Dielectric elastomer, method for preparing same, stretchable capacitor, and method for preparing same

Abstract

Provided is a method for preparing a dielectric elastomer, comprising the steps of: preparing a co-solvent; mixing the co-solvent and a polymer precursor to prepare a base source; mixing the base source and nanoparticles to prepare a dielectric elastomer source; and coating and curing the dielectric elastomer source on a support to prepare a dielectric elastomer in which a polymer formed from the polymer precursor surrounds the nanoparticles, wherein adjacent nanoparticles form clusters.

Description

Dielectric elastomer, method of manufacturing the same, flexible capacitor, and method of manufacturing the same

[0001] The present application relates to a dielectric elastomer, a method of manufacturing the same, a stretchable capacitor, and a method of manufacturing the same; more specifically, it relates to a dielectric elastomer, a method of manufacturing the same, a stretchable capacitor, and a method of manufacturing the same, wherein the dielectric elastomer distinguishes between stretching and pressure, wherein the capacitance is maintained when stretched and the capacitance is increased when pressurized.

[0002]

[0003] With the increasing demand for technologies such as wearable devices, body-attached sensors, and / or soft robots, the development of flexible capacitors is also actively underway.

[0004] For example, Korean Published Patent Application No. 10-2023-0126009 discloses a variable capacitor comprising a tubular dielectric body having a longitudinal through hole formed therein, a first electrically conductive coating layer formed by curing a liquid electrically conductive coating agent on the outer surface of the dielectric body, and a second electrically conductive coating layer formed by curing a liquid electrically conductive coating agent on the side of the through hole of the dielectric body, wherein the first coating layer is one electrode and the second coating layer is another electrode, and the first coating layer, the second coating layer, and the dielectric body constitute a single capacitor, and the dielectric body, the first coating layer, the first coating layer, and the second coating layer comprise silicone rubber having elasticity and stretchability, and wherein the capacitance of the capacitor changes due to an external force applied to the dielectric body in the longitudinal or thickness direction.

[0005] As another example, Korean Registered Patent Publication No. 10-1932816 discloses a method for manufacturing a flexible capacitor characterized by comprising the steps of: forming a dielectric layer on the surface of a conductor fiber; forming a conductor layer on the surface of a conductor / dielectric fiber; winding the conductor / dielectric / conductor fiber onto a core rod to form a coil shape; forming a flexible polymer part surrounding the conductor / dielectric / conductor coil wound on the core rod; and removing the core rod from the conductor / dielectric / conductor coil embedded in the flexible polymer part.

[0006] However, conventional stretchable capacitors may not be able to practically distinguish between stretching and pressure. When a stretchable capacitor is worn on the body, stretching and / or pressure may occur in the capacitor depending on the body's movements; however, stretchable capacitors developed to date may not be able to practically distinguish between the stretching and pressure generated by body movements.

[0007] Accordingly, conventional stretchable capacitors have limitations in signal interpretation capabilities and / or data reliability because they cannot effectively distinguish between signals resulting from stretching and pressure generated by the body. Furthermore, since conventional stretchable capacitors cannot effectively distinguish between stretching and pressure, they have limitations in that circuit performance degrades due to unwanted changes in capacitor performance when subjected to tension.

[0008]

[0009] The technical problem that the present application aims to solve is to provide a dielectric elastomer capable of distinguishing between stretching and pressure, a method for manufacturing the same, a stretchable capacitor, and a method for manufacturing the same.

[0010] Another technical problem that the present application aims to solve is to provide a dielectric elastomer, a method for manufacturing the same, a stretchable capacitor, and a method for manufacturing the same, wherein the capacitance is maintained when stretched.

[0011] Another technical problem that the present application aims to solve is to provide a dielectric elastomer, a method for manufacturing the same, a flexible capacitor, and a method for manufacturing the same, wherein the capacitance increases when pressurized.

[0012] The technical problems that this application aims to solve are not limited to those described above.

[0013]

[0014] To solve the above technical problem, the present application provides a method for manufacturing a dielectric elastomer.

[0015] According to one embodiment, the method for manufacturing a dielectric elastomer comprises the steps of: preparing a co-solvent; mixing the co-solvent with a polymer precursor to prepare a base source; mixing the base source with nanoparticles to prepare a dielectric elastomer source; and coating and curing the dielectric elastomer source on a support to produce a dielectric elastomer in which a polymer formed from the polymer precursor surrounds the nanoparticles, wherein adjacent nanoparticles may form a cluster.

[0016] According to one embodiment, the co-solvent comprises a dispersed solution and a non-dispersed solution, and can form the nanoparticles into the cluster.

[0017] According to one embodiment, the co-solvent comprises ethyl alcohol (EtOH), dichloromethane (DCM), or hexane (HX), the nanoparticle comprises at least one selected from the group of inorganic nanoparticles comprising barium titanate (BaTiO3), aluminum oxide (Al2O3), and silicon dioxide (SiO2), and the polymer precursor may comprise an ecoflex precursor.

[0018] According to one embodiment, when the co-solvent comprises the ethyl alcohol (EtOH) and the dichloromethane (DCM), the barium titanate (BaTiO3) may be provided in an amount greater than 18 wt% and less than 25 wt%, and when the co-solvent comprises the ethyl alcohol (EtOH) and the hexane (HX), the barium titanate (BaTiO3) may be provided in an amount greater than 18 wt% and less than 22 wt%.

[0019] According to one embodiment, prior to the coating, the method further includes a step of washing the support, wherein the washing step may include a step of boiling the support in a solution and a step of ultrasonically treating the boiled support.

[0020] According to one embodiment, prior to the coating, the method further includes a step of surface-treating the support, wherein the surface-treating step may include surface-treating the cleaned support with a release agent.

[0021]

[0022] According to one embodiment, the coating may be performed for more than 20 seconds and less than 1 minute in a rotating atmosphere of more than 250 rpm and less than 1000 rpm, and the curing may be performed for more than 30 minutes and less than 2 hours at a temperature of more than 50 ℃ and less than 100 ℃.

[0023] According to one embodiment, the coating and curing are performed in one cycle, and the cycle may be repeated multiple times.

[0024] According to one embodiment, the step of manufacturing the dielectric elastomer source may further include mixing in a surfactant.

[0025]

[0026] To solve the above technical problem, the present application provides a dielectric elastomer.

[0027] According to one embodiment, the dielectric elastomer comprises nanoparticles and a polymer surrounding the nanoparticles, wherein adjacent nanoparticles may form a cluster.

[0028] According to one embodiment, when the dielectric elastomer is stretched, the cluster is deformed into a T-shape while maintaining the capacitance, and when the dielectric elastomer is pressurized, the thickness of the dielectric elastomer decreases while increasing the capacitance.

[0029]

[0030] To solve the above technical problem, the present application provides a method for manufacturing a flexible capacitor.

[0031] According to one embodiment, the method for manufacturing the flexible capacitor may include the steps of: preparing a co-solvent; mixing the co-solvent with a polymer precursor to prepare a base source; mixing the base source with nanoparticles to prepare a dielectric elastomer source; coating and curing the dielectric elastomer source on a support to produce a dielectric elastomer comprising clusters formed from adjacent nanoparticles; detaching the dielectric elastomer from the support; and placing substrates on both sides with the dielectric elastomer in between to manufacture the flexible capacitor.

[0032] According to one embodiment, the substrate may include silver flakes or patterned copper.

[0033]

[0034] To solve the above technical problem, the present application provides a flexible capacitor.

[0035] According to one embodiment, the stretchable capacitor comprises a dielectric elastomer comprising nanoparticles and a polymer surrounding the nanoparticles, and substrates disposed on both sides between the dielectric elastomers, wherein adjacent nanoparticles in the dielectric elastomers form a cluster, and when stretched, the capacitance is maintained, and when pressurized, the capacitance is increased, and the Gauge Factor (GF) may be 0.

