Structurally reinforced ferroelectric products, as well as methods for manufacturing and using the same.

Abstract

Various aspects of the present disclosure relate to devices, systems and methods including a ferroelectric article. The ferroelectric article can include a composite film having a first side and a second side, a first electrode electrically connected to the first side of the composite film, and a second electrode electrically connected to the second side of the composite film. The composite film can include a ferroelectric material and a polymeric reinforcement film.

Description

[Technical Field]

[0001] Cross-references to related applications This application claims the interests of Provisional Application No. 63 / 309,338, filed on 11 February 2022, which is incorporated herein by reference in its entirety for all purposes.

[0002] Field of Invention This disclosure generally relates to ferroelectric materials reinforced with structural components, thereby creating products exhibiting superior ferroelectric properties and improved structural properties. [Background technology]

[0003] Background of the Invention Ferroelectricity is a property of certain materials that possess spontaneous electric polarization that can be reversed by the application of an external electric field. Ferroelectric materials also exhibit piezoelectric properties. A variety of ferroelectric materials exist, including ferroelectric ceramics and ferroelectric polymers. Some of these ferroelectric materials also exhibit relaxor ferroelectric properties. Examples of ferroelectric polymers, though not limited to them, include vinylidene fluoride (VDF) copolymers (e.g., poly(vinylidene fluoride-trifluoroethylene) (p(VDF-TrFE))) and VDF terpolymers (e.g., poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (p(VDF-TrFE-CFE) and poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (p(VDF-TrFE-CTFE))).

[0004] Applications of ferroelectric materials include, but are not limited to, sensors, energy storage, non-volatile memory storage, transducers, actuators, and electrothermal heating / cooling. However, many of these ferroelectric materials lack sufficient strength or formability for use in specific applications. Therefore, reinforcing materials are often included when manufacturing ferroelectric articles. Many reinforcing materials can negatively affect electrical performance (compared to unsupported ferroelectric materials) and / or suffer from a lack of strength, inadequate rigidity / flexibility, or may not be sufficiently inert to the environmental conditions of the target application (chemical stability, thermal stability, etc.). Finally, many reinforcing materials may not sturdily bond the ferroelectric material and / or electrodes, or may need to be removable.

[0005] The problem to be solved is to provide ferroelectric articles containing reinforced ferroelectric materials that, through the presence of reinforcing materials, enable the formation of thinner, stronger articles with desired mechanical properties and electroactivity suitable for various applications. [Overview of the project]

[0006] Summary of the Invention The above problems were solved by providing a ferroelectric article that includes electrodes electrically coupled to a composite film in which a ferroelectric material is durablely bonded to a polymer-reinforced film. Mechanical reinforcement enables the formation of thin, strong, and durable films with electroactivity suitable for various product applications. Thinner films allow for higher polarization when stimulated with lower drive voltages, improving film handling and increasing the ability to include additional processing steps (e.g., electrode deposition, multilayer and composite formation with additional materials such as VDF terpolymer / relaxer ferroelectrics), simplifying the manufacture of end-use articles / devices. The ferroelectric article can include multiple durable composite films arranged in various configurations (stacks, spirals, etc.).

[0007] According to one example ("Example 1"), the ferroelectric article includes a composite film having a first surface and a second surface, where the composite film includes a ferroelectric material and a polymer reinforcing film, a first electrode electrically connected to the first surface of the composite film, and a second electrode electrically connected to the second surface of the composite film.

[0008] According to another example ("Example 2"), in addition to Example 1, the polymer reinforcing film includes a densified and / or shrunk film including macrostructural folding portions and / or microfolding fibrils.

[0009] According to another example ("Example 3"), in addition to Example 1, the ferroelectric material includes a ferroelectric polymer, a ferroelectric ceramic, or a combination thereof.

[0010] According to another example ("Example 4"), in addition to the foregoing examples, the ferroelectric polymer includes a vinylidene difluoride (VDF) copolymer or terpolymer.

[0011] According to another example ("Example 5"), in addition to the foregoing examples, the ferroelectric polymer includes one or more of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)), poly(vinylidene fluoride-trifluoroethylene) (VDF-TrFE), or a combination thereof.

[0012] According to another example ("Example 6"), in addition to the foregoing examples, the ferroelectric ceramic includes one or more of barium strontium titanate (BST), barium zirconium titanate (BZT), PZT (lead, zirconium, titanium, oxygen), PbTiO3 (PT), Pb(Mg ,

[0013] , 1 / 3 , 2 / 3 Nb 2 / 3 )O3 (PMN), Pb(Mg 1 / 3 Nb 2 / 3 )O3-PbTiO3 (PMN-PT), LiTaO3, or a combination thereof.

[0013] According to another example ("Example 7"), in addition to the examples described above, the ferroelectric ceramic comprises one or more of the following: nanoparticles, nanowires, nanorods, nanocubes, nanofillers, or combinations thereof.

[0014] In another example ("Example 8"), in addition to the examples described above, the ferroelectric material includes a ferroelectric polymer and a ferroelectric ceramic particle filler.

[0015] In another example ("Example 9"), in addition to the above examples, the polymer-reinforced film includes a microporous film having pores, the microporous film including a polyolefin, a fluorinated polyolefin, or a combination thereof.

[0016] According to another example ("Example 10"), in addition to the examples described above, the polymer-reinforced film comprises one or more of the following: ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), polyparaxylylene (PPX), vinylidene fluoride (VDF) copolymer (VDF-co-TFE or TrFE), ethylenetetrafluoroethylene (ETFE), poly(tetramethyl-p-sylphenylenesiloxane) (PTMPS), or a combination thereof.

[0017] In another example ("Example 11"), in addition to the examples described above, the polymer-reinforced film includes an expandable polymer having a microstructure of interconnected nodes and void volumes defining a plurality of pores, an expandable polymer having a microstructure of substantially only fibrils and void volumes defining a plurality of pores, or a combination thereof.

[0018] According to another example ("Example 12"), in addition to Example 11, the expanded polymer includes one or more of the following: expanded polytetrafluoroethylene (ePTFE), expanded ultra-high molecular weight polyethylene (ePE), expanded polyparaxylylene (ePPX), expanded VDF-co-TFE copolymer, expanded VDF-co-TrFE copolymer, expanded ethylenetetrafluoroethylene (eETFE), expanded poly(tetramethyl-p-sylphenylenesiloxane (ePTMPS)), or combinations thereof.

[0019] In another example ("Example 13"), in addition to Example 11 or 12, the microstructure of the nodes, fibrils, or combinations thereof of the expanded polymer is partially or completely coated with a conductive metal coating to define the coated microstructure, and furthermore, the coated microstructure retains at least a portion of the void volume after coating.

[0020] In another example ("Example 14"), in addition to the above example, the ferroelectric material forms a coating on the reinforcing film.

[0021] In another example ("Example 15"), in addition to Example 11 or 12, the ferroelectric material is partially or completely absorbed within the void volume of the reinforcing film.

[0022] In another example ("Example 16"), in addition to the examples described above, the ferroelectric polymer comprises one or more of the following: poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)), poly(vinylidene fluoride-trifluoroethylene) (VDF-TrFE), or a combination thereof, and furthermore, the ferroelectric polymer is partially or completely absorbed within a reinforcing film of stretched ePTFE.

[0023] According to another example ("Example 17"), in addition to the above example, the composite film has a thickness of 1 μm or more and 20 μm or less.

[0024] According to another example ("Example 18"), in addition to Example 17, the composite film has a thickness of 1 μm or more and 10 μm or less.

[0025] In another example ("Example 19"), in addition to the above example, the polymer-reinforced film has a mass of 5 g / m² per unit area. 2 The following applies:

[0026] In another example ("Example 20"), in addition to Example 19, the polymer-reinforced film has a mass of 4 g / m² per unit area. 2 The following applies:

[0027] In another example ("Example 21"), in addition to Example 19, the polymer-reinforced film has a mass of 3 g / m² per unit area. 2 The following applies:

[0028] According to another example ("Example 22"), in addition to the above example, the composite film has a certain total mass, and further comprises a reinforcing film of 20 wt% or less based on the total mass of the composite film, and a ferroelectric material of 80 wt% or more based on the total mass of the composite film.

[0029] According to another example ("Example 23"), in addition to the above example, the composite film has a certain total mass, and further comprises a reinforcing film of 15 wt% or less based on the total mass of the composite film, and a ferroelectric material of 85 wt% or more based on the total mass of the composite film.

[0030] According to another example ("Example 24"), in addition to the above example, the composite film has a certain total mass, and further comprises a reinforcing film of 10 wt% or less based on the total mass of the composite film, and a ferroelectric material of 90 wt% or more based on the total mass of the composite film.

[0031] In another example ("Example 25"), in addition to the above example, the reinforcing film is biaxially oriented, has a mechanical direction (MD) matrix tensile strength of at least 30 MPa, and a transverse direction (TD) matrix tensile strength of at least 30 MPa.

[0032] In another example ("Example 26"), in addition to Example 19, the ratio of the MD matrix tensile strength to the TD matrix tensile strength is 1.0:0.1 to 0.1:1.0.

[0033] In another example ("Example 27"), in addition to Examples 19-21, the reinforcing film has a porosity of at least 30%, as measured before the addition of the ferroelectric material.

[0034] In another example ("Example 28"), in addition to the examples described above, the upper and / or lower electrodes include: a) a layer of conductive metal alumina with a thickness of 80 nm or less; b) a layer of conductive thermoplastic resin poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS); c) a layer of conductive ink containing silver nanoparticles or silver nanowire ink deposited by digital printing, spraying, or screen printing; or any combination of a, b, or c.

