e.g., grating size) are small compared to the target wavelength, so that the entire grating has only a small effect on the resonance and can be treated as a sheet of plane material with a reduced dielectric constant. The design was performed using the 3D electromagnetic simulation software CST / Dassault Design Suite.

[0122] A model of the array prototype is shown in FIG. 10A. The prototype 1000A included a cylindrical disk dielectric resonator 1010 with a diameter that varied along the z-axis. With that resonator style, the total volume of the resonator can be adjusted very precisely without having to modify the outer diameter, and therefore in this case the outer grating structure 1020. Further dimensions can be taken from FIG. 10B. One "cell" is defined as a 24 millimeter (mm) by 24 mm square cutout in the X / Y plane, with its edges aligned tangentially to the edges of the grating 1020, and the center of the square equal to the center of the cylinder 1010.

[0123] From the 3D simulation, a 3D CAD file was generated and used to additively manufacture (3D print) a prototype sample shown in Figure 10C. Structure 1000C was analyzed using the procedures described above.

[0124] Referring to FIG. 11, to test the FSS array structure 1000C, an anechoic shielded chamber 1100 was used containing a dedicated test setup made for this measurement, and measurements were made including two well-known test antennas, including a transmitter antenna 1110 and a receiver antenna 1112 positioned facing each other on each side inside the chamber 1100. The chamber 1100 was designed to ensure that the setup was shielded from ambient effects and to minimize undesired reflections within the chamber 1100. The distance between each test antenna 1110, 1112 and the FSS sample 1000C was 2m to 2.5m and was equal for both antennas. It is preferable to choose a distance large enough to exceed the Fraunhofer distance. In the center of the chamber 1100, at the same distance from each test antenna 1110, 1112, a barrier plane 1120 made of pyramidal foam absorber was placed facing the transmitting antenna side. In the center of the plane 1120 (e.g., at a height of about 1.5 m), a small window was cut out of the absorber having the size of the FSS sample 1000C. This window was called the transmission region, and the FSS sample 1000C was placed within it. The test antennas 1110, 1112 were selected to cover the measurement bandwidth.

[0125] Calibration was performed by performing a transmission measurement with an empty transmission area, referred to as the "thru" measurement. Sample 1000C was then placed in the window area of ​​chamber 1100 and the measurement was repeated. The results were normalized to the "thru" measurement. With reference to FIG. 12, four main frequency regions were identified. One passband ranges up to about 11.4 GHz. The passband is the frequency band where RF waves can pass through the structure without being substantially attenuated (attenuation < 2 dB). The stopband ranges from about 11.4 GHz to 11.6 GHz, centered at 11.5 GHz. The stopband is defined as the frequency band where RF waves are attenuated or reflected and cannot substantially pass through the structure (attenuation ≧ 2 dB). The third region is another passband from about 11.6 GHz to about 12.5 GHz. The fourth region starts at about 12.5 GHz and is formed by higher modes of the resonator and grating. This region is not intended to be used for applications. The FSS should be designed to shift the lower frequencies in region 4 as high as possible (as far into the underlying passband as possible). Up to 12.5 GHz, the frequency behavior of the FSS can generally be described as a band-stop filter. The comparison of the measurement and simulation in Figure 12 shows good alignment with some small differences mainly due to the imperfect measurement setup that was not captured by the simulation.

[0126] The entire disclosures of patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. To the extent that any conflict or inconsistency exists between the written specification and the disclosure of any document incorporated herein by reference, the written specification shall control. Various modifications and alterations to the present disclosure will become apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. It is to be understood that the present disclosure is not intended to be unduly limited by the exemplary embodiments and examples described herein, and that such examples and embodiments are presented only as examples within the scope of the present disclosure, which is intended to be limited only by the scope of the claims set forth herein as follows.

Claims

1. 1. A method of making an electromagnetic radiation modifying article, comprising: a) providing a polymer matrix and optionally embedding a plurality of dielectric particles in said polymer matrix to form an electromagnetic radiation modifying material; b) Initial relative dielectric constant (ε ｒ obtaining initial dielectric properties of the electromagnetic radiation modifying material, including the initial dielectric loss tangent (tan δ1); c) modeling electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material such that the electromagnetic radiation modifying article obtained from the electromagnetic radiation modifying material has a target electromagnetic radiation modifying property, thereby obtaining a simulation of the electromagnetic radiation modifying article; d) additively manufacturing the electromagnetic radiation modifying article based on the simulation of the electromagnetic radiation modifying article; and e) optionally measuring the electromagnetic radiation modifying property of the electromagnetic radiation modifying article resulting from additive manufacturing and comparing the measured electromagnetic radiation modifying property of the electromagnetic radiation modifying article to the target electromagnetic radiation modifying property.

2. The method of claim 1 , wherein the plurality of dielectric particles are present and embedded randomly distributed in the polymer matrix.

3. Initial relative permeability (μ ｒ 3. The method of claim 1 or claim 2, further comprising obtaining initial magnetic properties of the electromagnetic radiation-modifying material, including initial magnetic loss tangent (tan δ), initial magnetic loss tangent (tan δ), or both.

4. 4. The method of claim 1, wherein the step of modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material comprises optimizing the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material to have a target electromagnetic radiation modifying property, simulating the electromagnetic radiation modifying properties of the simulation of the electromagnetic radiation modifying article by performing electromagnetic radiation modification calculations on the simulation of the electromagnetic radiation modifying article, or both.