[0036]

[0037] According to an embodiment of the present application, a method for manufacturing a dielectric elastomer may be provided, comprising the steps of: preparing a co-solvent; mixing the co-solvent with a polymer precursor to prepare a base source; mixing the base source with nanoparticles to prepare a dielectric elastomer source; and coating and curing the dielectric elastomer source on a support to produce a dielectric elastomer in which a polymer formed from the polymer precursor surrounds the nanoparticles.

[0038] Accordingly, a dielectric elastomer may be provided comprising the nanoparticles and a polymer surrounding the nanoparticles, wherein adjacent nanoparticles form the cluster.

[0039] Furthermore, according to an embodiment of the present application, a flexible capacitor may be provided comprising substrates disposed on both sides with the dielectric elastic between them.

[0040] According to one embodiment, the cluster can be deformed from a spherical shape to an ellipsoidal shape when the dielectric elastic is stretched.

[0041] Accordingly, the capacitance of the above-mentioned flexible capacitor can be maintained.

[0042] According to one embodiment, the thickness of the dielectric elastomer may decrease when pressurized.

[0043] Accordingly, the capacitance of the above-mentioned flexible capacitor can be increased.

[0044] That is, the flexible capacitor according to the embodiment of the present application can distinguish between stretching and pressure.

[0045]

[0046] FIG. 1 is a drawing for explaining a method for manufacturing a dielectric elastomer according to an embodiment of the present application.

[0047] FIG. 2 is a drawing for explaining a method for manufacturing a co-solvent and a base source according to an embodiment of the present application.

[0048] FIG. 3 is a drawing for explaining a method for manufacturing a dielectric elastomer source according to an embodiment of the present application.

[0049] FIG. 4 is a drawing for illustrating a dielectric elastomer source coating according to an embodiment of the present application.

[0050] FIG. 5 is a drawing for explaining a dielectric elastomer according to an embodiment of the present application.

[0051] FIG. 6 is a drawing for explaining the stretching of a dielectric elastomer according to an embodiment of the present application.

[0052] FIG. 7 is a drawing for explaining a method for manufacturing a flexible capacitor according to an embodiment of the present application.

[0053] FIG. 8 is a drawing for explaining a flexible capacitor according to an embodiment of the present application.

[0054] FIG. 9 is a drawing for explaining the expansion and pressure of a flexible capacitor according to an embodiment of the present application.

[0055] FIG. 10 is a photograph of a dielectric elastomer before and after stretching, manufactured according to the experimental example of the present application.

[0056] FIG. 11 is a graph showing the cluster size of dielectric elastomers according to Experimental Example 1-1 and Experimental Example 1-2 of the present application.

[0057] FIG. 12 is a cluster photograph of a dielectric elastomer before and after stretching according to Experimental Example 1-1 of the present application.

[0058] FIG. 13 is a cluster photograph of a dielectric elastomer before and after stretching according to Experimental Example 1-2 of the present application.

[0059] FIG. 14 is a graph showing the stress-strain of dielectric elastic bodies according to Experimental Examples 2-1 to 2-7 of the present application.

[0060] FIG. 15 is a graph showing the stress-strain of dielectric elastomers according to Experimental Examples 3-1 to 3-7 of the present application.

[0061] FIG. 16 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 2-1 to 2-7 of the present application.

[0062] FIG. 17 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 3-1 to 3-7 of the present application.

[0063] FIG. 18 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 2-4 to 2-6 of the present application.

[0064] FIG. 19 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 3-4 to 3-6 of the present application.

[0065] FIG. 20 is a graph showing the gauge factor (GF) of a flexible capacitor according to Experimental Examples 2-1 to 2-7 of the present application.

[0066] FIG. 21 is a graph showing the gauge factor (GF) of a flexible capacitor according to Experimental Examples 3-1 to 3-7 of the present application.

[0067] FIG. 22 is a graph summarizing the gauge factor (GF) of the flexible capacitor according to Experimental Examples 2-1 to 2-7 and Experimental Examples 3-1 to 3-7 of the present application.

[0068] FIG. 23 is a graph showing the change in resistance of a flexible capacitor according to Experimental Examples 2-4 to 2-6 and Experimental Examples 3-4 to 3-6 of the present application.

[0069] FIG. 24 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 2-4 to 2-6 and Experimental Examples 3-4 to 3-6 of the present application.

[0070] FIG. 25 is a graph showing the gauge factor (GF) of a stretchable capacitor according to Experimental Examples 2-4 to 2-6 and Experimental Examples 3-4 to 3-6 of the present application.

[0071] FIG. 26 is a graph showing the change in capacitance over 100 cycles of a flexible capacitor according to Experimental Example 3-5 of the present application.

[0072] FIG. 27 is a graph showing the change in capacitance measured according to the movement of the body while wearing a flexible capacitor on the knee according to Experimental Example 3-5 of the present application.

[0073] FIG. 28 is a graph showing the change in capacitance measured according to the movement of the body while wearing a stretchable capacitor on the arm according to Experimental Example 3-5 of the present application.

[0074] FIG. 29 is a graph showing the signal measured by applying a flexible capacitor and a conventional capacitor according to Experimental Example 3-5 of the present application to a differentiator.

[0075] FIG. 30 is a graph showing the signal measured by applying a flexible capacitor and a conventional capacitor according to Experimental Example 3-5 of the present application to an integrator.

[0076] FIG. 31 is a graph showing the signal measured by applying a flexible capacitor and a conventional capacitor according to Experimental Example 3-5 of the present application to an RC circuit (resistor-capacitor circuit, RC circuit).

[0077]

[0078] Hereinafter, preferred embodiments of the present application will be described in detail with reference to the attached drawings. However, the technical concept of the present application is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the concept of the present application is sufficiently conveyed to those skilled in the art.

[0079] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of shapes and regions are exaggerated for the effective description of the technical content.

[0080] Additionally, although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. Accordingly, what is referred to as the first component in one embodiment may be referred to as the second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. Furthermore, in this specification, "and / or" is used to mean including at least one of the components listed before and after it.

[0081] In the specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, components, or combinations thereof described in the specification, and should not be understood as excluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. Additionally, in this specification, "connection" is used to include both indirectly connecting multiple components and directly connecting them.

[0082] Additionally, in the specification, the term "cluster" is used to include a group formed by adjacent nanoparticles.

[0083] Additionally, terms such as “part,” “device,” and “module” described in the specification refer to a unit that processes at least one function or operation, and this may be implemented in hardware, software, or a combination of hardware and software.

[0084] Furthermore, in describing the present application below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the application, such detailed description will be omitted.

[0085]

[0086] FIG. 1 is a drawing for explaining a method for manufacturing a dielectric elastomer according to an embodiment of the present application, FIG. 2 is a drawing for explaining a method for manufacturing a co-solvent and a base source according to an embodiment of the present application, FIG. 3 is a drawing for explaining a method for manufacturing a dielectric elastomer source according to an embodiment of the present application, FIG. 4 is a drawing for explaining a dielectric elastomer source coating according to an embodiment of the present application, FIG. 5 is a drawing for explaining a dielectric elastomer according to an embodiment of the present application, and FIG. 6 is a drawing for explaining the stretching of a dielectric elastomer according to an embodiment of the present application.

[0087] Referring to FIGS. 1 and FIGS. 2, a co-solvent (1) can be prepared (S110).

[0088] According to one embodiment, the co-solvent (1) may include a dispersion solution and a non-dispersion solution. In other words, the co-solvent (1) may be a mixed solvent of the dispersion solution and the non-dispersion solution.

[0089] As a result, the nanoparticles (4, see FIG. 5) described later can be formed into a cluster (120).

[0090] The dispersion solution may be, for example, ethyl alcohol (EtOH), and the non-dispersion solution may be, for example, dichloromethane (DCM) or hexane (HX). However, it is not limited thereto.

[0091] More specifically, for example, the above co-solvent (1) may be at least one selected from solvents having various polarities as shown in Table 1 below. However, it is not limited thereto.