[0035] In another example ("Example 29"), in addition to the examples described above, the ferroelectric composite includes multiple composite films in a stacked configuration.

[0036] In another example ("Example 30"), in addition to the examples described above, the multiple composite films include a laminated structure.

[0037] According to another example ("Example 31"), in addition to Example 28 or 30, at least one of the composite films in the stack configuration is different from at least one of the other composite films in the material.

[0038] According to another example ("Example 32"), in addition to Examples 28-31, at least one of the composite films in the stack configuration has a different thickness from at least one of the other films in the material.

[0039] According to another example ("Example 33"), in addition to Examples 28-32, at least one of the composite films in the stack configuration has a different strength from at least one of the other films in the material.

[0040] According to another example ("Example 34"), in addition to Examples 27-31, at least one of the composite films in the stack configuration has a different orientation from at least one of the other films in the material.

[0041] In another example ("Example 35"), the device includes a ferroelectric article from any of the examples described above.

[0042] Another example ("Example 36") describes a method for manufacturing a ferroelectric article, the method comprising: providing a polymer-reinforced film having a first surface and a second surface, wherein the polymer-reinforced film has a microstructure of interconnected nodes by fibrils or a microstructure of substantially only fibrils, the microstructure further defining void volumes defining a plurality of pores; applying a ferroelectric material to the polymer-reinforced film to form a reinforced ferroelectric composite; and applying at least one first electrode to the first surface and at least one second electrode to the second surface of the reinforced ferroelectric composite to form a ferroelectric article.

[0043] The examples described herein are merely illustrative and should not be construed as limiting or narrowing any of the inventive concepts provided otherwise in this disclosure. Although several examples are disclosed, further embodiments will become apparent to those skilled in the art from the following detailed description, which illustrates illustrative examples. Therefore, the drawings and detailed description should be considered as illustrative and not restrictive in nature. [Brief explanation of the drawing]

[0044] Brief explanation of the drawing The accompanying drawings are included to provide a further understanding of this disclosure, are incorporated herein and constitute part thereof, illustrate embodiments, and help to illustrate the principles of this disclosure together with the description.

[0045] [Figure 1] Figure 1 is a cross-sectional scanning electron microscope (SEM) image of the monolithic film of Example 1.

[0046] [Figure 2] Figure 2 is a graph illustrating the differential scanning calorimetry (DSC) results of the samples prepared in Example 1 and Example 2.

[0047] [Figure 3] Figure 3 is a graph illustrating the results of tensile tests in the mechanical (downweb) direction for the monolithic films prepared in Example 1 and Example 2.

[0048] [Figure 4] Figure 4 is a graph illustrating the results of the transverse tensile tests on the monolithic films prepared in Example 1 and Example 2.

[0049] [Figure 5] Figure 5 shows a cross-sectional SEM image of the annealed monolithic film from Example 2.

[0050] [Figure 6] Figure 6 is a graph illustrating the voltage breakdown test shown in the wave plot of the annealed monolithic film of Example 2.

[0051] [Figure 7] Figure 7 is a graph illustrating the polarization data of the monolithic film in Example 2.

[0052] [Figure 8] Figure 8 shows a cross-sectional SEM image of the composite film prepared in Example 3.

[0053] [Figure 9]Figure 9 shows a cross-sectional SEM image of the composite film prepared in Example 4.

[0054] [Figure 10] Figure 10 is a graph illustrating the polarization data of the composite film in Example 4.

[0055] [Figure 11] Figure 11 shows a cross-sectional SEM image of the composite film prepared in Example 5.

[0056] [Figure 12] Figure 12 is a graph illustrating the polarization data of the composite film in Example 6.

[0057] [Figure 13] Figure 13 shows a cross-sectional SEM image of the composite film prepared in Example 7.

[0058] [Figure 14] Figure 14 is a graph illustrating the polarization data of the composite film in Example 7.

[0059] [Figure 15] Figure 15 is a graph illustrating the polarization data of the composite film in Example 8.

[0060] [Figure 16] Figure 16 is a graph illustrating the polarization data of the composite film in Example 9.

[0061] [Figure 17] Figure 17 is a graph illustrating the polarization data of the composite film in Example 10.

[0062] [Figure 18] Figure 18 is a graph illustrating the polarization data of the composite film in Example 11.

[0063] [Figure 19] Figure 19 shows a cross-sectional SEM image of the composite film prepared in Example 12.

[0064] [Figure 20] Figure 20 is a graphical representation of the tensile test results in the mechanical direction (MD) and transverse direction (TD) for two different reinforced terpolymer-based composite films prepared in Examples 12 and 14.

[0065] [Figure 21] Figure 21 is a graph illustrating the polarization data of the composite film in Example 12.

[0066] [Figure 22] Figure 22 is a graph illustrating the polarization data of the composite film in Example 13.

[0067] [Figure 23] Figure 23 is a graph illustrating the results of the dynamic tensile test in the transverse direction (TD) of the composite film prepared in Example 14.

[0068] [Figure 24] Figure 24 is a graph illustrating the polarization data of the composite film in Example 14.

[0069] [Figure 25] Figure 25 shows a cross-sectional SEM image of the composite film prepared in Example 15.

[0070] [Figure 26] Figure 26 is a graph illustrating the polarization data of the composite film in Example 15.

[0071] [Figure 27] Figure 27 is a graph illustrating the polarization data of the composite film in Example 16.

[0072] [Figure 28] Figure 28 shows a cross-sectional SEM image of the composite film prepared in Example 18.

[0073] [Figure 29]Figure 29 is a graph illustrating the polarization data of the composite film in Example 18. [Modes for carrying out the invention]

[0074] Detailed description of the invention Those skilled in the art will readily understand that various aspects of this disclosure can be realized by any number of methods and apparatus configured to perform the intended functions. Furthermore, it should be noted that the accompanying figures referenced herein are not necessarily drawn to scale and may be exaggerated to illustrate various aspects of this disclosure; in this respect, the figures should not be interpreted as limiting.

[0075] definition As used herein, “electroactive polymer” or “EAP” refers to a polymer that exhibits a change in size or shape when stimulated by an electric field.

[0076] As used herein, “piezoelectric” refers to a material capable of accumulating electric charge in response to applied mechanical stress. This is a reversible process, and the reversible piezoelectric effect generates internal mechanical strain caused by the applied electric field.

[0077] As used herein, “ferroelectric material” refers to a material capable of spontaneous electric polarization that can be reversed or switched by an external electric field. Examples include ferroelectric ceramics, ferroelectric polymers, and combinations thereof. Typically, ferroelectricity is observed only below a specific phase transition temperature called the Curie temperature (TC), above which it becomes paraelectric, the spontaneous polarization disappears, and the ferroelectric material is converted to a paraelectric state.

[0078] As used herein, “ferroelectric polymer” refers to a group of crystalline polar polymers that are also ferroelectric, meaning that they maintain a permanent electric polarization that can be reversed or switched by an external electric field.

[0079] As used herein, "relaxer ferroelectric" refers to a group of ferroelectric materials that exhibit high electrical strain. When an electric field is applied to them, their shape changes, i.e., their surface area increases and their thickness decreases.

[0080] As used herein, “relaxer ferroelectric polymer” refers to a polymer that exhibits both a high dielectric constant and low residual polarization, and therefore achieves significantly higher energy density and greater charge-discharge efficiency than conventional ferroelectrics in capacitive energy storage applications.

[0081] As used herein, “ferroelectric article” means a composite film comprising a polymer-reinforced film (non-removable) + a ferroelectric material, wherein the composite film has a first surface and a second surface, with at least one electrode electrically connected to the first surface and at least one electrode connected to the second surface.

[0082] As used herein, “electrocaloric effect” refers to the phenomenon in which a bipolar component, i.e., a material having a specific dielectric property, exhibits a reversible temperature change under an applied electric field under adiabatic conditions.

[0083] As used herein, the terms “densification,” “shrinkage,” or “structuring” are used interchangeably to refer to polymer-reinforced films that have been densified in one or more transverse or mechanical directions before the application of a ferroelectric material. It should be understood that densification is not limited to one direction. It can be performed sequentially or simultaneously in transverse, mechanical, or both directions. In one exemplary embodiment, a polymer-reinforced film is densified transversely before the application of a ferroelectric polymer material. The densified polymer-reinforced film forms macrostructural folds and / or microfolded fibrils within the film, giving the polymer-reinforced film a low modulus and flexibility. The densified polymer-reinforced film may also exhibit out-of-plane features such as wrinkles or folds in the film, such as, for example, but not limited to, the methods described in Zaggl et al. EP3061598A1 and Zaggl et al. U.S. Patent No. 9,849,629. It should be noted that polymer-reinforced films can be non-mechanically "densified" by alternative methods such as thermal shrinkage, solvent shrinkage, or other suitable methods.

[0084] Polymer-reinforced film Polymer-reinforced films are microporous films that can be prepared from a variety of polymers. In one embodiment, the polymer-reinforced film includes a fibrillated microstructure. In a preferred embodiment, the fibrillated microstructure includes nodes interconnected by fibrils (see Gore Patent No. 3,953,566 for examples of node and fibril microstructures).

