Pressure sensor

Abstract

To provide a pressure sensor capable of detecting various different pressures.SOLUTION: A pressure sensor A10 includes: a dielectric elastomer layer 11; a first electrode layer 21 and a second electrode layer 22; a first support 31 and a second support 32; and an elastic member 41, the dielectric elastomer layer 11 being fixed to the first support 31 so as to extend outward from the outer edge of the first support 31 in a circumferential direction when viewed in a first direction z, the outer end of the dielectric elastomer layer 11 being fixed to the second support 32 when viewed in the first direction z, and the elastic member 41 being interposed between the first support 31 and the second support 32 in the first direction z.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pressure sensor. [Background technology]

[0002] Patent Document 1 discloses an example of a conventional sensor. The sensor disclosed in this document includes a dielectric elastomer layer and a pair of electrode layers. As the dielectric elastomer layer expands and contracts, the capacitance between the pair of electrode layers changes. By processing this change in capacitance, it is possible to detect the force applied to the dielectric elastomer layer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-032586 Summary of the Invention [Problem to be solved by the invention]

[0004] There are various types of force (pressure) that a sensor should detect, and the detectable force (pressure) is limited depending on the structure of the sensor, etc.

[0005] The present invention was conceived in light of the above circumstances, and an object of the present invention is to provide a pressure sensor that can detect a wider variety of pressures. [Means for solving the problem]

[0006] A pressure sensor provided by a first aspect of the present invention comprises a dielectric elastomer layer, a first electrode layer arranged on one side of the dielectric elastomer layer and a second electrode layer arranged on the other side, a first support and a second support, and an elastic member, wherein the dielectric elastomer layer is fixed to the first support so as to extend from the outer edge of the first support to the periphery when viewed in a first direction, and the outer end of the dielectric elastomer layer is fixed to the second support when viewed in the first direction, and the elastic member is interposed between the first support and the second support in the first direction.

[0007] In a preferred embodiment of the present invention, the elastic member is detachable.

[0008] In a preferred embodiment of the present invention, the elastic member has a solid shape and is made of resin.

[0009] In a preferred embodiment of the present invention, the dielectric elastomer layer has a portion interposed between the first support and the elastic member.

[0010] In a preferred embodiment of the present invention, the second electrode layer is arranged on the second support side relative to the first electrode layer in the first direction, and when viewed in the first direction, the second electrode layer extends from the outer edge of the first electrode layer.

[0011] A pressure sensor provided by a second aspect of the present invention comprises a dielectric elastomer body, and a first electrode layer and a second electrode layer arranged on opposite sides of the dielectric elastomer body in a first direction, and detects pressure changes in the first direction by changes in capacitance between the first electrode layer and the second electrode layer caused by dimensional changes in the dielectric elastomer body in the first direction.

[0012] In a preferred embodiment of the present invention, the dielectric elastomer body is in the form of a film.

[0013] In a preferred embodiment of the invention, the dielectric elastomer body is flat.

[0014] In a preferred embodiment of the present invention, the dielectric elastomer body is curved.

[0015] In a preferred embodiment of the present invention, the dielectric elastomer body has a thickness of 10 μm to 5 mm.

[0016] In a preferred embodiment of the present invention, the dielectric elastomer body has a cavity therein.

[0017] In a preferred embodiment of the present invention, the piezoelectric element further comprises a soft body that is arranged on the second electrode layer side in the first direction and has the same softness as the dielectric elastomer body or is softer than the dielectric elastomer body.

[0018] In a preferred embodiment of the present invention, the soft body has a hollow portion therein. [Effects of the Invention]

[0019] According to the present invention, a wider variety of pressures can be detected.