[0092] Solvent Polarity Index (P') Hexane (HX) 0.1 Cyclohexane 0.1 Toluene 2.4 Dichloromethane (DCM) 3.1 Isopropanol 3.9 Tetrahydrofuran 4 Ethanol (EtOH) 4.3 Ethyl acetate 4.4 Acetone 5.1 Methanol 5.1 Acetonitrile 5.8 Water 10.2

[0093]

[0094] According to one embodiment, the larger the difference in polarity index between the solvents included in the co-solvent (1), the larger the size of the cluster (120) formed. More specifically, for example, in Table 1, when the co-solvent (1) includes ethyl alcohol (EtOH) and dichloromethane (DCM), the difference in polarity index is 1.2, and when the co-solvent (1) includes ethyl alcohol (EtOH) and hexane (HX), the difference in polarity index may be 4.2.

[0095] Accordingly, the size of the cluster (120) formed may be larger when the above co-solvent (1) includes the ethyl alcohol (EtOH) and the hexane (HX), which have a greater difference in polarity index.

[0096] Referring further to FIGS. 1 and FIGS. 2, the above co-solvent (1) and polymer precursor (2) are mixed to produce a base source (3) (S120).

[0097] According to one embodiment, the polymer precursor (2) may be formed from a polymer (110, see FIG. 5) described later and may surround the nanoparticle (4). The polymer precursor (2) may be, for example, a silicon-based polymer precursor or an organic-based polymer precursor. More specifically, for example, the polymer precursor (2) may be an ecoflex precursor. However, it is not limited thereto.

[0098] Referring further to FIGS. 1 and FIGS. 3, the base source (3) and nanoparticles (4) can be mixed to produce a dielectric elastomer source (10) (S130). The nanoparticles (4) may be at least one selected from the group of inorganic nanoparticles including, for example, barium titanate (BaTiO3), aluminum oxide (Al2O3), and silicon dioxide (SiO2). More specifically, for example, when the co-solvent (1) includes the ethyl alcohol (EtOH) and the dichloromethane (DCM), the barium titanate (BaTiO3) as the nanoparticles (4) may be mixed in an amount greater than 18 wt% and less than 25 wt%. For example, in more detail, when the co-solvent (1) comprises the ethyl alcohol (EtOH) and the dichloromethane (DCM), the barium titanate (BaTiO3) as the nanoparticle (4) can be mixed in an amount of 20 wt% or 22 wt%.

[0099] As a result, the dielectric elastomer (100, see FIG. 5) being manufactured may include small clusters (120).

[0100] Accordingly, the dielectric elastomer (100) manufactured can have excellent flexibility and elasticity.

[0101] Furthermore, in the same manner as the example described above, that is, when the co-solvent (1) comprises the ethyl alcohol (EtOH) and the dichloromethane (DCM) and the barium titanate (BaTiO3) is mixed as the nanoparticle (4) at 20 wt% or 22 wt%, the stretchable capacitor (1000) manufactured may have a gauge factor (GF) of 0.

[0102] According to one embodiment, the gauge factor (GF) is expressed by the following formula and may be an important parameter indicating sensitivity to mechanical deformation in a capacitor, such as a strain gauge or a strain-sensitive capacitor.

[0103] GF = △C / C0ε

[0104] Here, C0 represents the initial capacitance before deformation, ε represents the strain, and △C represents the changed capacitance after deformation. For example, if the capacitor has a gauge factor (GF) greater than 1, the capacitor is very sensitive to deformation, so even a small deformation can result in a large change in capacitance. As another example, if the capacitor has a gauge factor (GF) of 1, the capacitance may change in direct proportion to the deformation. As yet another example, if the capacitor has a gauge factor (GF) less than 1, the capacitor is less sensitive to deformation and may show a small change. As yet another example, if the capacitor has a gauge factor (GF) of 0, the capacitance may decrease upon deformation, and such a decrease in capacitance can be observed, for example, in a special-purpose sensor.

[0105] In other words, when a capacitor has a high gauge factor (GF), it has high sensitivity to deformation detection, enabling precise measurements; however, due to this high deformation sensitivity, there is a high possibility of malfunction in unstable environments, such as those with unstable temperature or pressure. On the other hand, when a capacitor has a low gauge factor (GF), it is insensitive to deformation, allowing for the maintenance of an accurate and stable signal.

[0106] In particular, when the gauge factor (GF) of the capacitor is 0, the capacitor can distinguish between expansion and contraction.

[0107] In other words, when the gauge factor (GF) of the capacitor is 0, the capacitance is maintained when stretched, and when pressurized, the capacitance can be increased. According to an embodiment of the present application, when the co-solvent (1) includes the ethyl alcohol (EtOH) and the dichloromethane (DCM) and the barium titanate (BaTiO3) is mixed as the nanoparticle (4) at 20 wt% or 22 wt%, the stretchable capacitor (1000) manufactured can distinguish between stretch and pressure because the gauge factor (GF) is 0.

[0108] In other words, since the gauge factor (GF) of the above-mentioned flexible capacitor (1000) is 0, when it is stretched, the capacitance is maintained, and when it is pressurized, the capacitance can be increased.

[0109] For another example, when the co-solvent (1) includes the ethyl alcohol (EtOH) and the hexane (HX), the barium titanate (BaTiO3) as the nanoparticle (4) may be mixed in an amount greater than 18 wt% and less than 22 wt%. More specifically, for example, when the co-solvent (1) includes the ethyl alcohol (EtOH) and the hexane (HX), the barium titanate (BaTiO3) as the nanoparticle (4) may be mixed in an amount of 20 wt%.

[0110] As a result, the dielectric elastomer (100) being manufactured may contain large clusters. Additionally, the dielectric elastomer (100) being manufactured may have a high density of clusters.

[0111] Accordingly, the dielectric elastomer (100) manufactured may have excellent stability and elasticity. More specifically, the dielectric elastomer (100) may have excellent frequency resonance stability and long-term cycle stability.

[0112] Furthermore, when the above co-solvent (1) includes the ethyl alcohol (EtOH) and the hexane (HX), and the barium titanate (BaTiO3) is mixed as the nanoparticle (4) at 22 wt%, the manufactured flexible capacitor (1000) may have a gauge factor (GF) of 0.

[0113] Accordingly, the manufactured flexible capacitor (1000) can distinguish between stretching and pressure.

[0114] In other words, since the gauge factor (GF) of the above-mentioned flexible capacitor (1000) is 0, when it is stretched, the capacitance is maintained, and when it is pressurized, the capacitance can be increased.

[0115] According to one embodiment, in the preparation of the dielectric elastomer source, a surfactant, for example, an amphoteric surfactant, a nonionic surfactant, a cationic surfactant, or an anionic surfactant may be further mixed.

[0116] Accordingly, the dispersion of the polymer precursor (2) and the nanoparticle (4) in the dielectric elastomer source (10) being manufactured can be controlled.

[0117] As a result, clusters (120) are easily formed in the dielectric elastomer (100, see FIG. 5) being manufactured, and the capacitance of the flexible capacitor (1000) containing the dielectric elastomer (100) can be stably maintained.

[0118] Referring further to FIGS. 1 and FIGS. 4, the support (sp) can be cleaned (S140). The support (sp) may be, for example, a glass substrate or an oxide substrate, for example, a silica (SiO2) substrate, but is not limited thereto, and is not limited to any support that enables coating and curing of the provided dielectric inertial source (10).

[0119] According to one embodiment, the support (sp) can be washed by boiling. More specifically, for example, the support (sp) can be washed by boiling in an acetone solution.

[0120] According to one embodiment, the boiled support (sp) can be ultrasonically treated. More specifically, for example, the boiled support (sp) can be ultrasonically treated sequentially using water, acetone, and isopropyl alcohol in that order.

[0121] Accordingly, foreign substances on the surface of the support (sp) are minimized, and the dielectric elastomer source (10) can be uniformly coated on the support (sp).

[0122] Referring further to FIG. 1 and FIG. 4, the support (sp) can be surface treated (S150).

[0123] According to one embodiment, the washed support (sp) may be surface-treated with a release agent. More specifically, for example, the washed support (sp) may be surface-treated with Ease Release 200 (ER-200).