[0085] Polymer-reinforced films are prepared from fibrillable polymers. Specific examples of fibrillable polymers (e.g., those that can be processed into films having a node-fibril microstructure) include, but are not limited to, ultra-high molecular weight polyethylene (UHMWPE) (Sbriglia, U.S. Patent No. 10,577,468), polylactic acid (PLLA, Sbriglia, U.S. Patent No. 9,732,184), and copolymers of vinylidene fluoride with tetrafluoroethylene or trifluoroethylene (e.g., VDF-co-(TFE or TrFE)poly Examples include (Mar, U.S. Patent No. 10,266,670 of Sbriglia), poly(ethylenetetrafluoroethylene) (ETFE, U.S. Patent No. 9,932,429 of Sbriglia), polyparaxylylene (PPX, U.S. Patent Publication No. 2016-0032069 of Sbriglia), polytetrafluoroethylene (PTFE, U.S. Patent No. 3,315,020 of Gore, U.S. Patent No. 3,953,566 of Gore, and U.S. Patent No. 7,083,225 of Baille), and (tetramethyl-p-sylphenylenesiloxane) (PTMPS) (see International Patent Publication No. WO2021 / 202628 A1).

[0086] In at least one embodiment, the polymer-reinforced film is a porous fluoropolymer film. In at least one exemplary embodiment, the polymer-reinforced film is a polytetrafluoroethylene (PTFE) film or an ePTFE film. In a preferred embodiment, the polymer-reinforced film is an ePTFE film. EPTFE films prepared according to the methods described in U.S. Patent No. 7,306,729 by Bacino et al., U.S. Patent No. 3,953,566 by Gore, U.S. Patent No. 5,476,589 by Bacino, or U.S. Patent No. 5,183,545 by Branca et al. may be used herein. In one preferred embodiment, the polymer-reinforced film is an ePTFE film as described in U.S. Patent No. 7,306,729.

[0087] Throughout this application, for convenience, the term "PTFE" is used herein, and it is intended to include not only polytetrafluoroethylene, but also stretched PTFE, stretched modified PTFE, and copolymers of stretched PTFE as described in Branca U.S. Patent No. 5,708,044, Baillie U.S. Patent No. 6,541,589, Sabol et al. U.S. Patent No. 7,531,611, Ford U.S. Patent No. 8,637,144, and Xu et al. U.S. Patent No. 9,139,669.

[0088] The porous fluoropolymer membrane can also include a polymer material comprising a functional tetrafluoroethylene (TFE) copolymer material, where the functional TFE copolymer material includes a functional copolymer of TFE and PSVE (perfluorosulfonyl vinyl ether), or TFE and other suitable functional monomers (e.g., but not limited to, vinylidene fluoride (VDF), vinyl acetate, or vinyl alcohol). The functional TFE copolymer material can be prepared, for example, according to the methods described in Xu et al. U.S. Patent No. 9,139,707 or Xu et al. U.S. Patent No. 8,658,707.

[0089] In one embodiment, the polymer reinforcing membrane has a basis weight of 5 g / m 2 or less, 4 g / m 2 or less, 3 g / m 2 or less, 2 g / m 2 or less, or 1 g / m 2 or less. In another embodiment, the polymer reinforcing membrane has a basis weight range of 5 g / m 2 to 0.01 g / m 2 , 4 g / m 2 to 0.1 g / m 2 , 3 g / m 2 to 0.1 g / m 2 , 2 g / m 2 to 0.1 g / m 2 , 4 g / m 2 to 0.2 g / m 2 or 3 g / m 2 to 0.2 g / m 2 .

[0090] In another embodiment, the polymer-reinforced film has a thickness of 1 cm or less, 0.5 cm or less, 0.1 cm or less, or 0.01 cm or less. In yet another embodiment, the polymer-reinforced film has a thickness of at least 0.05 μm, at least 0.1 μm, or at least 0.2 μm. In another embodiment, the polymer-reinforced film has a thickness range of 0.5 cm to 0.05 μm, 5 mm to 0.05 μm, 1 mm to 0.05 μm, 500 μm to 0.05 μm, 100 μm to 0.05 μm, 50 μm to 0.05 μm, 40 μm to 0.05 μm, 30 μm to 0.05 μm, 20 μm to 0.05 μm, 15 μm to 0.05 μm, 40 μm to 0.1 μm, 30 μm to 0.1 μm, 20 μm to 0.1 μm, 15 μm to 0.1 μm, 10 μm to 0.1 μm, 40 μm to 0.2 μm, 30 μm to 0.2 μm, 20 μm to 0.2 μm, or 10 μm to 0.2 μm.

[0091] The polymer-reinforced film (before coating or absorption) has a porosity of at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, or at least 80%. In one embodiment, the polymer-reinforced film has a porosity range of 50% to 98%, 50% to 95%, 50% to 90%, or 50% to 85%.

[0092] The polymer-reinforced film has a matrix tensile strength (MTS) of at least about 30 MPa, at least about 50 MPa, at least about 100 MPa, at least about 150 MPa, at least about 200 MPa, or at least 300 MPa in both the mechanical direction (MD) and the transverse direction (TD) (direction perpendicular to MD). With respect to matrix tensile strength, the polymer-reinforced film can be unbalanced (strength in one direction is significantly different from strength in the orthogonal direction) or balanced (strengths in MD and TD are similar). In another embodiment, the polymer-reinforced film has a matrix tensile strength ratio determined as MD:TD of about 0.1:1.0 to 1.0:0.1, or about 0.5:1.0 to 1.0:0.5, or about 0.7:1.0 to 1.0:0.7.

[0093] In a preferred embodiment, the polymer-reinforced film is a structured (also referred to herein as “densified”) film. Simply put, a densified polymer-reinforced film forms macro-structured folds and / or micro-folded fibrils within the film, giving the polymer-reinforced film a low modulus and flexibility. A densified polymer-reinforced film may also exhibit out-of-plane features such as wrinkles or folds ("buckles") within the film, including, but not limited to, the methods described in Zaggl et al. EP3061598 A1 and Zaggl et al. U.S. Patent No. 9,849,629. Alternatively, it should be noted that polymer-reinforced films can also be “densified” non-mechanically using thermal shrinkage, solvent shrinkage, or other suitable methods.

[0094] The "buckles" or out-of-plane structures in the film may have a height of at least twice the thickness of the non-densified film. Furthermore, the height of the out-of-plane (i.e., Z-direction) structures may range from about 2 μm to about 2000 μm or from about 20 μm to about 1000 μm. In addition, the structural density in at least one direction is at least 1 buckle per mm, at least 2 buckles per mm, at least 3 buckles per mm, at least 4 buckles per mm, at least 5 buckles per mm, at least 6 buckles per mm, at least 7 buckles per mm, at least 8 buckles per mm, at least 9 buckles per mm, or at least 10 buckles per mm. In some embodiments, the structural density is 1 to 10 buckles per mm, 1 to 7 buckles per mm, 1 to 5 buckles per mm, or 1 to 3 buckles per mm.

[0095] In an alternative embodiment taught in Zaggl et al. WO2016 / 135188, a porous membrane having a nodal and fibril structure can be compressed so that virtually no structure is introduced in the "z" direction (i.e., fibril densification within the nodal and fibril structure).

[0096] Ferroelectric materials Polymer-reinforced films can be used to form composite films that support various ferroelectric materials, such as ferroelectric polymers, ferroelectric ceramics, and combinations thereof. In one embodiment, examples of ferroelectric polymers include ferroelectric copolymers (such as poly(vinylidene fluoride-trifluoroethylene) (VDF-TrFE)) and ferroelectric terpolymers (poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)) and combinations thereof. In one embodiment, the ferroelectric polymer is poly(vinylidene fluoride-co-trifluoroethylene) (e.g., SOLVENE® 250 / P300, Solvay SA Corp., Brussels, Belgium, about 75 mol% VDF and 25 mol% TFE), poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer p(VDF-TrFE-CTFE) (e.g., SOLVENE®) T; approximately 63 mol% VDF, 28 mol% TrFE, and 9 mol% CTFE) and combinations thereof.

[0097] Examples of coating methods that are not limited to these include rapid thermal evaporation, vapor deposition, spray coating, slot die coating, knife-over-roll coating, Meyer bar coating, gravure printing, screen printing, and roller coating. The ferroelectric material can have a thickness of approximately 1 nm to 20 μm, approximately 1 nm to 15 μm, approximately 1 nm to 10 μm, or approximately 1 nm to 5 μm.

[0098] The ferroelectric material is partially or completely distributed across any surface of the polymer-reinforced film. In one embodiment, the ferroelectric material is partially or completely distributed across any surface of the densified / structured polymer-reinforced film. Furthermore, the ferroelectric material may be applied to form a pattern (e.g., circles, squares, lines, or grids) on the surface of the polymer-reinforced film. In some embodiments, the ferroelectric material forms a monolithic (e.g., continuous) coating on the surface. In another embodiment, the ferroelectric material penetrates at least partially into the thickness of the polymer-reinforced film. The depth of penetration can be substantially the same throughout the polymer-reinforced film. However, in some embodiments, the depth of partial penetration varies in porous polymer-reinforced films. The porosity of the polymer-reinforced film facilitates the penetration of the ferroelectric material into the film. In a preferred embodiment, the ferroelectric material is a poly(vinylidene fluoride-co-trifluoroethylene) copolymer, a poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) terpolymer, or a combination thereof, and the polymer-reinforced film is a stretched PTFE film having a microstructure mainly formed from fibrils or nodes interconnected by fibrils.

[0099] Polymer-reinforced films can be used to support granular ferroelectric materials such as ferroelectric ceramics. Examples of ferroelectric ceramics include barium strontium titanate (BST), barium zirconium titanate (BZT), PZT (lead, zirconium, titanium, oxygen), PbTiO3 (PT), and Pb(Mg). 1 / 3 Nb 2 / 3 )O3(PMN), Pb(Mg 1 / 3 Nb 2 / 3Examples include O3-PbTiO3(PMN-PT), LiTaO3, or combinations thereof. Ferroelectric ceramics can be provided in various particle form factors such as nanoparticles, nanowires, nanorods, nanocubes, nanofillers, or combinations thereof. Ferroelectric particles can be added as fillers when forming fibrillated polymer-reinforced films, applied as coatings, or in combination thereof. Ferroelectric materials can be applied to polymer-reinforced films by known deposition and coating methods.