[0020] Other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a perspective view showing a pressure sensor according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a pressure sensor according to a first embodiment of the present invention. [Figure 3] 1 is a system configuration diagram showing a pressure sensor system using a pressure sensor according to a first embodiment of the present invention. [Figure 4] 1 is a cross-sectional view showing an example of use of the pressure sensor according to the first embodiment of the present invention. [Figure 5]1 is a plan view showing an example of use of a pressure sensor according to a first embodiment of the present invention. [Figure 6] FIG. 4 is a cross-sectional view showing another example of use of the pressure sensor according to the first embodiment of the present invention. [Figure 7] FIG. 4 is a cross-sectional view showing another example of use of the pressure sensor according to the first embodiment of the present invention. [Figure 8] FIG. 4 is a cross-sectional view showing another example of use of the pressure sensor according to the first embodiment of the present invention. [Figure 9] FIG. 4 is a cross-sectional view showing a first modified example of the pressure sensor according to the first embodiment of the present invention. [Figure 10] FIG. 4 is a cross-sectional view showing a pressure sensor according to a second embodiment of the present invention. [Figure 11] FIG. 10 is a cross-sectional view showing a first modified example of the pressure sensor according to the second embodiment of the present invention. [Figure 12] FIG. 10 is a cross-sectional view showing a second modified example of the pressure sensor according to the second embodiment of the present invention. [Figure 13] FIG. 10 is a cross-sectional view showing a third modified example of the pressure sensor according to the second embodiment of the present invention. [Figure 14] FIG. 10 is a cross-sectional view showing a fourth modified example of the pressure sensor according to the second embodiment of the present invention. [Figure 15] FIG. 10 is a cross-sectional view showing a pressure sensor according to a third embodiment of the present invention. [Figure 16] FIG. 10 is a cross-sectional view showing an example of use of a pressure sensor according to a third embodiment of the present invention. [Figure 17] FIG. 10 is a cross-sectional view showing an example of use of a pressure sensor according to a third embodiment of the present invention. [Figure 18] FIG. 10 is a cross-sectional view showing a pressure sensor according to a fourth embodiment of the present invention. [Figure 19] FIG. 10 is a cross-sectional view showing a first modified example of the pressure sensor according to the fourth embodiment of the present invention. [Figure 20] FIG. 10 is a cross-sectional view showing a second modified example of the pressure sensor according to the fourth embodiment of the present invention. [Figure 21] FIG. 10 is a cross-sectional view showing a pressure sensor according to a fifth embodiment of the present invention. [Figure 22]FIG. 10 is a cross-sectional view showing an example of use of a pressure sensor according to a fifth embodiment of the present invention. [Figure 23] FIG. 10 is a cross-sectional view showing an example of use of a pressure sensor according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

[0023] The terms "first," "second," etc. in this disclosure are used for identification purposes only and are not intended to impose any order on their objects.

[0024] First Embodiment 1 to 8 show a pressure sensor according to a first embodiment of the present invention. The pressure sensor A10 of this embodiment includes a dielectric elastomer layer 11, a first electrode layer 21, a second electrode layer 22, a first support 31, a second support 32, and an elastic member 41.

[0025] The dielectric elastomer layer 11 is required to be elastically deformable and to be an insulator. The material of the dielectric elastomer layer 11 is not particularly limited, but preferred examples include silicone elastomer, acrylic elastomer, urethane, HNBR (hydrogenated nitrile rubber), fluorine-based rubber, fluorosilicone, etc. The shape of the dielectric elastomer layer 11 is not limited in any way, and in the illustrated example, it is circular when viewed in the first direction z.

[0026] The first electrode layer 21 is disposed on the surface of the dielectric elastomer layer 11 on the z1 side in the first direction z. The second electrode layer 22 is disposed on the surface of the dielectric elastomer layer 11 on the z2 side in the first direction z. The first electrode layer 21 and the second electrode layer 22 are formed from a material that is conductive and can undergo elastic deformation to follow the elastic deformation of the dielectric elastomer layer 11. An example of such a material is a material in which a filler that imparts conductivity is mixed into an elastically deformable main material. A preferred example of the filler is carbon nanotubes.

[0027] The shapes of the first electrode layer 21 and the second electrode layer 22 are not limited in any way. In the illustrated example, the first electrode layer 21 and the second electrode layer 22 are annular when viewed in the first direction z. In addition, in the illustrated example, the second electrode layer 22 extends from the outer edge of the first electrode layer 21 when viewed in the first direction z. In this case, by adding a first annular member 321 (described later) to the side of the second electrode layer 22, a configuration can be realized in which the elastic member 41 can be more easily replaced.