[0124] Accordingly, when the dielectric elastomer source (10) is coated and cured on the support (sp) to produce a dielectric elastomer (100), the dielectric elastomer (100) can be easily detached from the support (sp).

[0125] Referring further to FIGS. 1, 4, and 5, the dielectric elastomer source (10) is coated and cured on the support (sp) so that a dielectric elastomer (100) in which a polymer (110) formed from the polymer precursor (2) surrounds the nanoparticle (4) can be manufactured (S160).

[0126] According to one embodiment, the coating may be performed in a film manufacturing process. Specifically, for example, the coating may be spin coating. More specifically, for example, the coating may be performed for more than 20 seconds and less than 1 minute in a rotating atmosphere of more than 250 rpm and less than 1000 rpm. However, it is not limited thereto.

[0127] According to one embodiment, the curing may be performed at a predetermined temperature for a predetermined time. More specifically, for example, the curing may be performed at a temperature greater than 50°C and less than 100°C for more than 30 minutes and less than 2 hours. However, it is not limited thereto.

[0128] According to one embodiment, the coating and the curing may be performed in a cycle, and the cycle may be repeated multiple times. More specifically, for example, the cycle may be repeated twice. However, it is not limited thereto.

[0129] Thus, a dielectric elastomer (100) according to the experimental example of the present application can be manufactured. Referring to FIGS. 5 and 6, the dielectric elastomer (100) may include the nanoparticle (4) and a polymer (110) surrounding the nanoparticle (4). In the dielectric elastomer (100), adjacent nanoparticles (4) may form a cluster (120).

[0130] According to one embodiment, the cluster (120) can be deformed from a spherical shape to an ellipsoidal shape when the dielectric elastic body (100) is stretched, as shown in FIG. 6.

[0131] Accordingly, the capacitance of the flexible capacitor (1000) including the dielectric elastic body (100) can be maintained.

[0132] According to one embodiment, the dielectric elastic body (100) may have its thickness reduced when pressurized.

[0133] Accordingly, the capacitance of the flexible capacitor (1000) including the dielectric elastic body (100) can be increased.

[0134]

[0135] Next, a flexible capacitor including the dielectric elastomer (100) and a method for manufacturing the same are described.

[0136] FIG. 7 is a drawing for explaining a method for manufacturing a flexible capacitor according to an embodiment of the present application, FIG. 8 is a drawing for explaining a flexible capacitor according to an embodiment of the present application, and FIG. 9 is a drawing for explaining the stretching and pressurization of a flexible capacitor according to an embodiment of the present application.

[0137] Referring to FIG. 7, the method for manufacturing the flexible capacitor (1000) may include steps S110 to S160 described above. Regarding steps S110 to S160, the description of the preceding embodiment will be referenced.

[0138] Referring further to FIG. 7, the dielectric elastomer (100) can be detached from the support (sp) (S170).

[0139] As previously described, since the support (sp) is surface-treated with the release agent, the dielectric elastomer (100) can be easily detached from the support (sp).

[0140] Referring further to FIGS. 7 and 8, substrates (200) are placed on both sides with the dielectric elastomer (100) in between, and the flexible capacitor (1000) can be manufactured (S180).

[0141] According to one embodiment, the substrate (200) may include silver flakes. When the substrate (200) includes the silver flakes, a silver substrate source may be prepared first in order to manufacture the substrate (200). Specifically, for example, 2-methyl-4-pentanone (MIBK) may be added to a precursor mixed with Ecoflex A and B, and after stirring, the silver flakes may be added and stirred to prepare the silver substrate source. More specifically, for example, 2.3g of 2-methyl-4-pentanone (MIBK) may be added to 1.6g of a precursor mixed with Ecoflex A and B in a mass ratio of 1:1, and after stirring for 30 minutes, the silver flakes may be added and stirred for 2 hours to prepare the silver substrate source. However, it is not limited to this.

[0142] According to one embodiment, the silver substrate source can be heated to remove residual solution and cured after being applied onto a mask. More specifically, for example, the silver substrate source can be applied by screen printing onto a stainless steel plate mask in the form of a thin film, then heated at 90°C for 1 hour to remove residual solution and cured at 120°C for 1 hour. However, it is not limited thereto.

[0143] Thus, a substrate (200) containing the above silver flakes can be manufactured.

[0144] According to one embodiment, the substrate (200) may include a patterned copper. When the substrate (200) includes the patterned copper, a laser may be irradiated onto a copper foil to form the patterned copper. More specifically, for example, a 17 μm copper foil may be irradiated with an ultraviolet laser to form the patterned copper.

[0145] Thus, a substrate (200) including the copper pattern can be manufactured.

[0146] Referring to FIG. 8, the substrate (200) including the silver flake or the substrate (200) including the copper pattern may be placed on both sides with the dielectric elastomer (100) in between.

[0147] Thus, a flexible capacitor (1000) according to an embodiment of the present application can be manufactured.

[0148] Referring to FIGS. 5 and 8, the stretchable capacitor (1000) may include the dielectric elastomer (100), which comprises the nanoparticle (4) and a polymer (110) surrounding the nanoparticle (4), and the substrate (200) positioned on both sides between the dielectric elastomer (100). Referring to FIGS. 5 and 6, in the dielectric elastomer (100), adjacent nanoparticles (4) may form a cluster (120), and the cluster (120) may be deformed from spherical to ellipsoidal when the dielectric elastomer (100) is stretched.

[0149] Accordingly, the capacitance of the above-mentioned flexible capacitor (1000) can be maintained.

[0150] According to one embodiment, the dielectric elastic body (100) may have its thickness reduced when pressurized.

[0151] Accordingly, the capacitance of the above flexible capacitor (1000) can be increased.

[0152] This may be because, as previously described, the flexible capacitor (1000) is manufactured by including the ethyl alcohol (EtOH) and the dichloromethane (DCM) as the co-solvent (1), and mixing the barium titanate (BaTiO3) as the nanoparticle (4) at 20 wt% or 22 wt%.

[0153] This may be because the above-mentioned flexible capacitor (1000) has a gauge factor (GF) of 0.

[0154] Alternatively, as previously described, the flexible capacitor (1000) may be manufactured by including the ethyl alcohol (EtOH) and the hexane (HX) as the co-solvent (1) and mixing the barium titanate (BaTiO3) at 20 wt% as the nanoparticle (4).

[0155] This may be because the above-mentioned flexible capacitor (1000) has a gauge factor (GF) of 0.

[0156] In other words, referring to FIG. 9, since the stretchable capacitor (1000) has a gauge factor (GF) of 0, when stretched, the capacitance is maintained, and when stretch pressure is applied, the capacitance can be increased.

[0157]

[0158] Specific experimental examples and characteristic evaluation results according to the embodiments of the present application are described below.

[0159]

[0160] Preparation of dielectric elastomer (ex1-1, EtOh / DCM) according to Experimental Example 1-1

[0161] Ethyl alcohol (EtOH) and dichloromethane (DCM) were provided in a mass ratio of 9:2 inside a container and stirred until a uniform liquid was formed at room temperature to prepare the co-solvent (1).

[0162] Ecoflex A and B were mixed in a mass ratio of 1:1 as the polymer precursor (2), and 3 g of the polymer precursor (2) and 1.5 g of the co-solvent (1) were stirred at 300 rpm for 5 minutes to produce the base source (3).

[0163] To the base source (3), 5, 10, 15, 18, 20, 22, and 25 wt% of the barium titanate (BaTiO3) as the nanoparticle (4) was added, and the mixture was stirred at 800 rpm for 10 minutes to produce the dielectric elastomer source (10).

[0164] A glass substrate was boiled and washed in an acetone solution using the above support (sp), and the boiled support (sp) was ultrasonically treated sequentially using water, acetone, and isopropyl alcohol in that order.