[0100] Polymer-reinforced films can be used to form composite materials comprising one or more ferroelectric polymers and one or more ferroelectric ceramic particles. In one embodiment, the ferroelectric polymers and ferroelectric ceramics may be combined separately with the polymer-reinforced film, or they may be combined and applied simultaneously to the polymer-reinforced film. In another embodiment, the ferroelectric ceramic particles are present as fillers within a fibrillated (preferably stretched PTFE) polymer-reinforced film, after which the ferroelectric polymer and / or a mixture of the ferroelectric polymer / ferroelectric ceramic particles are applied (coated / absorbed).

[0101] electrodes for ferroelectric articles Electroactive devices (i.e., sensors, actuators, etc.) are typically stimulated by the application of an electric field. The ferroelectric article of the present invention comprises a composite film of a ferroelectric material on a polymer support and at least two electrodes for providing an electric field. Electrically, the ferroelectric article of the present invention typically has a thickness "d" in the range of 2 to 25 μm and a relative permittivity εr of 10 to 55 F·m -1 It functions as a capacitive device comprising an insulating dielectric polymer film within a certain range. The film itself is considered to be a thin, highly polar VDF-based copolymer and / or terpolymer composite film reinforced with a thin non-polar film (e.g., ePTFE). Two electrodes having an area "A" are applied to the composite film to provide an electric field.

[0102] Capacitance is the relative permittivity ε of the composite film. r The field is defined by the shape factor (A / d) multiplied by . The electric field polarizes the VDF-based composite film, i.e., orients the dipole along the VDF molecular chains. Therefore, two electrodes with area A are required to construct the desired electric field. Depending on the application and design specifications, the electrodes can be patterned into various shapes (rectangular, circular, or comb-shaped structures). Generally, electrodes include thin films of conductive metals (Ag, Au, Al, etc.), conductive polymers (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PDOT:PSS), etc.), conductive metal oxides (indium tin oxide (ITO), etc.), conductive silver nanoparticles / wires, or any combination thereof.

[0103] There are various techniques available for applying conductive materials to target substrates, and these include, but are not limited to: • Resistive heating of metals (Al, Ag, Au, etc.) in a vacuum chamber on a cooled substrate. • Magnetron sputtering of metal (such as Au) in a vacuum chamber on a cooled substrate (e.g., magnetron sputtering of Au for 30 seconds with a current of 60 mA, 2 layers), • Screen printing of conductive polymer and / or conductive silver nanoparticle inks. • Digital printing of conductive silver nanoparticle ink, and • Spray conductive silver nanoparticles / wire ink through a shadow mask.

[0104] As illustrated herein, the thin aluminum electrode is 10 -3The composite film was deposited by resistance heating in a vacuum chamber at a typical pressure of less than mbar. The composite film was aligned and fixed onto a polyethylene terephthalate / biaxially oriented polypropylene (PET / BOPP) liner, typically 25 μm to 50 μm thick. The composite film was then exposed to metal vapor. During metal deposition, the composite film was cooled to typically -30°C. This method, known as quench deposition, ensures that the temperature profile of the entire composite film is much lower than the melting point of the composite film. Deposition is carried out by a roll-to-roll process, allowing for the coating of a homogeneous metal of a specific length with minimal thickness variation. Shadow masks are not required for rectangular pattern formation. The width of the deposition is controlled by two mechanical shutter frames positioned very close to the substrate. If a pattern is required (e.g., circular electrodes), a shadow mask (made from a material such as PET) of the required pattern design is prepared by laser cutting. This patterned shadow mask is then placed on the surface of the composite film.

[0105] The thickness of the metal deposition is controlled by resistance heating power and deposition time, and monitored online by a quartz microbalance and / or optical density monitor. After the initial deposition, the chamber is pressurized with nitrogen gas, and the EAP composite film is carefully inverted to the opposite side of the back electrode. The shadow mask is also transferred and carefully aligned.

[0106] As illustrated herein, circular patterned aluminum electrodes were deposited on both sides of a thin composite film. The diameters of the circular patterned electrodes ranged from 25.4 mm to 1 / 4 inch. The thickness of the deposited aluminum film was 85 μm ± 5 μm, and the surface conductivity was 3 to 4 Ω.

[0107] If the total single capacitance value is measured and the total thickness of the film is known, the relative permittivity can be calculated as follows.

number

[0108] Balancing annealing and mechanical properties To maximize the piezoelectric response, it is desirable to maximize the crystallinity of the VDF copolymer film. This can be achieved by various annealing methods, including a step of recrystallization by melting the VDF copolymer and slowly cooling it to promote crystal nucleation and growth. However, as crystallinity increases, the monolithic VDF copolymer film may become brittle, and its ductility and toughness may decrease. As demonstrated here, reinforcing the VDF copolymer with a polymer film (such as ePTFE) can significantly improve the mechanical toughness after such an annealing process.

[0109] The relative crystallinity of a film can be determined by DSC measurement. The enthalpy of the solid-state transition between the ordered and disordered structures of the crystalline phase is directly related to crystallinity. As shown in Figure 2, annealing of a monolithic film increased its DSC enthalpy compared to an unannealed monolithic film (Example 1 vs. Example 2, Table 1). The enthalpy of a sample held at 155°C and slowly cooled was approximately 2.4 times greater than that of an unannealed film. This indicates approximately 2.4 times greater crystallinity. However, as shown in Figures 3 and 4, the ductility and mechanical toughness of the annealed monolithic film significantly decreased with increasing crystallinity.

[0110] Reinforcing a VDF-TrFE copolymer with the film of the present invention can improve its toughness after the annealing process. Referring to Table 1, the effect of annealing on this reinforced composite material increased the DSC enthalpy of the VDF copolymer (by approximately 2.5 times) (comparing Examples 3 and 4), and improved the mechanical performance when using ePTFE film 1 (an ePTFE film with higher strength in the mechanical direction than in the transverse direction). The DSC enthalpy and mechanical performance of the reinforced composite material using an ePTFE film with a more balanced strength profile (i.e., ePTFE film 2) are shown in Table 1, comparing Examples 5 and 6. Annealing increased crystallinity (by approximately 2.8 times), and balanced mechanical performance was observed in both the mechanical and transverse directions.

[0111] Test method Scanning electron microscope (SEM) - Preparation and imaging of cross-sectional samples SEM images were acquired using a field emission scanning electron microscope (ZEISS Gemini SEM 500, Zeiss International, Oberkochen, Germany). Cross-sectional samples were prepared using the cooled razor blade method and mounted on a 12.5 mm diameter metal stub using carbon double-sided adhesive pads (SpectroTabs, Plano GmbH, Wetzlar, Germany). The mounted samples were sputter-coated with platinum.

[0112] Thickness measurement The film thickness was determined from the cross-sectional SEM image.

[0113] Mass / composition measurement per unit area The mass per unit area was determined by measuring the mass of an 80 mm diameter circle cut from the film. The composition, i.e., the mass fraction of the electroactive VDF copolymer or terpolymer in the film, was determined from the ratio of the laydown of the VDF copolymer or terpolymer in the coating method to the measured mass per unit area of ​​the film.

[0114] Mechanical tensile test Static and dynamic mechanical tensile tests were performed on a Z050 universal testing machine (ZwickRoell GmbH & Co. KG, Ulm, Germany) equipped with a 200N load cell, and were controlled by the machine manufacturer's software (testXpert III) using the default parameters set by the manufacturer (ZwickRoell, listed above), unless otherwise specified.

[0115] In short, a rectangular sample with dimensions of (25.4 x 5) mm was prepared using a cutting tool and placed between clamping mechanisms using a sample loading tool from the outside. For static tension measurement, a preforce of 0.01 N and a constant linear tensile speed of 200 mm / min were used. The test was conducted at room temperature (approximately 21°C).

[0116] Dynamic testing was performed using the same testing machine and similar sample dimensions. A cyclic procedure consisting of 10 repeated cycles of periodic trapezoidal force loading was applied to the specimen. The setup was performed using the flexible programming language ZIMT (ZwickRoell Interpreter for Materials Testing, ZwickRoell, see above). A 1.5% elongation range within the elastic region was selected to obtain periodic force data.

[0117] Differential Scanning Calorimetry (DSC) Measurement DSC data were collected using a TA Instruments Q2000 DSC (TA Instruments, Newcastle, Delaware) at a heating rate of 10°C / min between -50°C and 155°C. Samples with a mass of approximately 7–8 mg were loaded into the sample holder for testing. The enthalpy of the solid-state transition was determined using the integration function included in the software.

[0118] DC voltage destructive method The test procedure conformed to ASTM D3755-97 (2004). In this method, more than 25 individual test points were brought into direct contact between electrodes made of metallized biaxially oriented polypropylene. A 3-mil thick Kapton film with a defined circular hole (or window) of 0.25 inches in diameter was placed on top of the test film to limit the location and size of the contact area. Contact to the film occurred only within the hole in the Kapton film, between the lower metallized polypropylene film and the upper metallized polypropylene film. Using an Associated Research Hypot Dielectric Analyzer Model 7720, the voltage was increased at 500 V / s until dielectric breakdown occurred, and the voltage was recorded at the point of dielectric breakdown. A continuous probability distribution (Wavell distribution function) was applied for data evaluation.