[0028] The first support 31 and the second support 32 are members that appropriately support the dielectric elastomer layer 11, the first electrode layer 21, and the second electrode layer 22. There are no limitations on the material of the first support 31 and the second support 32, and they may be made of an insulating material such as a resin, for example.

[0029] The shape of the first support 31 is not limited in any way, and in the illustrated example, it is circular when viewed in the first direction z. The dielectric elastomer layer 11 is fixed to the first support 31 so as to extend from the outer edge of the first support 31 to the periphery when viewed in the first direction z. In the illustrated example, the dielectric elastomer layer 11 is fixed to the first support 31 without the first electrode layer 21 interposed therebetween.

[0030] The shape of the second support 32 is not limited in any way, and in the illustrated example, it has a circular ring shape when viewed in the first direction z. The outer edge of the dielectric elastomer layer 11 is fixed to the second support 32 when viewed in the first direction z.

[0031] The specific configuration of the second support 32 is not limited in any way, and in the illustrated example, it includes a first annular member 321, a second annular member 322, a first pad 325, and a second pad 326. The first annular member 321 and the second annular member 322 each have a circular ring shape when viewed in the first direction z. The dielectric elastomer layer 11 is fixed to the second support 32 by sandwiching the outer edge portion of the dielectric elastomer layer 11 between the first annular member 321 and the second annular member 322. The first annular member 321 and the second annular member 322 can be repeatedly fixed and released by appropriately using, for example, a threaded member such as a screw or a clamping member such as a clip.

[0032] The first pad 325 is made of a conductive material such as metal and is fixed to the first annular member 321. The first pad 325 is electrically connected to the first electrode layer 21. The second pad 326 is made of a conductive material such as metal and is fixed to the second annular member 322. The second pad 326 is electrically connected to the second electrode layer 22.

[0033] The elastic member 41 is interposed between the first support 31 and the second support 32 in the first direction z. The elastic member 41 has an elastic modulus sufficient to cause a change in capacitance between the first electrode layer 21 and the second electrode layer 22 when a pressure to be detected by the pressure sensor A10 is applied. The material of the elastic member 41 is not particularly limited, and examples thereof include rubber and resin. The elastic member 41 may also be made of a metal material and have a structure capable of significant elastic deformation. In the illustrated example, the elastic member 41 has a cylindrical or rectangular parallelepiped shape.

[0034] By interposing the elastic member 41 between the first support 31 and the second support 32, the dielectric elastomer layer 11 assumes, for example, a flat truncated cone shape in a predetermined stretched state.

[0035] 2, the first support 31 and the second support 32 move closer to each other. This changes the stretch state of the dielectric elastomer layer 11, and the distance between the first electrode layer 21 and the second electrode layer 22 changes. This changes the capacitance between the first electrode layer 21 and the second electrode layer 22. The degree of proximity between the first support 31 and the second support 32 when a predetermined pressure is applied can be adjusted in various ways depending on the size, shape, and material of the elastic member 41.

[0036] 4 and 5 show an example of use of the pressure sensor A10. In this example, multiple pressure sensors A10 are arranged in a structure 9. The structure 9 is, for example, an annular member having a flange 91 and a flange 92. Multiple pressure sensors A10 are arranged between the flange 91 and the flange 92. The flange 91 and the flange 92 are fixed to each other by a threaded member such as a screw. Furthermore, when a fluid is introduced into the structure 9, a sealant 93 may be arranged between the flange 91 and the flange 92. The multiple pressure sensors A10 detect the pressure generated between the flange 91 and the flange 92.

[0037] In the illustrated example, as shown in Fig. 2, the control unit 8 is connected to the first pad 325 and the second pad 326. The control unit 8 performs processing to detect the pressure applied to the pressure sensor A10 from the change in capacitance between the first electrode layer 21 and the second electrode layer 22. Fig. 3 shows an example of the control unit 8 in the usage example shown in Fig. 5.

[0038] The control unit 8 of this example includes a plurality of CV conversion units 81 , a plurality of amplifier units 82 , an A / D conversion unit 83 , a CPU 84 , and an I / O unit 85 .