[0165] After surface-treating the washed support (sp) with Ease Release 200 (ER-200), the dielectric elastomer source (10) was coated on the support (sp) at 500 rpm for 30 seconds, the residual solution was removed in a vacuum atmosphere for 20 minutes, and the cycle of curing at 60°C for 1 hour was repeated twice to produce a dielectric elastomer (ex1-1, EtOh / DCM) according to Experimental Example 1-1.

[0166]

[0167] Preparation of dielectric elastomer (ex1-2, EtOh / HX) according to Experimental Example 1-2

[0168] In the above-described Experimental Example 1-1, ethyl alcohol (EtOH) and hexane (HX) were provided in a mass ratio of 3:1 to prepare the co-solvent (1), and a dielectric elastomer (ex1-2, EtOH / HX) according to Experimental Example 1-2 was prepared.

[0169]

[0170] Experimental Example 1-1 and Experimental Example 1-2 described above can be summarized as shown in Table 2 below.

[0171]

[0172] Compound (1) Experiment Example 1-1 (ex1-1, EtOh / DCM) Etyl alcohol (EtOH) and dichloromethane (DCM) Experiment Example 1-2 (ex1-2, EtOh / HX) Etyl alcohol (EtOH) and hexane (HX)

[0173]

[0174] FIG. 10 is a photograph of a dielectric elastomer (ex1-2, EtOh / HX) before and after stretching according to Experimental Example 1-2 of the present application.

[0175] Referring to FIG. 10(a), the appearance of a dielectric elastomer (ex1-2, EtOh / HX) before stretching can be seen, prepared according to Experimental Example 1-2 by including the ethyl alcohol (EtOH) and the hexane (HX) as the co-solvent (1) and mixing 20 wt% of the barium titanate (BaTiO3) as the nanoparticle (4). Referring to FIG. 10(b), the appearance of a dielectric elastomer (ex1-2, EtOh / HX) after stretching according to Experimental Example 1-2 can be seen.

[0176] Through FIG. 10, it can be seen that the dielectric elastomer (100) manufactured according to the experimental example of the present application has excellent elasticity.

[0177]

[0178] Figure 11 is a graph showing the degree of aggregation measured by adding 0.1 wt% of barium titanate (BaTiO3) to each co-solvent according to the experimental example of the present application.

[0179] At this time, the polymer precursor (2) was not mixed.

[0180] Referring to FIG. 11, it can be seen that the cluster (120) is larger in the co-solvent of Experimental Example 1-2 (ex1-2, EtOh / HX) than in the co-solvent of Experimental Example 1-1 (ex1-1, EtOh / DCM).

[0181] Thus, it can be proven that the size of the cluster (120) formed is larger when the above co-solvent (1) includes the ethyl alcohol (EtOH) and the hexane (HX), which have a greater difference in polarity index.

[0182]

[0183] FIG. 12 is a cluster photograph of a dielectric elastomer before and after stretching according to Experimental Example 1-1 of the present application, and FIG. 13 is a cluster photograph of a dielectric elastomer before and after stretching according to Experimental Example 1-2 of the present application.

[0184] Referring to Fig. 12(a), the appearance of the dielectric elastomer (ex1-1, EtOh / DCM) according to Experimental Example 1-1 before stretching can be seen, and referring to Fig. 12(b), the appearance of the dielectric elastomer (ex1-1, EtOh / DCM) according to Experimental Example 1-1 after stretching can be seen. At this time, the mixing amount of the barium titanate (BaTiO3) was 18 wt%.

[0185] Referring to Fig. 13(a), the appearance of the dielectric elastomer (ex1-2, EtOh / HX) according to Experimental Example 1-2 before stretching can be seen, and referring to Fig. 13(b), the appearance of the dielectric elastomer (ex1-2, EtOh / HX) according to Experimental Example 1-2 after stretching can be seen.

[0186] Through FIGS. 12 and 13, it can be seen that when the dielectric elastomer according to Experimental Example 1-1 (ex1-1, EtOh / DCM) and the dielectric elastomer according to Experimental Example 1-2 (ex1-2, EtOh / HX) are stretched, the cluster (120) is deformed from spherical to ellipsoidal.

[0187]

[0188] Preparation of dielectric elastomer (ex2-1, DCM5) according to Experimental Example 2-1

[0189] In the above-described Experimental Example 1-1, 5 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-1, DCM5) according to Experimental Example 2-1.

[0190]

[0191] Preparation of dielectric elastomer (ex2-2, DCM10) according to Experimental Example 2-2

[0192] In the above-described Experimental Example 1-1, 10 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-2, DCM10) according to Experimental Example 2-2.

[0193]

[0194] Preparation of dielectric elastomer (ex2-3, DCM15) according to Experimental Example 2-3

[0195] In the above-described Experimental Example 1-1, 15 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-3, DCM15) according to Experimental Example 2-3.

[0196]

[0197] Preparation of dielectric elastomer (ex2-4, DCM18) according to Experimental Example 2-4

[0198] In the above-described Experimental Example 1-1, 18 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-4, DCM18) according to Experimental Example 2-4.

[0199]

[0200] Preparation of dielectric elastomer (ex2-5, DCM20) according to Experimental Example 2-5

[0201] In the above-described Experimental Example 1-1, 20 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-5, DCM20) according to Experimental Example 2-5.

[0202]

[0203] Preparation of dielectric elastomer (ex2-6, DCM22) according to Experimental Example 2-6

[0204] In the above-described Experimental Example 1-1, 22 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-6, DCM22) according to Experimental Example 2-6.

[0205]

[0206] Preparation of dielectric elastomer (ex2-7, DCM25) according to Experimental Example 2-7

[0207] In the above-described Experimental Example 1-1, 25 wt% of the barium titanate (BaTiO3) was added to the nanoparticles (4) to produce a dielectric elastomer (ex2-7, DCM25) according to Experimental Example 2-7.

[0208]

[0209] Experimental Examples 2-1 to 2-7 described above can be summarized as shown in Table 3 below.

[0210] Classification Solvent (1) Nanoparticle (4) Content (wt%) Experiment Example 2-1 (ex2-1, DCM5) Ethyl alcohol (EtOH) and dichloromethane (DCM) 5 Experiment Example 2-2 (ex2-2, DCM10) Ethyl alcohol (EtOH) and dichloromethane (DCM) 10 Experiment Example 2-3 (ex2-3, DCM15) Ethyl alcohol (EtOH) and dichloromethane (DCM) 15 Experiment Example 2-4 (ex2-4, DCM18) Ethyl alcohol (EtOH) and dichloromethane (DCM) 18 Experiment Example 2-5 (ex2-5, DCM20) Ethyl alcohol (EtOH) and dichloromethane (DCM) 20 Experiment Example 2-6 (ex2-6, DCM22) Ethyl alcohol (EtOH) and dichloromethane (DCM) 22 Experiment Example 2-7 (ex2-7, DCM25) Ethyl alcohol (EtOH) and dichloromethane (DCM)25

[0211]

[0212] Preparation of dielectric elastomer (ex3-1, HX5) according to Experimental Example 3-1

[0213] In the above-described experimental example 1-2, 5 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to prepare a dielectric elastomer (ex3-1, HX5) according to experimental example 3-1.

[0214]

[0215] Preparation of dielectric elastomer (ex3-2, HX10) according to Experimental Example 3-2

[0216] In the above-described experimental example 1-2, 10 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to prepare a dielectric elastomer (ex3-2, HX10) according to experimental example 3-2.

[0217]

[0218] Preparation of dielectric elastomer (ex3-3, HX15) according to Experimental Example 3-3

[0219] In the above-described experimental example 1-2, 15 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to produce a dielectric elastomer (ex3-3, HX15) according to experimental example 3-3.

[0220]

[0221] Preparation of dielectric elastomer (ex3-4, HX18) according to Experimental Example 3-4

[0222] In the above-described experimental example 1-2, 18 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to produce a dielectric elastomer (ex3-4, HX18) according to experimental example 3-4.

[0223]

[0224] Preparation of dielectric elastomer (ex3-5, HX20) according to Experimental Example 3-5

[0225] In the above-described experimental example 1-2, 20 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to produce a dielectric elastomer (ex3-5, HX20) according to experimental example 3-5.