[0119] Electric polarization method The standard AC polarization method as described in the literature was used (Qiu et al., J. Appl. Phys. (2013), 113: 224106-1~224106-8). Using a modified Sawyer-Tower circuit (Qui et al., op. cit.) and combinations of unipolar and bipolar voltage waveforms, the polarization vs. electric field hysteresis curves of VDF-based copolymer / terpolymer composite films were recorded. Hysteresis is an essential feature of ferroelectric materials and can also be used to determine some of their main properties.

[0120] d 33 Measurement Station Piezoelectric coefficient d 33The piezoelectric coefficient d in the thickness direction was measured according to the Berlincourt method (Stewart M., Cain MG (2014) Direct Piezoelectric Measurement: The Berlincourt Method. In: Characterisation of Ferroelectric Bulk Materials and Thin Films. Springer Series in Measurement Science and Technology, Vol. 2, Cain, M (editor), Springer, Dordrecht). 33 To determine the piezoelectric coefficient, the sample is placed under an electrodynamic shaker and a static force of 3N is applied. The shaker vibrates at 2Hz, exerting a sinusoidal force with amplitude 1N. The charge generated by the piezoelectric effect of the sample is amplified by a charge amplifier and displayed on an oscilloscope. The dynamic force is measured by a force sensor and displayed on an oscilloscope. Using both curves, the piezoelectric coefficient was determined from the quotient of the charge signal and the dynamic force. Piezoelectric coefficient d 33 Also, commercially available piezometer systems that apply the Berlin Court method (d 33 The determination was made using a PiezoMeter System Model PM300 (Piezotest Pte. Ltd., Singapore). Simply put, the test sample is clamped and secured within the system, and a low-frequency force is applied. By processing the electrical signal from the sample and comparing it to a built-in reference, the system determines the d 33 It can be read directly.

[0121] Stretched polytetrafluoroethylene (ePTFE) membrane In this embodiment, the following ePTFE film was used.

[0122] "ePTFE film 1" - Preparation of ePTFE film The ePTFE film was manufactured according to the general teachings described in Bacino's U.S. Patent No. 5,476,589. The ePTFE film is similar to “ePTFE film 3” (see below), but has a surface density (mass / area) of approximately 3 g / m². 2 And it's expensive.

[0123] "ePTFE film 2" - Preparation of ePTFE film The ePTFE film was prepared according to the general teachings described in U.S. Patent No. 7,306,729 by Bacino et al. The ePTFE film had a mass of approximately 3.8 g / m². 2 The non-contact thickness was approximately 14.2 μm, the bubble point was approximately 481 kPa, the matrix tensile strength in the mechanical direction was approximately 343 MPa, and the matrix tensile strength in the transverse direction was approximately 268 MPa.

[0124] "ePTFE film 3" - Preparation of ePTFE film The ePTFE film was prepared according to the general teachings described in Bacino's U.S. Patent No. 5,476,589. The ePTFE film had a mass of approximately 2.1 g / m². 2 The non-contact thickness was approximately 7.4 μm, the bubble point was approximately 271 kPa, the matrix tensile strength in the mechanical direction was 1058 MPa, and the matrix tensile strength in the transverse direction was approximately 93.6 MPa.

[0125] "ePTFE membrane 4" - Preparation of structured ePTFE membrane The ePTFE film was prepared according to the general teachings described in U.S. Patent No. 7,306,729 by Bacino et al. The ePTFE film had a mass of approximately 0.2 g / m². 2 The non-contact thickness was approximately 1 μm, the bubble point was approximately 407 kPa, the matrix tensile strength in the mechanical direction was 734 MPa, and the matrix tensile strength in the transverse direction was approximately 755 MPa.

[0126] The ePTFE membrane was uniaxially structured in a 1:1.5 ratio in the transverse direction according to the teachings described in U.S. Patent No. 9,849,629 by Zaggl et al. After structuring, the densified membrane was moved to an absorption process.

[0127] Piezoelectric and ferroelectric polymers In this example, the following polymer resins were used. Poly(vinylidene fluoride-coated trifluoroethylene) A poly(vinylidene fluoride-co-trifluoroethylene) copolymer with piezoelectric, pyroelectric, and ferroelectric properties is used (SOLVENE® 250 / P300, Solvay SA Corp., Brussels, Belgium, CAS number 28960-88-5). The resin contains approximately 75 mol% VDF and 25 mol% TrFE. SOLVENE® 250 / P300 P(VDF-TrFE) copolymer has the following properties: Melting point 146℃ Average molecular weight: 300kDa Modulus of elasticity 1000 MPa Curie temperature: 116℃ Crystallization temperature: 120℃ Density (film): 1.7 g / cm³ 3 ε r (25℃; 1kHz): 11F·m -1 Breakdown voltage: >280V / μm Piezoelectric coefficient (d33): -24 pC / N at 110 Hz

[0128] Poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) terpolymer The poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer p(VDF-TrFE-CTFE) (SOLVENE® T EAP (Solvay SA Corp., Brussels, Belgium)) was used. This terpolymer contains approximately 63 mol% VDF, 28 mol% TrFE, and 9 mol% CTFE. The p(VDF-TrFE-CTFE) terpolymer is a high dielectric constant iron relaxer polymer. The p(VDF-TrFE-CTFE) terpolymer has the following properties: Melting point: 115℃ Average molecular weight: 300kDa Modulus of elasticity: 200 MPa Crystallization temperature: 85℃ Curie temperature: 16℃ Density (film): 1.7 g / cm³ 3 Breakdown voltage: >300V / μm ε r (25℃; 1kHz) 45 F·m -1

[0129] Application of electrodes to composite films Thin aluminum electrodes (circular, 15mm in diameter), 10 -3 The composite film was deposited by resistance heating in a vacuum chamber at a typical pressure of less than mbar. The composite film is typically positioned and fixed onto a PET / BOPP liner with a thickness of 25 μm to 50 μm. It is then exposed to metal vapor. During metal deposition, the film is typically cooled to -30°C. This method, known as quenching deposition, allows the temperature profile across the composite film to be much lower than the melting point of the composite film. Deposition is performed in a roll-to-roll process, allowing a homogeneous metal coating of a specific length with minimal thickness variation. Shadow masks are not required for rectangular pattern formation. The width of the deposition is controlled by two mechanical shutter frames positioned very close to the substrate. If a pattern is required (e.g., circular electrodes), a shadow mask (e.g., PET) with the required pattern design is prepared by laser cutting. This patterned shadow mask is placed on the surface of the composite film.

[0130] The thickness of the metal deposition is controlled by resistance heating power and deposition time, and monitored online by a quartz microbalance and / or optical density monitor. After the first deposition, the chamber is pressurized with nitrogen gas, the composite film is carefully inverted to the opposite side, and the second electrode is applied. The shadow mask is transferred and carefully positioned so that the two electrodes are aligned. The deposition thickness is typically in the range of 60–85 nm.

[0131] For hysteresis measurement, electrodes were attached to both sides of the sample. In corona-polarized samples, the electrodes were applied first after polarization. The method was the same as for electrodes used for hysteresis measurement. [Examples]

[0132] example Example 1 A solution of 10% by mass of poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin (SOLVENE® 250 / P300, Solvay SA Corp, above) and methyl ethyl ketone (MEK) was prepared by mixing the components and stirring at room temperature (nominal 24°C) for 4 hours. The obtained solution was applied directly to a carrier film using a slot die in a continuous roll-to-roll process. The film was dried in an in-line oven to remove the solvent. Cross-sectional SEM images of the monolithic cast film were collected and shown in Figure 1. The film thickness was approximately 3.6 μm when measured by SEM. Differential scanning calorimetry (DSC) analysis was performed. The DSC plot of the monolithic cast film is shown as Figure 2 (top). The enthalpy of the solid-state crystal transition obtained by integration was 8.7167 joules / gram. Tensile tests (elongation resistance) were performed on the monolithic cast film as described in the Test Methods section. Figure 3 (Example 1, solid line) shows the tensile test results of the monolithic cast film in the mechanical (downweb) direction (MD). Figure 4 (Example 1, solid line) shows the tensile test results of the monolithic cast film in the transverse (crossweb) direction (TD). Table 1 summarizes the characterization results of Example 1.

[0133] Example 2 The monolithic film from Example 1 was annealed by placing it in an oven set to 155°C for 10 minutes. Next, the oven was turned off and the film was left in the oven to cool slowly until it reached room temperature (nominal 24°C). A cross-sectional SEM image of the annealed film is shown in Figure 5. Here, the thickness of the annealed film is approximately 4.8 μm. A DSC was performed, and the plot of the results is shown in Figure 2 (Example 2, dashed line). The enthalpy of the solid-state crystal transition obtained by integration is approximately 22.051 J / g. The ratio of the enthalpy of the annealed film to the enthalpy of the unannealed monolithic film from Example 1 indicates that the crystallinity of the film increased 2.5 times due to the annealing treatment. A tensile test was performed as described in Example 1, and the elongation vs. force plots are shown in Figure 3 (mechanical direction, dashed line) and Figure 4 (transverse direction, dashed line). A voltage breakdown test was performed as described in the section on test methods above. The results of voltage breakdown are shown graphically in the wave plot in Figure 6, and the wave parameters α and β were determined. Electrical polarization measurements were performed as described in the section on test methods. The polarization results (electric field vs. polarization) are plotted in Figure 7. The characteristic data are summarized in Table 1.

[0134] Example 3 A 10% by mass solution of Example 1 (poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin dissolved in MEK) was applied to a microporous ePTFE film ("ePTFE film 1") using a slot die in a continuous roll-to-roll process. The solution uniformly wetted and filled the ePTFE film. The film was dried in an in-line oven to remove the solvent. The resulting composite film had a composition of 39% by mass of poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin and 61% by mass of ePTFE. A cross-sectional SEM image of the composite film is shown in Figure 8. DSC analysis was performed to measure the enthalpy (normalized). Tensile tests were performed to measure elongation vs. force (MD and TD). Voltage breakdown tests were performed to determine wave parameters α and β. The results of the characterization are summarized in Table 1.