[0039] The CV conversion unit 81 converts the capacitance change of the pressure sensor A10 into a voltage change. The amplifier unit 82 amplifies the voltage output from the CV conversion unit 81. In this example, the number of CV conversion units 81 and amplifier units 82 is, for example, the same as the number of pressure sensors A10. The A / D conversion unit 83 converts the analog signals output from the amplifier units 82 into digital signals and outputs them. The CPU 84 calculates, for example, the pressure at each pressure sensor A10 from the output signal of the A / D conversion unit 83. The I / O unit 85 is, for example, a USB terminal, and outputs the pressure value that is the processing result by the CPU 84 to, for example, a PC 89.

[0040] 6 to 8 show other examples of use of the pressure sensor A10. Fig. 6 shows a state in which the pressure sensor A10 equipped with the elastic member 41 is disassembled. Specifically, in the second support 32, the first annular member 321 and the second annular member 322 are released from fixation and are separated from each other in the first direction z. This makes it possible to remove the elastic member 41 from the outside.

[0041] 7, the elastic member 41 is removed, and another elastic member 42 is placed on the second annular member 322. The elastic member 42 has specifications different from those of the elastic member 41, and may be selected as appropriate from among elastic members 41 that are made of the same material but have different dimensions in the first direction z, or that have the same shape and size but are made of a different material, or that are different in all of size, dimensions, and material.

[0042] 8, the first annular member 321 and the second annular member 322 are fixed together again. This puts the pressure sensor A10, which has the elastic member 42 instead of the elastic member 41, in a state where it can detect pressure. Thereafter, pressure detection is performed in the manner described above.

[0043] Next, the operation of the pressure sensor A10 will be described.

[0044] According to this embodiment, when the pressure shown in FIG. 2 is applied, the elastic member 41 elastically deforms. This deforms the dielectric elastomer layer 11, changing the distance between the first electrode layer 21 and the second electrode layer 22. This changes the capacitance between the first electrode layer 21 and the second electrode layer 22. By processing this change in capacitance, the pressure applied to the pressure sensor A10 can be detected. The illustrated pressure does not directly stretch or contract the dielectric elastomer layer 11. For example, if the illustrated pressure were to directly stretch or contract the dielectric elastomer layer 11, the dielectric elastomer layer 11 would need to be positioned along the first direction z. The pressure sensor A10 can detect pressure in a direction nearly perpendicular to the dielectric elastomer layer 11. Therefore, a wider variety of pressures can be detected.

[0045] 4 and 5, it is possible to detect the pressure generated in the flanges 91 and 92 (structure 9) by arranging multiple pressure sensors A10 between the flanges 91 and 92. Because the pressure sensors A10 have a flat structure, they can be sandwiched between the flanges 91 and 92 together with, for example, a sealing material 93, which has the advantage of being easy to install.

[0046] 6 to 8, in pressure sensor A10, elastic members 41 and 42 are detachable. This allows the specifications of elastic members 41 and 42 to be appropriately determined depending on the magnitude of the pressure to be detected and the space in which pressure sensor A10 is installed, and makes it possible to detect pressure with a pressure sensor A10 having a more suitable configuration.

[0047] 9 to 23 show other embodiments of the present invention. In these figures, elements that are the same as or similar to those in the above embodiment are given the same reference numerals. Furthermore, the configurations of the various parts in each of the modified examples and each of the embodiments can be combined with each other as appropriate within the scope of not causing technical contradictions.

[0048] <First Modification of First Embodiment> 9 shows a first modified example of the pressure sensor A10. The pressure sensor A11 of this example includes an elastic member 43 instead of the above-described elastic members 41 and 42. The elastic member 43 has a different shape from the elastic members 41 and 42. The elastic member 43 has a shape in which the cross-sectional area of ​​the portion on the z1 side in the first direction z decreases toward the tip, and has, for example, a hemispherical portion.

[0049] This modification also makes it possible to detect a wider variety of pressures. As can be seen from this modification, the elastic member of the present invention can be made to have a variety of shapes.

[0050] Second Embodiment 10 shows a pressure sensor according to a second embodiment of the present invention. The pressure sensor A20 of this embodiment comprises a dielectric elastomer body 12, a first electrode layer 21 and a second electrode layer 22.