[0226]

[0227] Preparation of dielectric elastomer (ex3-6, HX22) according to Experimental Example 3-6

[0228] In the above-described experimental example 1-2, 22 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to produce a dielectric elastomer (ex3-6, HX22) according to experimental example 3-6.

[0229]

[0230] Preparation of dielectric elastomer (ex3-7, HX25) according to Experimental Example 3-7

[0231] In the above-described experimental example 1-2, 25 wt% of the barium titanate (BaTiO3) was added to the nanoparticle (4) to produce a dielectric elastomer (ex3-7, HX25) according to experimental example 3-7.

[0232]

[0233] Experimental Examples 3-1 to 3-7 described above can be summarized as shown in Table 4 below.

[0234] Classification Solvent (1) Nanoparticle (4) Content (wt%) Experiment Example 3-1 (ex3-1, HX5) Ethyl alcohol (EtOH) and hexane (HX)5 Experiment Example 3-2 (ex3-2, HX10) Ethyl alcohol (EtOH) and hexane (HX)10 Experiment Example 3-3 (ex3-3, HX15) Ethyl alcohol (EtOH) and hexane (HX)15 Experiment Example 3-4 (ex3-4, HX18) Ethyl alcohol (EtOH) and hexane (HX)18 Experiment Example 3-5 (ex3-5, HX20) Ethyl alcohol (EtOH) and hexane (HX)20 Experiment Example 3-6 (ex3-6, HX22) Ethyl alcohol (EtOH) and hexane (HX)22 Experiment Example 3-7 (ex3-7, HX25) Ethyl alcohol (EtOH) and Hexane (HX)25

[0235]

[0236] FIG. 14 is a graph showing the stress-strain of dielectric elastomers according to Experimental Examples 2-1 to 2-7 of the present application, and FIG. 15 is a graph showing the stress-strain of dielectric elastomers according to Experimental Examples 3-1 to 3-7 of the present application.

[0237] Referring to FIGS. 14 and FIGS. 15, it can be seen that as the content of the nanoparticles (4) increases, the strain decreases.

[0238] Thus, it can be proven that deformation stability is improved when the content of the nanoparticles (4) in the dielectric elastomer (100) is increased.

[0239]

[0240] Fabrication of a stretchable capacitor (ex2-1, DCM5) according to Experimental Example 2-1

[0241] 2.3 g of 2-methyl-4-pentanone (MIBK) was added to 1.6 g of a precursor mixed with Ecoflex A and B in a mass ratio of 1:1, and stirred for 30 minutes. Then, silver flakes were added and stirred for 2 hours to prepare the silver substrate source. After applying the silver substrate source to a thin film-shaped stainless steel mask using a screen printing method, the remaining solution was removed by heating at 90°C for 1 hour, and cured at 120°C for 1 hour to prepare a substrate (200) containing the silver flakes.

[0242] A flexible capacitor (ex2-1, DCM5) according to Experimental Example 2-1 was manufactured by placing a substrate (200) containing the silver flakes on both sides with the dielectric elastomer according to Experimental Example 2-1 described above in between.

[0243]

[0244] Fabrication of a stretchable capacitor (ex2-2, DCM10) according to Experimental Example 2-2

[0245] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-2 described above in between, and a flexible capacitor (ex2-2, DCM10) according to Experimental Example 2-2 was manufactured.

[0246]

[0247] Fabrication of a stretchable capacitor (ex2-3, DCM15) according to Experimental Example 2-3

[0248] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-3 described above in between, and a flexible capacitor (ex2-3, DCM15) according to Experimental Example 2-3 was manufactured.

[0249]

[0250] Fabrication of a stretchable capacitor (ex2-4, DCM18) according to Experimental Example 2-4

[0251] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-4 described above in between, and a flexible capacitor (ex2-4, DCM18) according to Experimental Example 2-4 was manufactured.

[0252]

[0253] Manufacture of a stretchable capacitor (ex2-5, DCM20) according to Experimental Example 2-5

[0254] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-5 described above in between, and a flexible capacitor (ex2-5, DCM20) according to Experimental Example 2-5 was manufactured.

[0255]

[0256] Fabrication of a stretchable capacitor (ex2-6, DCM22) according to Experimental Example 2-6

[0257] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-6 described above in between, and a flexible capacitor (ex2-6, DCM22) according to Experimental Example 2-6 was manufactured.

[0258]

[0259] Fabrication of a stretchable capacitor (ex2-7, DCM25) according to Experimental Example 2-7

[0260] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-7 described above in between, and a flexible capacitor (ex2-7, DCM25) according to Experimental Example 2-7 was manufactured.

[0261]

[0262] Fabrication of a stretchable capacitor (ex3-1, HX5) according to Experimental Example 3-1

[0263] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 3-1 described above in between, and a flexible capacitor (ex3-1, HX5) according to Experimental Example 3-1 was manufactured.

[0264]

[0265] Fabrication of a stretchable capacitor (ex3-2, HX10) according to Experimental Example 3-2

[0266] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 3-2 described above in between, and a flexible capacitor (ex3-2, HX10) according to Experimental Example 3-2 was manufactured.

[0267]

[0268] Fabrication of a stretchable capacitor (ex3-3, HX15) according to Experimental Example 3-3

[0269] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 3-3 described above in between, and a flexible capacitor (ex3-3, HX15) according to Experimental Example 3-3 was manufactured.

[0270]

[0271] Fabrication of a stretchable capacitor (ex3-4, HX 18) according to Experimental Example 3-4

[0272] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 3-4 described above in between, and a flexible capacitor (ex3-4, HX 18) according to Experimental Example 3-4 was manufactured.

[0273]

[0274] Fabrication of a stretchable capacitor (ex3-5, HX20) according to Experimental Example 3-5

[0275] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 2-5 described above in between, thereby manufacturing a flexible capacitor (ex3-5, HX20) according to Experimental Example 3-5.

[0276]

[0277] Fabrication of a stretchable capacitor (ex3-6, HX22) according to Experimental Example 3-6

[0278] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 3-6 described above in between, and a flexible capacitor (ex3-6, HX22) according to Experimental Example 3-6 was manufactured.

[0279]

[0280] Fabrication of a stretchable capacitor (ex3-7, HX25) according to Experimental Example 3-7

[0281] In the capacitor manufacturing method according to Experimental Example 2-1 described above, a substrate (200) containing the silver flakes was placed on both sides with the dielectric elastomer according to Experimental Example 3-7 described above in between, and a flexible capacitor (ex3-7, HX25) according to Experimental Example 3-7 was manufactured.

[0282]

[0283] FIG. 16 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 2-1 to 2-7 of the present application, and FIG. 17 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 3-1 to 3-7 of the present application.

[0284] Referring to FIG. 16, it can be seen that when the co-solvent (1) contains ethyl alcohol (EtOH) and dichloromethane (DCM), the change in capacitance of the capacitor (ex2-4, DCM18) according to Experimental Example 2-4, in which the content of the nanoparticle (4) is 18 wt%, is the smallest.

[0285] Thus, the critical significance of the above experiment Example 2-4 (ex2-4, DCM18) can be understood.

[0286] Additionally, referring to FIG. 16, it can be seen that when the co-solvent (1) contains ethyl alcohol (EtOH) and hexane (HX), the change in capacitance of the capacitor (ex3-5, HX20) according to Experimental Example 3-5, in which the content of the nanoparticle (4) is 20 wt%, is the smallest.

[0287] Thus, the critical significance of the above experimental example 3-5 (ex3-5, HX20) can be understood.

[0288]

[0289] FIG. 18 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 2-4 to 2-6 of the present application, FIG. 19 is a graph showing the change in capacitance of a flexible capacitor according to Experimental Examples 3-4 to 3-6 of the present application, FIG. 20 is a graph showing the measurement of the gauge factor (GF) of a flexible capacitor according to Experimental Examples 2-1 to 2-7 of the present application, FIG. 21 is a graph showing the measurement of the gauge factor (GF) of a flexible capacitor according to Experimental Examples 3-1 to 3-7 of the present application, and FIG. 22 is a graph summarizing the gauge factor (GF) of a flexible capacitor according to Experimental Examples 2-1 to 2-7 and Experimental Examples 3-1 to 3-7 of the present application.