[0135] Example 4 The composite film of Example 3 was annealed by placing it in an oven set to 155°C for 10 minutes. Next, the oven was turned off, and the film was left in the oven to cool slowly until it reached room temperature (nominal 24°C). A cross-sectional SEM image of the annealed composite film is shown in Figure 9. DSC analysis was performed to measure the enthalpy (normalized). Tensile tests were performed to measure elongation vs. force (MD and TD). Voltage breakdown tests were performed to measure wave parameters α and β. Electrical polarization measurements were performed, and the polarization results are shown in Figure 10. The characteristic data are summarized in Table 1.

[0136] Example 5 A 10% by mass solution of Example 1 (poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin dissolved in MEK) was directly coated onto a microporous ePTFE film ("ePTFE film 2") using a slide die in a continuous roll-to-roll process. The solution uniformly wetted and filled the ePTFE film. The film was dried in an in-line oven to remove the solvent. The composite film had a composition of 43 wt% poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin and 57 wt% ePTFE. A cross-sectional SEM image of the composite film is shown in Figure 11.

[0137] DSC analysis was performed to measure enthalpy (normalized). Tensile tests were conducted to measure elongation vs. force (MD and TD). Voltage breakdown tests were performed to determine wave parameters α and β. The characteristic data are summarized in Table 1.

[0138] Example 6 The composite film from Example 5 was annealed in an oven set to 155°C for 10 minutes. Next, the oven was turned off and the film was left in the oven to cool slowly until it reached room temperature (nominal 24°C).

[0139] DSC analysis was performed to measure enthalpy (normalized). Tensile tests were conducted to measure elongation vs. force (MD and TD). Voltage breakdown tests were performed to determine wave parameters α and β. Electrical polarization measurements were performed, and the polarization results are shown in Figure 12. Characteristic data are summarized in Table 1.

[0140] Example 7 The following example illustrates the preparation of a multilayer VDF-based copolymer film.

[0141] Monolithic films of poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin were manufactured using the general process of Example 1. ePTFE composite films containing poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin were manufactured according to Example 5. Multilayering of several VDF-based copolymer films was achieved by a two-step approach under temperature and pressure over specific residence times. For this purpose, a commercially available high-performance hot press (Model P200 S from COLLIN Lab & Pilot Solutions GmbH) was used. The hot plate was heated to 155°C, and the films were bonded under a pressure of 50 bar in both process steps.

[0142] First, monolithic films with ePTFE composite films were stacked and manually aligned. A high-temperature silicone rubber sheet (Silex Silicone LTD, Hampshire, UK HT60) was used as a liner to separate the stacked films from the hot plate and prevent surface irregularities between the polymer stack and the hot plate. Next, the positioned stack was compressed between the hot plates at 155°C and 50 bar for 30 minutes. The heating press was opened, and the two-layer bonded stack was allowed to cool slowly.

[0143] Next, one of the silicone liners was manually removed from one side of the two-layer stack, and the third layer (a monolithic film of poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin, e.g. 1) was placed on the surface of the VDF base of the two-layer stack. Again, the silicone liner was used to separate the stack sheets from the hot plate surface. The three-layer stack was compressed together using the same process parameters (155°C, 50 bar for 30 minutes).

[0144] The resulting multilayer composite film had a composition of 71 wt% poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin (Solvene® 250 / P300) and 19 wt% ePTFE. A cross-sectional SEM image of the three-layer film is shown in Figure 13. The results of the polarization experiment are shown in Figure 14. The characteristic data are summarized in Table 1.

[0145] Example 8 The components were mixed and stirred at room temperature (nominal 24°C) for 4 hours to prepare a solution of 10% by mass of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer p(VDF-TrFE-CTFE) (Solvene® T resin, Solvay SA Corp., above) and methyl ethyl ketone. The solution was applied to a microporous ePTFE film ("ePTFE film 2") using a slot die in a continuous roll-to-roll process. The solution uniformly wetted and filled the ePTFE film. The film was dried in an in-line oven to remove the solvent. The resulting composite film had a composition of 53 wt% p(VDF-TrFE-CTFE) (Solvene® T) and 47 wt% ePTFE. The composite film was annealed by placing it in an oven set to 125°C for 10 minutes. Next, the oven was turned off, and the film was left inside the oven to cool slowly over approximately 24 hours until it reached room temperature (nominal 24°C).

[0146] The thickness of the composite film was measured using cross-sectional SEM image analysis. Enthalpy (normalized) was measured using DSC analysis. Wave parameters α and β were determined by voltage breakdown testing. Electrical polarization measurements were performed, and the polarization results are shown in Figure 15. Characteristic data are summarized in Table 1.

[0147] Example 9 A 10% by mass solution of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer p(VDF-TrFE-CTFE) (SOLVENE® T resin, Solvay SA Corp, above) was prepared and coated onto ePTFE as described in Example 8, but the ePTFE film used was "ePTFE film 3". The solution uniformly wetted and filled the ePTFE film. The film was dried in an in-line oven to remove the solvent. The resulting composite film had a composition of 52 wt% p(VDF-TrFE-CTFE) (Solvene® T) and 48 wt% ePTFE. The composite film was placed in an oven set to 125°C and annealed for 10 minutes. The oven was then turned off and the film was left in the oven to cool slowly over approximately 24 hours until it reached room temperature (nominal 24°C).

[0148] The thickness of the composite film was determined using cross-sectional SEM image analysis. Enthalpy (normalized) was measured using DSC analysis. Wave parameters α and β were determined by voltage breakdown testing. Electrical polarization measurements were performed, and the polarization results are shown in Figure 16. Characteristic data are summarized in Table 2.

[0149] Example 10 Example 10 was processed in two steps. The microporous PTFE film ("ePTFE film 4") was uniaxially structured in a ratio of (1.0:1.5) in the transverse direction, as described in U.S. Patent No. 9,849,629 by Zaggl et al. A solution of 10% by mass of p(VDF-TrFE-CTFE) (Solvene® T resin, Solvay, above) and methyl ethyl ketone was prepared by mixing the components and stirring at room temperature (nominal 24°C) for 4 hours. The solution was applied to the microporous PTFE film structured in a continuous roll-to-roll process using a slot die. The composite film was annealed in an oven set to 125°C for 10 minutes. The oven was then turned off and the film was left in the oven to cool slowly for about 24 hours until it reached room temperature (nominal 24°C). The resulting composite film had a composition of 84 wt% VDF-based terpolymer and 16 wt% ePTFE.

[0150] The thickness of the composite film was determined using cross-sectional SEM image analysis. Electrical polarization measurements were performed, and the polarization results are shown in Figure 17. The characteristic data are summarized in Table 2.

[0151] Example 11 Example 11 was processed in two steps. The structured microporous PTFE film was prepared as described in Example 10. A solution of 10% by mass of p(VDF-TrFE-CTFE) (SOLVENE® T resin, Solvay, above) and methyl ethyl ketone was prepared by mixing the components and stirring at room temperature (nominal 24°C) for 4 hours. The p(VDF-TrFE-CTFE) solution was applied to this structured microporous PTFE film using a slot die in a continuous roll-to-roll process. The composite film was annealed and cooled as described in Example 10. The resulting composite film had a composition of 98 wt% VDF-based terpolymer and 2 wt% ePTFE.

[0152] The thickness of the composite film was determined using cross-sectional SEM image analysis. Electrical polarization measurements were performed, and the polarization results are shown in Figure 18. The characteristic data are summarized in Table 2.

[0153] Example 12 A composite ePTFE film containing p(VDF-TrFE-CTFE) was prepared and dried according to the method of Example 8, but with a high loading of VDF terpolymer. The resulting composite film had a composition of 60 wt% VDF terpolymer and 40 wt% ePTFE. The composite film was annealed in an oven set to 125°C for 30 minutes. Next, the oven was turned off and the film was left in the oven to cool slowly over approximately 24 hours until it reached room temperature (nominal 24°C). SEM images of the cross-section of the film are shown in Figure 19. The results of mechanical tensile tests in the mechanical direction (MD) and transverse direction (TD) are shown in Figure 20 (solid lines, Example 12). The results of the polarization experiment are shown in Figure 21. The characteristic data are summarized in Table 2.

[0154] Example 13 A composite ePTFE film containing p(VDF-TrFE-CTFE) was prepared and dried in the same manner as in Example 8, but with a different loading amount of VDF terpolymer. The resulting composite film had a composition of 47 wt% VDF terpolymer and 53 wt% ePTFE. The composite film was annealed and cooled as described in Example 12.

[0155] The thickness of the composite film was measured using cross-sectional SEM image analysis. Electrical polarization measurements were performed, and the polarization results are shown in Figure 22. The characteristic data are summarized in Table 2.

[0156] Example 14 Structured microporous PTFE membranes were prepared and dried using the methods described in Examples 10 and 11, but with a high-loading VDF terpolymer. The resulting structured composite film had a composition of 85 wt% VDF terpolymer and 15 wt% ePTFE. The structured composite film was annealed and cooled as described in Example 13.

[0157] The thickness of the composite film was measured using cross-sectional SEM image analysis. The results of mechanical tensile tests in the mechanical direction (MD) and transverse direction (TD) are shown in Figure 20 (dashed line, Example 14) and Figure 23. The results of the polarization experiment are shown in Figure 24. The characteristic data are summarized in Table 2.