[0051] Like the dielectric elastomer layer 11, the dielectric elastomer body 12 is required to be elastically deformable and have high insulating strength. There are no particular limitations on the material of the dielectric elastomer body 12, but preferred examples include silicone elastomer, acrylic elastomer, urethane, HNBR (hydrogenated nitrile rubber), fluorine-based rubber, and fluorosilicone. Furthermore, the dielectric elastomer body 12 is thicker in the first direction z than the dielectric elastomer layer 11, and has a three-dimensional shape, so to speak. An example of the dimensions of the dielectric elastomer body 12 is that the thickness in the first direction z is 10 μm to 5 mm, for example.

[0052] The first electrode layer 21 is disposed on the surface of the dielectric elastomer body 12 on the z1 side in the first direction z. The second electrode layer 22 is disposed on the surface of the dielectric elastomer body 12 on the z2 side in the first direction z. Like the pressure sensor A10, the first electrode layer 21 and the second electrode layer 22 are preferably formed from a material that is conductive and capable of elastic deformation that can follow the elastic deformation of the dielectric elastomer body 12. Examples of such materials include a conductive polymer or a material in which a filler that imparts conductivity is mixed into an elastically deformable main material. A preferred example of the filler is carbon nanotubes.

[0053] Also in this embodiment, in order to perform pressure detection using the pressure sensor A20, for example, the above-described control unit 8 may be connected to the pressure sensor A20.

[0054] In the illustrated example, pressure members 51 and 52 are disposed on both sides of pressure sensor A20 in the first direction z. Pressure members 51 and 52 apply a pressure to be detected to pressure sensor A20 and are made of, for example, an insulating material. In the illustrated example, pressure members 51 and 52 have a flat shape extending in a direction perpendicular to the first direction z. Pressure members 51 and 52 may be configured with a conductive core material and an insulating layer provided on the surface of the core material. Alternatively, when first electrode layer 21 and second electrode layer 22 are made of a conductive material having sufficient rigidity (thickness) to function as pressure members 51 and 52, first electrode layer 21 and second electrode layer 22 may also serve as pressure members 51 and 52.

[0055] In this embodiment, when pressure is applied in the direction of the arrow shown in the figure, the pressure member 51 and the pressure member 52 move closer to each other. This reduces the thickness of the dielectric elastomer body 12 in the first direction z, causing a change in the capacitance between the first electrode layer 21 and the second electrode layer 22. The above-mentioned pressure can be detected by processing this capacitance change with the control unit 8. This pressure is different from a pressure that directly stretches the dielectric elastomer body 12 (for example, a force that pulls the dielectric elastomer body 12 to both sides in a direction perpendicular to the first direction z), and is a pressure in a direction that sandwiches the dielectric elastomer body 12. The pressure sensor A20 can detect such pressures and can detect a wider variety of pressures.

[0056] <First Modification of Second Embodiment> 11 shows a first modified example of pressure sensor A20. Pressure sensor A21 of this modified example differs from pressure sensor A20 in the shapes of pressure members 51 and 52, and correspondingly, the shapes of dielectric elastomer body 12, first electrode layer 21, and second electrode layer 22 also differ from those of pressure sensor A20.

[0057] The pressure member 52 of this modified example has a recessed shape toward the z2 side in the first direction z. The pressure member 51 has a protruding shape toward the z2 side in the first direction z. The dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 are sandwiched between the recess of the pressure member 52 and the protruding portion of the pressure member 51. Therefore, the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 have a curved shape toward the z2 side in the first direction z. The recess of the pressure member 52 is preferably large enough to accommodate all of the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22.

[0058] This modification also makes it possible to detect a wider variety of pressures. As can be seen from this modification, the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 are deformable depending on the shapes of the pressure members 51 and 52, so that a wide variety of pressures can be detected using pressure members 51 and 52 of various shapes.

[0059] <Second Modification of Second Embodiment> 12 shows a second modified example of the pressure sensor A20. The pressure sensor A22 of this modified example differs from the pressure sensors A20 and A21 in the shapes of the pressure members 51 and 52.

[0060] In this modified example, the pressure member 51 has inclined surfaces on both sides in a direction perpendicular to the first direction z. The pressure member 52 has inclined surfaces facing the inclined surfaces of the pressure member 51. The dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 are disposed between the inclined surfaces of the pressure member 51 and the inclined surfaces of the pressure member 52.