[0290] Referring to FIG. 18, when the co-solvent (1) includes ethyl alcohol (EtOH) and dichloromethane (DCM), it can be seen that the capacitor according to Experimental Example 2-5 (ex2-5, DCM20), in which the nanoparticle (4) content is 20 wt%, and the capacitor according to Experimental Example 2-6 (ex2-6, DCM22), in which the nanoparticle (4) content is 22 wt%, have a gauge factor (GF) of 0.

[0291] Additionally, referring to FIG. 19, when the co-solvent (1) contains ethyl alcohol (EtOH) and hexane (HX), the capacitor (ex3-5, HX20) according to Experimental Example 3-5, in which the nanoparticle (4) content is 20 wt%, can be seen to have a gauge factor (GF) of 0.

[0292] Thus, in the case of the above experimental example 2-5 (ex2-5, DCM20), the above experimental example 2-6 (ex2-6, DCM22), and the above experimental example 3-5 (ex3-5, HX20), it can be proven that the manufactured flexible capacitor (1000) has a gauge factor (GF) of 0.

[0293] Referring to FIG. 20, it can be seen that when the co-solvent (1) contains ethyl alcohol (EtOH) and dichloromethane (DCM), the gauge factor (GF) of the capacitor (ex2-4, DCM18) according to Experimental Example 2-4, in which the content of the nanoparticle (4) is 18 wt%, is the smallest.

[0294] Thus, the critical significance of the above experiment Example 2-4 (ex2-4, DCM18) can be understood.

[0295] Additionally, referring to FIG. 21, it can be seen that when the co-solvent (1) contains ethyl alcohol (EtOH) and hexane (HX), the change in capacitance of the capacitor (ex3-5, HX20) according to Experimental Example 3-5, in which the content of the nanoparticle (4) is 20 wt%, is the smallest.

[0296] Thus, the critical significance of the above experimental example 3-5 (ex3-5, HX20) can be understood.

[0297] Referring to FIG. 22, it can be seen that when the co-solvent (1) is not included (ecoflex), the gauge factor (GF) of the manufactured capacitor is the largest, when the co-solvent (1) includes ethanol and hexane (hexane / ethanol), the gauge factor (GF) is relatively small, and when the co-solvent (1) includes ethanol and dichloromethane (DCM) (DCM / ethanol), the gauge factor (GF) is the smallest.

[0298]

[0299] Fabrication of a stretchable capacitor (ex2-4, DCM-18-E) according to Experimental Example 2-4

[0300] A substrate (200) containing the copper pattern was manufactured by irradiating a 17 μm copper foil with an ultraviolet laser.

[0301] A flexible capacitor (ex2-4, DCM-18-E) according to Experimental Example 2-4 was manufactured by placing a substrate (200) including the copper pattern between a dielectric elastomer according to Experimental Example 2-4 described above.

[0302]

[0303] Fabrication of a stretchable capacitor (ex2-5, DCM-20-E) according to Experimental Example 2-5

[0304] In the capacitor manufacturing method according to Experimental Example 2-4 described above, a substrate (200) including the copper pattern was placed between a dielectric elastomer according to Experimental Example 2-5 described above, and a flexible capacitor (ex2-5, DCM-20-E) according to Experimental Example 2-5 was manufactured.

[0305]

[0306] Fabrication of a stretchable capacitor (ex2-6, DCM-22-E) according to Experimental Example 2-6

[0307] In the capacitor manufacturing method according to Experimental Example 2-4 described above, a substrate (200) including the copper pattern was placed between a dielectric elastomer according to Experimental Example 2-6 described above, and a flexible capacitor (ex2-6, DCM-22-E) according to Experimental Example 2-6 was manufactured.

[0308]

[0309] Fabrication of a stretchable capacitor (ex3-4, HX-18-E) according to Experimental Example 3-4

[0310] In the capacitor manufacturing method according to Experimental Example 2-4 described above, a substrate (200) including the copper pattern was placed between the dielectric elastomer according to Experimental Example 3-4 described above, and a flexible capacitor (ex3-4, HX-18-E) according to Experimental Example 3-4 was manufactured.

[0311]

[0312] Fabrication of a stretchable capacitor (ex3-5, HX-20-E) according to Experimental Example 3-5

[0313] In the capacitor manufacturing method according to Experimental Example 2-4 described above, a substrate (200) including the copper pattern was placed between a dielectric elastomer according to Experimental Example 3-5 described above, and a flexible capacitor (ex3-5, HX-20-E) according to Experimental Example 3-5 was manufactured.

[0314]

[0315] Fabrication of a stretchable capacitor (ex3-6, HX-22-E) according to Experimental Example 3-6

[0316] In the capacitor manufacturing method according to Experimental Example 2-4 described above, a substrate (200) including the copper pattern was placed between a dielectric elastomer according to Experimental Example 3-6 described above, and a flexible capacitor (ex3-6, HX-22-E) according to Experimental Example 3-6 was manufactured.

[0317]

[0318] FIG. 23 is a graph showing the change in resistance of a flexible capacitor according to Experimental Examples 2-4 to 2-6 and Experimental Examples 3-4 to 3-6 of the present application.

[0319] Referring to FIG. 23, it can be seen that according to Experimental Examples 2-4 to 2-6 (ex2-4, DCM-18-E to ex2-6, DCM-22-E) and Experimental Examples 3-4 to 3-6 (ex3-4, HX-18-E to ex3-6, HX-22-E), the serpentine electrode containing the copper pattern has a smaller change in resistance than the stretchable silver flake containing the silver flake.

[0320]

[0321] Figure 24 is a graph showing the change in capacitance of a flexible capacitor according to a general flexible substrate.

[0322] Referring to FIG. 24, it can be seen that the change in capacitance of a flexible capacitor (serpentine electrode) including the copper pattern according to a general flexible substrate is linear.

[0323]

[0324] FIG. 25 is a graph showing the gauge factor (GF) of a stretchable capacitor according to Experimental Examples 2-4 to 2-6 and Experimental Examples 3-4 to 3-6 of the present application.

[0325] Referring to FIG. 25, it can be seen that the flexible capacitor (serpentine electrode) including the copper pattern according to Experimental Examples 2-4 to 2-6 (ex2-4, DCM-18-E to ex2-6, DCM-22-E) and Experimental Examples 3-4 to 3-6 (ex3-4, HX-18-E to ex3-6, HX-22-E) has a gauge factor (GF) greater than -0.5 and less than or equal to 0.

[0326] In particular, according to the above experimental examples 2-5, 2-6 (ex2-5, ex2-6, DCM-20-E, DCM-22-E) and the above experimental examples 3-4, 3-5 (ex3-4, ex3-5, HX-18-E, HX-20-E), it can be confirmed that the flexible capacitor (serpentine electrode) including the copper pattern has a gauge factor (GF) of 0.

[0327] Thus, in the case of the above experimental examples 2-5, 2-6 (ex2-5, ex2-6, DCM-20-E, DCM-22-E) and the above experimental examples 3-4, 3-5 (ex3-4, ex3-5, HX-18-E, HX-20-E), it can be proven that the manufactured flexible capacitor (1000) has a gauge factor (GF) of 0.

[0328]

[0329] FIG. 26 is a graph showing the change in capacitance over 100 cycles of a flexible capacitor according to Experimental Example 3-5 of the present application.

[0330] Referring to Fig. 26, it can be seen that the stretchable capacitor (serpentine electrode) containing the copper pattern according to Experimental Example 3-5 (ex3-5, HX-20-E) maintains a stable capacitance for 100 cycles under a 30% stretched state.