[0158] Example 15 A five-layer composite material was created by fabricating a stacked multilayer film using the general heat compression process described in Example 7, with the modified process parameters described below. Briefly, five layers of the composite film from Example 13 (a composite ePTFE film containing p(VDF-TrFE-CTFE)) were aligned and stacked using a press. The top and bottom of the five-layer stack were separated from the hot plate surface using a silicone liner. A pressure of 0.17 bar (2.5 psi) was applied at a temperature of 110°C for 10 minutes. The press was opened and allowed to cool to room temperature (nominal 14°C). The five-layer composite film was annealed and cooled as described in Example 12. The resulting five-layer composite film had a composition of 47 wt% VDF terpolymer and 53 wt% ePTFE. An SEM image of the film cross-section is shown in Figure 25. The results of the polarization experiment are shown in Figure 26. The characteristic data are summarized in Table 2.

[0159] Example 16 A five-layer composite film was prepared using the structured ePTFE composite film from Example 14, as described in Example 15. Briefly, the five layers of the structured composite film from Example 14 were aligned and stacked using a press. A silicone liner was used to separate the upper and lower parts of the five-layer stack from the hot plate surface. Heat compression and annealing were performed as described in Example 15. The resulting five-layer composite film had a composition of 84 wt% VDF terpolymer and 6 wt% ePTFE.

[0160] The thickness of the 5-layer composite film was measured using cross-sectional SEM image analysis. The results of the polarization experiment are shown in Figure 27. The characteristic data are summarized in Table 2.

[0161] Example 17 A monolithic film of poly(vinylidene fluoride-co-trifluoroethylene) copolymer resin (SOLVENE® 250 / P300, Solvay SA Corp, cited above) was prepared and annealed according to the general process of Example 2.

[0162] The thickness of the monolithic film was determined using cross-sectional SEM image analysis. The characteristic data is summarized in Table 2.

[0163] Example 18 The following example describes the preparation and performance of a laminated three-layer composite film in which one ePTFE / VDF terpolymer composite film is sandwiched between two VDF copolymer monolithic films.

[0164] In short, a multilayer composite film was formed by symmetrically placing the VDF-based terpolymer composite film of Example 14 between two monolithic VDF copolymer films of Example 17 and using the general hot-press process described in Example 7. The bonding process itself was the same as the process described in Example 7 and was carried out in two steps using a hot press.

[0165] First, a two-layer film was prepared by stacking and bonding the ePTFE / VDF-based terpolymer composite film of Example 14 with the first monolithic film of Example 17 at 125°C and 50 bar. A silicone liner was used to separate the upper and lower parts of the two-layer stack from the hot plate surface. After this first lamination step, the resulting two-layer composite film was slowly cooled to room temperature (nominal 24°C). The support liner was carefully removed from the two-layer stack. The second monolithic film of Example 17 was manually aligned and bonded to the opposite side of the two-layer composite film (using the same temperature and pressure) to form a symmetrical three-layer composite material.

[0166] The resulting multilayer composite film, consisting of these three single layers, had a composition of 67 wt% p(VDF-TrFE) (SOLVENE® 250 / P300), 28 wt% p(VDF-TrFE-CTFE) (SOLVENE® T), and 5 wt% ePTFE. A cross-sectional SEM image of the three-layer film is shown in Figure 28. The approximate total thickness (16.46 μm) was determined by adding up the thicknesses of the individual layers measured by SEM. The results of the polarization experiment are shown in Figure 29. The characteristic data are summarized in Table 2. Table 1 Table 2 (Aspect) (Aspect 1) a. A composite film having a first surface and a second surface, i. Ferroelectric materials, and ii. Polymer-reinforced film, composite film, b. A first electrode electrically connected to the first surface of the composite film, and c. A second electrode electrically connected to the second surface of the composite film, Ferroelectric articles, including those containing such materials. (Aspect 2) The ferroelectric article according to embodiment 1, wherein the polymer-reinforced film includes a densified and / or shrinkable film containing macrostructured folded portions and / or microfolded fibrils. (Aspect 3) The ferroelectric article according to embodiment 1, wherein the ferroelectric material includes a ferroelectric polymer, a ferroelectric ceramic, or a combination thereof. (Aspect 4) The ferroelectric article according to any one of embodiments 1 to 3, wherein the ferroelectric polymer comprises a vinylidene difluoride (VDF) copolymer or a terpolymer. (Aspect 5) The ferroelectric polymer comprises one or more of the following: poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)(VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene)(P(VDF-TrFE-CTFE), poly(vinylidene fluoride-trifluoroethylene)(VDF-TrFE), or a combination thereof, as described in any one of embodiments 1 to 4. (Aspect 6) The aforementioned ferroelectric ceramics include barium strontium titanate (BST), barium zirconium titanate (BZT), PZT (lead, zirconium, titanium, oxygen), and PbTiO2. 3 (PT), Pb(Mg 1 / 3 Nb 2 / 3 )O 3 (PMN), Pb(Mg 1 / 3 Nb 2 / 3 )O 3 -PbTiO 3 (PMN-PT), LiTaO 3 A ferroelectric article according to any one of embodiments 1 to 5, comprising one or more of the above combinations. (Aspect 7) The ferroelectric article according to any one of embodiments 1 to 6, wherein the ferroelectric ceramic comprises one or more nanoparticles, nanowires, nanorods, nanocubes, nanofillers, or combinations thereof. (Pattern 8) The ferroelectric material is a ferroelectric article according to any one of embodiments 1 to 7, comprising a ferroelectric polymer and a ferroelectric ceramic particle filler. (Aspect 9) The ferroelectric article according to any one of embodiments 1 to 8, wherein the polymer-reinforced film comprises a microporous film having pores, and the microporous film comprises a polyolefin, a fluorinated polyolefin, or a combination thereof. (Aspect 10) The polymer-reinforced film comprises one or more of the following: ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), polyparaxylylene (PPX), vinylidene fluoride (VDF) copolymer (VDF-co-TFE or TrFE), ethylenetetrafluoroethylene (ETFE), poly(tetramethyl-p-sylphenylenesiloxane) (PTMPS), or a combination thereof, as described in any one of embodiments 1 to 9. (Aspect 11) The ferroelectric article according to any one of embodiments 1 to 10, wherein the polymer-reinforced film comprises an expandable polymer having a microstructure of interconnected nodes and void volumes defining a plurality of pores, an expandable polymer having a microstructure consisting substantially of fibrils and void volumes defining a plurality of pores, or a combination thereof. (Aspect 12) The ferroelectric article according to embodiment 11, wherein the expanded polymer comprises one or more of the following: expanded polytetrafluoroethylene (ePTFE), expanded ultra-high molecular weight polyethylene (ePE), expanded polyparaxylylene (ePPX), expanded VDF-co-TFE copolymer, expanded VDF-co-TrFE copolymer, expanded ethylenetetrafluoroethylene (eETFE), expanded poly(tetramethyl-p-sylphenylenesiloxane (ePTMPS)), or a combination thereof. (Aspect 13) The ferroelectric article according to embodiment 11 or 12, wherein the microstructure of nodes, fibrils, or combinations thereof of the expanded polymer is partially or completely coated with a conductive metal coating to define the coated microstructure, and furthermore, the coated microstructure retains at least a portion of the void volume after coating. (Aspect 14) The ferroelectric article according to any one of embodiments 1 to 13, wherein the ferroelectric material forms a coating on the reinforcing film. (Aspect 15) The ferroelectric article according to embodiment 11 or 12, wherein the ferroelectric material is partially or completely absorbed within the void volume of the reinforcing film. (Aspect 16) The ferroelectric polymer comprises one or more of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)), poly(vinylidene fluoride-trifluoroethylene) (VDF-TrFE), or a combination thereof, and further, the ferroelectric polymer is partially or completely absorbed within a reinforcing film of stretched ePTFE, the ferroelectric article according to any one of embodiments 1 to 15. (Aspect 17) The ferroelectric article according to any one of embodiments 1 to 16, wherein the composite film has a thickness of 1 μm or more and 20 μm or less. (Aspect 18) The ferroelectric article according to embodiment 17, wherein the composite film has a thickness of 1 μm or more and 10 μm or less. (Aspect 19) The polymer-reinforced film has a mass of 5 g / m² per unit area. 2 A ferroelectric article according to any one of the following embodiments 1 to 18. (Aspect 20) The polymer-reinforced film has a mass of 4 g / m² per unit area. 2 The ferroelectric article described in Embodiment 19 is as follows: (Aspect 21) The polymer-reinforced film has a mass of 3 g / m² per unit area. 2 The ferroelectric article described in Embodiment 19 is as follows: (Aspect 22) The composite film has a certain total mass, and furthermore, the composite film is a. A reinforcing film of 20 wt% or less based on the total mass of the composite film, and b. Based on the total mass of the composite film, 80 wt% or more of ferroelectric material, A ferroelectric article according to any one of embodiments 1 to 21, including the following: (Aspect 23) The composite film has a certain total mass, and furthermore, the composite film is a. A reinforcing film of 15 wt% or less based on the total mass of the composite film, and b. Based on the total mass of the composite film, 85 wt% or more of ferroelectric material, A ferroelectric article according to any one of embodiments 1 to 22, including the following: (Aspect 24) The composite film has a certain total mass, and furthermore, the composite film is a. A reinforcing film of 10 wt% or less based on the total mass of the composite film, and b. Based on the total mass of the composite film, 90 wt% or more of ferroelectric material, A ferroelectric article according to any one of embodiments 1 to 23, including the following: (Aspect 25) The reinforcing film is biaxially oriented, c. The tensile strength of the mechanical direction (MD) matrix is ​​at least 30 MPa, and d. The transverse (TD) matrix tensile strength is at least 30 MPa. A ferroelectric article according to any one of the descriptions 1 to 24. (Aspect 26) The ferroelectric article according to embodiment 19, wherein the ratio of the tensile strength of the MD matrix to the tensile strength of the TD matrix is ​​1.0:0.1 to 0.1:1.0. (Aspect 27) The ferroelectric article according to any one of embodiments 19 to 21, wherein the reinforcing film has a porosity of at least 30% as measured before the addition of the ferroelectric material. (Aspect 28) The upper electrode and / or lower electrode are a) A conductive metal layer of alumina with a thickness of 80 nm or less, b) A layer of conductive thermoplastic resin made of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), c) A layer of conductive ink containing silver nanoparticles or silver nanowire ink deposited by digital printing, spraying, or screen printing, Any combination of da, b, or c, A ferroelectric article according to any one of embodiments 1 to 27, including the following: (Aspect 29) The ferroelectric composite is a ferroelectric article according to any one of embodiments 1 to 28, comprising a plurality of composite films in a stacked configuration. (Aspect 30) The ferroelectric article according to embodiment 29, wherein the plurality of composite films include at least one laminated structure. (Aspect 31) A ferroelectric article according to embodiment 28 or 30, wherein at least one of the composite films in the stack configuration is different from at least one of the other composite films in the material. (Aspect 32) A ferroelectric article according to any one of embodiments 28 to 31, wherein at least one of the composite films in the stack configuration has a different thickness from at least one of the other films in the material. (Aspect 33) A ferroelectric article according to any one of embodiments 28 to 32, wherein at least one of the composite films in the stack configuration has a different strength from at least one of the other films in the material. (Aspect 34) A ferroelectric article according to any one of embodiments 27 to 31, wherein at least one of the composite films in the stack configuration is oriented differently from at least one of the other films in the material. (Aspect 35) A device comprising a ferroelectric article as described in any one of embodiments 1 to 34. (Aspect 36) A method for manufacturing a ferroelectric article, To provide a polymer-reinforced film having a first surface and a second surface, wherein the polymer-reinforced film has a microstructure of nodes interconnected by fibrils, or a microstructure consisting substantially only of fibrils, and the microstructure further defines void volumes that define a plurality of pores. Applying a ferroelectric material to the polymer-reinforced film to form a reinforced ferroelectric composite material. At least one first electrode is attached to the first surface, and To form a ferroelectric article by connecting at least one second electrode to the second surface, Methods that include...