[0061] An example of a configuration in which the cross-sectional shape is as shown in the figure is a configuration in which the pressure member 51 is circular and has a flattened truncated cone shape when viewed in the first direction z, and the pressure member 52, the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 are ring-shaped when viewed in the first direction z. Alternatively, the cross-sectional shape shown in the figure may be uniformly continued in the direction perpendicular to the first direction z for the dielectric elastomer body 12, the first electrode layer 21, the second electrode layer 22, the pressure member 51, and the pressure member 52. In this case, two of each of the dielectric elastomer body 12, the first electrode layer 21, the second electrode layer 22, and the pressure member 52 are provided.

[0062] This modification also makes it possible to detect a wider variety of pressures. In addition, when two dielectric elastomer bodies 12, two first electrode layers 21, two second electrode layers 22, and two pressure members 52 are provided, it is possible to detect bias in the applied pressure in the left-right direction in the figure.

[0063] <Third Modification of Second Embodiment> 13 shows a third modified example of the pressure sensor A20. The pressure sensor A23 of this modified example has a configuration in which a pressure member 52 presses the dielectric elastomer body 12, the first electrode layer 21, and a part of the second electrode layer 22.

[0064] This modification also makes it possible to detect a wider variety of pressures. As can be seen from this modification, the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 may be configured to be pressed entirely or partially.

[0065] <Fourth Modification of Second Embodiment> 14 shows a fourth modification of the pressure sensor A20. In this modification, the thickness of the dielectric elastomer body 12 in the first direction z is non-uniform.

[0066] In this modified example, the dielectric elastomer body 12 is thickest at the center and becomes thinner toward the outer edge. When no pressure is applied, only the center portion of the first electrode layer 21 contacts the pressure member 51, and only the center portion of the second electrode layer 22 contacts the pressure member 52.

[0067] This modification also allows for a wider variety of pressures to be detected. The pressure sensor A24 may have the cross-sectional shape shown in the figure and be annular when viewed in the first direction z. In this case, the pressure sensor A24 can also serve as a sealing material, such as an O-ring. For example, by sandwiching the annular pressure sensor A24 between flanges 91 and 92 shown in FIG. 4, the sealing material 93 can be omitted. Furthermore, by dividing the first electrode layer 21 and the second electrode layer 22 into four parts in the circumferential direction, pressures at multiple locations in the circumferential direction can be measured individually. As can be seen from this modification, the thickness of the dielectric elastomer body 12 in the first direction z may be uniform or non-uniform.

[0068] <Third embodiment> 15 to 17 show a pressure sensor according to a third embodiment of the present invention. In the pressure sensor A30 of this embodiment, the dielectric elastomer body 12 has a cavity 121.

[0069] The cavity 121 is provided inside the dielectric elastomer body 12 and is filled with a gas such as air. The internal pressure of the cavity 121 is set appropriately. If the internal pressure of the cavity 121 is atmospheric pressure, when the pressure sensor A30 shown in FIG. 15 is placed in a normal atmospheric condition, no pressure is applied to move the first electrode layer 21 and the second electrode layer 22 closer to or farther apart.

[0070] 16 shows a state in which the atmospheric pressure in the environment in which the pressure sensor A30 is placed drops. In this case, the internal pressure of the cavity 121 becomes relatively high, causing the dielectric elastomer body 12 to expand and deform. This increases the distance between the first electrode layer 21 and the second electrode layer 22, reducing the capacitance.

[0071] 17 shows a state in which the air pressure in the environment in which the pressure sensor A30 is placed increases. In this case, the internal pressure of the cavity 121 becomes relatively low, causing the dielectric elastomer body 12 to shrink and deform. This reduces the distance between the first electrode layer 21 and the second electrode layer 22, increasing the capacitance.

[0072] This modification also makes it possible to detect a wider variety of pressures. Furthermore, since the dielectric elastomer body 12 has the cavity 121, it is possible to detect changes in the atmospheric pressure in the environment in which the pressure sensor A30 is placed.

[0073] <Fourth embodiment> 18 shows a fourth embodiment of the present invention. The pressure sensor A40 of this embodiment further includes a soft body 61 and a soft body 62.