[0331]

[0332] FIG. 27 is a graph showing the change in capacitance measured according to the movement of the body when the elastic capacitor according to Experimental Example 3-5 of the present application is worn on the knee, and FIG. 28 is a graph showing the change in capacitance measured according to the movement of the body when the elastic capacitor according to Experimental Example 3-5 of the present application is worn on the arm.

[0333] Referring to FIGS. 27 and 28, it can be seen that the flexible capacitor (ex3-5, HX-20-E, our capacitor) according to Experimental Example 3-5 showed no substantial change in capacitance during physical movements corresponding to non-stretching and non-pressurization of the capacitor (1000), namely standing, and physical movements corresponding to stretching of the capacitor (1000), namely walking and exercising, while the capacitance changed during physical movements corresponding to pressure of the capacitor (1000), namely falling.

[0334] Thus, it can be demonstrated that the flexible capacitor (1000, our capacitor) according to the embodiment of the present application can distinguish between stretching and pressure, and that when stretched, the capacitance is maintained, and when pressurized, the capacitance is increased.

[0335] On the other hand, referring to FIGS. 27 and 28, in the case of a general capacitor, there was substantially no change in capacitance during body movements corresponding to non-extension and non-pressurization of the capacitor, i.e., standing; however, it can be seen that the capacitance changed during body movements corresponding to extension of the capacitor, i.e., walking and exercising, and body movements corresponding to pressure of the capacitor (1000), i.e., falling.

[0336] Therefore, it can be seen that, unlike the embodiment of the present application, a general capacitor cannot distinguish between expansion and pressure.

[0337]

[0338] FIG. 29 is a graph showing the signal measured by applying a flexible capacitor and a conventional capacitor according to Experimental Example 3-5 of the present application to a differentiator, FIG. 30 is a graph showing the signal measured by applying a flexible capacitor and a conventional capacitor according to Experimental Example 3-5 of the present application to an integrator, and FIG. 31 is a graph showing the signal measured by applying a flexible capacitor and a conventional capacitor according to Experimental Example 3-5 of the present application to an RC circuit (resistor-capacitor circuit, RC circuit).

[0339] FIGS. 29(a), FIGS. 30(a), and FIGS. 31(a) are signal measurement graphs of a general capacitor, FIGS. 29(b), FIGS. 30(b), and FIGS. 31(b) are signal measurement graphs of a flexible capacitor (ex3-5, HX-20-E, our capacitor) according to Experimental Example 3-5, and FIGS. 29(c), FIGS. 30(c), and FIGS. 31(c) are signal comparison measurement graphs of a general capacitor and a flexible capacitor (ex3-5, HX-20-E, our capacitor) according to Experimental Example 3-5.

[0340] Referring to FIGS. 29 to 31, it can be seen that the flexible capacitor according to Experimental Example 3-5 (ex3-5, HX-20-E, our capacitor) maintains a constant capacitance despite mechanical deformation.

[0341] On the other hand, in the case of a general capacitor, it can be seen that mechanical deformation increases capacitance, lowering the resonant frequency and degrading circuit performance.

[0342] Thus, the capacitance stability of the flexible capacitor (1000, our capacitor) according to the embodiment of the present application can be demonstrated.

[0343]

[0344] Although the present application has been described in detail using preferred embodiments, the scope of the present application is not limited to specific embodiments and should be interpreted by the appended claims. Furthermore, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the present application.

Claims

1. A step of preparing a co-solvent; A step of preparing a base source by mixing the above co-solvent and a polymer precursor; A step of preparing a dielectric elastomer source by mixing the above base source and nanoparticles; and The method comprises the step of coating and curing the dielectric elastomer source on a support to produce a dielectric elastomer in which a polymer formed from the polymer precursor surrounds the nanoparticles. The adjacent nanoparticles include forming a cluster, A method for manufacturing a dielectric elastomer, wherein the above cosolvent comprises ethyl alcohol (EtOH) and hexane (HX), and the above nanoparticles are provided with barium titanate (BaTiO3) in an amount greater than 18 wt% and less than 22 wt%.

2. In Paragraph 1, The above common medium is, Includes a dispersed solution and a non-dispersed solution, A method for manufacturing a dielectric elastomer comprising forming the above nanoparticles into the above cluster.

3. In Paragraph 1, A method for manufacturing a dielectric elastomer, wherein the above polymer precursor includes an Ecoflex precursor.

4. Step of preparing a co-solvent; A step of preparing a base source by mixing the above co-solvent and a polymer precursor; A step of preparing a dielectric elastomer source by mixing the above base source and nanoparticles; and The method comprises the step of coating and curing the dielectric elastomer source on a support to produce a dielectric elastomer in which a polymer formed from the polymer precursor surrounds the nanoparticles. The adjacent nanoparticles include forming a cluster, A method for manufacturing a dielectric elastomer, wherein the above cosolvent comprises ethyl alcohol (EtOH) and dichloromethane (DCM), and the above nanoparticles are provided with barium titanate (BaTiO3) in an amount greater than 15 wt% and less than 20 wt%.

5. In Paragraph 1, The step of washing the support before the coating is further included, The above washing step is, A step of boiling the above support in a solution; and A method for manufacturing a dielectric elastomer comprising the step of ultrasonically treating the boiled support.

6. In Paragraph 5, The step of surface treating the support before the coating is further included, The above surface treatment step is, A method for manufacturing a dielectric elastomer comprising surface treating the washed support with a release agent.

7. Step of preparing a co-solvent; A step of preparing a base source by mixing the above co-solvent and a polymer precursor; A step of preparing a dielectric elastomer source by mixing the above base source and nanoparticles; and The method comprises the step of coating and curing the dielectric elastomer source on a support to produce a dielectric elastomer in which a polymer formed from the polymer precursor surrounds the nanoparticles. The adjacent nanoparticles include forming a cluster, The above coating includes performing the process for more than 20 seconds and less than 1 minute in a rotational atmosphere of more than 250 rpm and less than 1000 rpm, and A method for manufacturing a dielectric elastomer, comprising performing the curing at a temperature greater than 50°C and less than 100°C for a duration greater than 30 minutes and less than 2 hours.

8. In Paragraph 7, A method for manufacturing a dielectric elastomer, comprising one cycle of the coating and curing, wherein the cycle is repeated multiple times.

9. In Paragraph 1, A method for manufacturing a dielectric elastomer, wherein the step of manufacturing the above dielectric elastomer source includes further mixing of a surfactant.

10. Nanoparticles; and A polymer surrounding the above nanoparticles, comprising The adjacent nanoparticles include forming a cluster, A dielectric elastomer comprising a capacitance that is maintained during expansion, increases during pressurization, and has a Gauge Factor (GF) of 0.

11. In Paragraph 10, In the case of the above expansion, the cluster is deformed into a T-shape while maintaining capacitance, and A dielectric elastomer comprising, when the above-mentioned pressure is applied, a decrease in thickness and an increase in capacitance.

12. Step of preparing a co-solvent; A step of preparing a base source by mixing the above co-solvent and a polymer precursor; A step of preparing a dielectric elastomer source by mixing the above base source and nanoparticles; A step of manufacturing a dielectric elastomer comprising a cluster formed from adjacent nanoparticles by coating and curing the dielectric elastomer source on a support; A step of detaching the dielectric elastic body from the above support; and The method includes the step of manufacturing a flexible capacitor by placing substrates on both sides with the above-mentioned dielectric elastomer in between, A method for manufacturing a flexible capacitor, wherein the capacitance is maintained during stretching, the capacitance increases during pressurization, and the Gauge Factor (GF) is 0.

13. In Paragraph 12, The above substrate is, A method for manufacturing a flexible capacitor comprising silver flakes or patterned copper.

14. A dielectric elastomer comprising nanoparticles and a polymer surrounding the nanoparticles; and It includes substrates disposed on both sides with the above-mentioned dielectric elastic element in between, In the above dielectric elastomer, adjacent nanoparticles form a cluster, and When expanded, the capacitance is maintained, and When pressurized, the capacitance increases, and A flexible capacitor including one with a Gauge Factor (GF) of 0.

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