Claims

1. a. A composite film having a first surface and a second surface, i. Ferroelectric materials, and ii. Polymer-reinforced film defining folded portions and / or folded fibrils within a microstructure, composite film, b. A first electrode electrically connected to the first surface of the composite film, c. A second electrode electrically connected to the second surface of the composite film, Ferroelectric articles, including those mentioned above.

2. The ferroelectric article according to claim 1, wherein the ferroelectric material includes a ferroelectric polymer, a ferroelectric ceramic, or a combination thereof.

3. The ferroelectric article according to claim 2, wherein the ferroelectric polymer comprises a vinylidene difluoride (VDF) copolymer or a terpolymer.

4. The ferroelectric article according to claim 2, wherein the ferroelectric polymer comprises one or more of the following: poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE), poly(vinylidene fluoride-trifluoroethylene) (VDF-TrFE), or a combination thereof.

5. The ferroelectric ceramic is barium strontium titanate (BST), barium zirconium titanate (BZT), PZT (lead, zirconium, titanium, oxygen), PbTiO ３ (PT), Pb(Mg １ / ３ Nb ２／３ )O ３ (PMN), Pb(Mg １／３ Nb ２ / ３ )O ３ -PbTiO ３ (PMN-PT), LiTaO ３ or one or more of combinations thereof, the ferroelectric article according to claim 2.

6. The ferroelectric article according to claim 2, wherein the ferroelectric ceramic comprises one or more of nanoparticles, nanowires, nanorods, nanocubes, nanofillers, or combinations thereof.

7. The ferroelectric article according to any one of claims 1 to 2, wherein the ferroelectric material comprises a ferroelectric polymer and a ferroelectric ceramic particle filler.

8. The ferroelectric article according to any one of claims 1 to 2, wherein the polymer-reinforced film comprises a microporous film having pores, and the microporous film comprises a polyolefin, a fluorinated polyolefin, or a combination thereof.

9. The ferroelectric article according to any one of claims 1 to 2, wherein the polymer-reinforced film comprises one or more of the following: ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), polyparaxylylene (PPX), vinylidene fluoride (VDF) copolymer (VDF-co-TFE or TrFE), ethylenetetrafluoroethylene (ETFE), poly(tetramethyl-p-sylphenylenesiloxane) (PTMPS), or a combination thereof.

10. The ferroelectric article according to any one of claims 1 to 2, wherein the polymer-reinforced film comprises an expandable polymer having a microstructure of interconnected nodes by fibrils and void volumes defining a plurality of pores, an expandable polymer having a microstructure consisting substantially of fibrils and void volumes defining a plurality of pores, or a combination thereof.

11. The ferroelectric article according to claim 10, wherein the expanded polymer comprises one or more of the following: expanded polytetrafluoroethylene (ePTFE), expanded ultra-high molecular weight polyethylene (ePE), expanded polyparaxylylene (ePPX), expanded VDF-co-TFE copolymer, expanded VDF-co-TrFE copolymer, expanded ethylenetetrafluoroethylene (eETFE), expanded poly(tetramethyl-p-sylphenylenesiloxane (ePTMPS)), or a combination thereof.

12. The ferroelectric article according to claim 10, wherein the microstructure of nodes, fibrils, or combinations thereof of the expanded polymer is partially or completely coated with a conductive metal coating to define the coated microstructure, and furthermore, the coated microstructure retains at least a portion of the void volume after coating.

13. The ferroelectric article according to any one of claims 1 to 2, wherein the ferroelectric material is coated on the polymer reinforcing film.

14. The ferroelectric article according to claim 10, wherein the ferroelectric material is partially or completely absorbed within the void volume of the polymer-reinforced film.

15. The ferroelectric article according to claim 2, wherein the ferroelectric polymer comprises one or more of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (VDF-TrFE-CFE), poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)), poly(vinylidene fluoride-trifluoroethylene) (VDF-TrFE), or a combination thereof, and further, the ferroelectric polymer is partially or completely absorbed within a reinforcing film of stretched ePTFE.

16. The ferroelectric article according to any one of claims 1 to 2, wherein the composite film has a thickness of 1 μm or more and 20 μm or less.

17. The ferroelectric article according to claim 16, wherein the composite film has a thickness of 1 μm or more and 10 μm or less.

18. The polymer-reinforced film has a mass of 5 g / m² per unit area. ２ The ferroelectric article according to any one of claims 1 to 2, which is as follows:

19. The polymer-reinforced film has a mass of 4 g / m² per unit area. ２ The ferroelectric article according to claim 18, which is as follows:

20. The polymer-reinforced film has a mass of 3 g / m² per unit area. ２ The ferroelectric article according to claim 18, which is as follows:

21. The composite film has a certain total mass, and furthermore, the composite film is a. A reinforcing film of 20 wt% or less based on the total mass of the composite film, and b. Based on the total mass of the composite film, 80 wt% or more of ferroelectric material, A ferroelectric article according to any one of claims 1 to 2, including the following:

22. The composite film has a certain total mass, and furthermore, the composite film is a. A reinforcing film of 15 wt% or less based on the total mass of the composite film, and b. A ferroelectric material of 85 wt% or more based on the total mass of the composite film, A ferroelectric article according to any one of claims 1 to 2, including the following:

23. The composite film has a certain total mass, and furthermore, the composite film is a. A reinforcing film of 10 wt% or less based on the total mass of the composite film, b. A ferroelectric material of 90 wt% or more based on the total mass of the composite film, A ferroelectric article according to any one of claims 1 to 2, including the following:

24. The polymer-reinforced film is biaxially oriented in the mechanical direction (MD) and the transverse direction (TD), and the matrix tensile strength in the mechanical direction is at least 30 MPa, and the matrix tensile strength in the transverse direction is at least 30 MPa. A ferroelectric article according to any one of claims 1 to 2.

25. The ferroelectric article according to claim 18, wherein the ratio of the matrix tensile strength in the mechanical direction to the matrix tensile strength in the transverse direction is 1.0:0.1 to 0.1:1.

0.

26. The ferroelectric article according to claim 18, wherein the polymer-reinforced film has a porosity of at least 30% as measured before the inclusion of the ferroelectric material.

27. The upper electrode and / or lower electrode are a) A layer of alumina with a thickness of 80 nm or less, b) A layer of conductive thermoplastic resin made of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), c) A layer of conductive ink containing silver nanoparticles or silver nanowire ink, d. Any combination of a, b, or c, A ferroelectric article according to any one of claims 1 to 2, including the following:

28. The ferroelectric article according to any one of claims 1 to 2, wherein the ferroelectric article comprises a plurality of composite films in a stacked configuration.

29. The ferroelectric article according to claim 28, wherein the plurality of composite films include at least one laminated structure.

30. A device comprising a ferroelectric article according to any one of claims 1 to 2.

31. A method for manufacturing a ferroelectric article, To provide a polymer-reinforced film having a first surface and a second surface, wherein the polymer-reinforced film has a microstructure of nodes interconnected by folded fibrils, or a microstructure consisting substantially only of folded fibrils, and the microstructure further defines void volumes defining a plurality of pores. A ferroelectric material is applied to the polymer-reinforced film by deposition or coating to form a reinforced ferroelectric composite. At least one first electrode is attached to the first surface of the reinforced ferroelectric composite, and To form a ferroelectric article by connecting at least one second electrode to the second surface of the reinforced ferroelectric composite, Methods that include...

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