5. 5. The method of claim 4, wherein the step of forming an electromagnetic radiation modifying material comprises the steps of: selecting an initial polymer matrix; and selecting a plurality of initial dielectric particles for embedding therein; and further comprising: replacing the initial polymer matrix and / or the plurality of initial dielectric particles with a different polymer matrix and / or a different plurality of dielectric particles; and repeating the process after the step of modeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material.

6. 6. The method of any one of claims 1 to 5, further comprising the steps of remodeling the electromagnetic radiation modifying characteristics of the electromagnetic radiation modifying material and repeating the process after the step of measuring the electromagnetic radiation modifying properties of the electromagnetic radiation modified article resulting from additive manufacturing.

7. The target electromagnetic radiation modifying property is a target relative dielectric constant (ε ｒ 2) and the dielectric properties of the electromagnetic radiation modifying article, including a target dielectric loss tangent (tan δ2), a target relative permeability (μ ｒ 7. The method of claim 1, wherein the magnetic properties of the electromagnetic radiation modifying material include a target magnetic loss tangent (tan δ4), or any combination thereof.

8. 8. The method according to any one of claims 1 to 7, wherein the polymer matrix is ​​selected from the group consisting of polymeric materials based on polyamides, (meth)acrylates, vinyl ethers, and epoxide-containing monomers; thermoplastic polyurethanes (TPU); perfluoroalkoxyalkanes (PFA), and any combination or mixture thereof.

9. 9. The method of any one of claims 1 to 8, wherein the dielectric particles are present and are selected from the group consisting of glass microspheres, coated glass microspheres, silicon carbide particles, zircon oxide particles, aluminum oxide particles, boron nitride particles, barium titanate particles, carbon nanotubes, graphite, graphene, polytetrafluoroethylene (PTFE) particles, carbonyl iron particles, sodium bismuth titanate particles, lead zirconate titanate particles, calcium zirconate particles, and any combination or mixture thereof.

10. 10. The method of any one of claims 1 to 9, wherein the step of obtaining an initial dielectric property of the electromagnetic radiation modifying material is performed using a measurement method selected from the group consisting of a transmission method, a reflection method, a dielectric resonance (SPDR) method, a capacitance method, a LC resonance (U / I) method, a perturbation method, an open resonator method, and any combination thereof.

11. 11. The method of any one of claims 1 to 10, wherein the electromagnetic radiation modifying feature of the electromagnetic radiation modifying material is selected from the group consisting of an electromagnetic lens, a diffraction grating, a frequency selective surface or material, an electromagnetic energy absorber, a metamaterial, and any combination thereof.

12. 12. The method of any one of claims 1 to 11, wherein the step of additively manufacturing the electromagnetic radiation modified article based on the simulation of the electromagnetic radiation modified article is performed using an additive manufacturing method selected from the group consisting of stereolithography (SLA), selective laser sintering (SLS), digital light processing (DLP), material jetting, and any combination thereof.

13. The electromagnetic radiation modifying material has an initial dielectric constant (e) in the range of 1 to 3.0, 1 to 2.8, 1.0 to 2.5, 1.2 to 2.3, 1.5 to 2.0, 4 to 11, 4.5 to 11, 5 to 10, 5 to 9, 5 to 8, or even 12 to 15, when measured at 5.2 GHz according to the dielectric resonance (SPDR) measurement method. ｒ 13. The method according to any one of claims 1 to 12, comprising:

14. 14. The method of any one of claims 1 to 13, wherein the electromagnetic radiation modifying material has an initial dielectric loss tangent (tan δ1) in the range of 0.01 to 0.04, 0.01 to 0.03, 0.01 to 0.02, 0.05 to 0.15, 0.06 to 0.12, 0.08 to 0.12, 0.2 to 0.5, 0.2 to 0.45, or even 0.2 to 0.4, when measured at 5.2 GHz according to the dielectric resonance (SPDR) measurement method.

15. The electromagnetic radiation modifying material has an initial relative permeability (μ ) in the range of 1 to 1.5, 1 to 1.3, or even 1 to 1.2, when measured at 1.0 GHz according to the LC Resonance (U / I) measurement method. ｒ 15. The method according to any one of claims 1 to 14, comprising:

16. 16. The method according to any one of the preceding claims, wherein the frequency F1 or F2 is in the range of 300 MHz to 300 GHz, 300 MHz to 3 GHz, 3 GHz to 30 GHz, or even 30 GHz to 300 GHz.

17. Electromagnetic radiation modified article obtained by the method according to any one of claims 1 to 16.

18. 20. An apparatus comprising the electromagnetic radiation modifying article of claim 17.

19. 20. The apparatus of claim 18, further comprising a device selected from the group consisting of an electromagnetic radiation generating device, an electronic device, and any combination thereof, wherein the electromagnetic radiation modifying article is incorporated into or located in proximity to the device.

20. 20. A method for modifying electromagnetic radiation generated from an electromagnetic radiation generating device and received by an electronic device, comprising incorporating an article according to claim 17 into the electronic device or placing an article according to claim 17 in the vicinity of the electronic device.

21. 20. A method of modifying electromagnetic radiation emitted by an electromagnetic radiation generating device, comprising incorporating an article according to claim 17 into the electromagnetic radiation generating device or placing an article according to claim 17 in the vicinity of the electromagnetic radiation generating device.

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