[0074] The soft body 61 is disposed between the first electrode layer 21 and the pressure member 51. The soft body 62 is disposed between the second electrode layer 22 and the pressure member 52. The soft body 61 and the soft body 62 are both made of a material softer than the dielectric elastomer body 12. When using the hardness of JIS K 6253 Type E (Asker C of SRIS0101), for example, the softness of the dielectric elastomer body 12 is 5 to 80, and the soft body 61 and the soft body 62 is 0 to 20, preferably 1 to 15. Examples of materials for the soft body 61 and the soft body 62 that can achieve such softness include silicone elastomer, acrylic elastomer, urethane, HNBR (hydrogenated nitrile rubber), fluorine-based rubber, and fluorosilicone. The soft bodies 61 and 62 may be made of the same material as the dielectric elastomer body 12. The soft bodies 61 and 62 are preferably made of an insulating material.

[0075] This embodiment also makes it possible to detect a wider variety of pressures. Furthermore, by providing soft bodies 61 and 62, the pressure applied to pressure members 51 and 52 can be applied more uniformly to the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 as a whole.

[0076] <First Modification of Fourth Embodiment> 19 shows a first modified example of pressure sensor A40. Pressure sensor A41 of this modified example has soft body 62 but does not have soft body 61. This modified example also makes it possible to detect a wider variety of pressures. Furthermore, as can be seen from this modified example, the sensor is not limited to a configuration having both soft body 61 and soft body 62, and may have a configuration having either one of them.

[0077] <Second Modification of Fourth Embodiment> 20 shows a second modified example of the pressure sensor A40. In the pressure sensor A42 of this modified example, the thickness of the soft body 62 is not uniform.

[0078] The soft body 62 of this modification has a maximum thickness in the first direction z at the center and becomes thinner toward the outer edge. In addition, the dielectric elastomer body 12, the first electrode layer 21, and the second electrode layer 22 are curved along the shape of the upper surface of the soft body 62.

[0079] This modification also makes it possible to detect a wider variety of pressures. As can be seen from this modification, the thickness of the soft body 62 may be uniform or may be non-uniform. This also applies to the soft body 61.

[0080] Fifth Embodiment 21 to 23 show a pressure sensor according to a fifth embodiment of the present invention. The pressure sensor A50 of this embodiment includes a dielectric elastomer body 12, a first electrode layer 21, a second electrode layer 22, and a soft body 62. The soft body 62 has a cavity 621.

[0081] The cavity 621 is provided inside the soft body 62 and is filled with a gas such as air. The internal pressure of the cavity 621 is set appropriately. When the internal pressure of the cavity 621 is atmospheric pressure, the soft body 62 does not undergo significant deformation when the pressure sensor A50 shown in FIG. 21 is placed in normal atmospheric conditions. Therefore, the dielectric elastomer body 12 does not undergo significant deformation, and the capacitance between the first electrode layer 21 and the second electrode layer 22 does not change.

[0082] 22 shows a state in which the air pressure in the environment in which the pressure sensor A50 is placed has decreased. In this case, the internal pressure of the cavity 621 becomes relatively high, causing the soft body 62 to expand and deform. This causes the dielectric elastomer body 12 to stretch, reducing the distance between the first electrode layer 21 and the second electrode layer 22 and increasing the capacitance.

[0083] 23 shows a state in which the air pressure in the environment in which the pressure sensor A50 is placed increases. In this case, the internal pressure of the cavity 621 becomes relatively low, causing the soft body 62 to shrink and deform. This causes the dielectric elastomer body 12 to expand, reducing the distance between the first electrode layer 21 and the second electrode layer 22 and increasing the capacitance.

[0084] This embodiment also makes it possible to detect a wider variety of pressures. Furthermore, since the soft body 62 has the hollow portion 621, it is possible to detect changes in atmospheric pressure in the environment in which the pressure sensor A50 is placed. Furthermore, in either the state in which the atmospheric pressure of the environment is decreased as shown in FIG. 22 or the state in which the atmospheric pressure of the environment is increased as shown in FIG. 23, the capacitance between the first electrode layer 21 and the second electrode layer 22 increases, making it possible to detect the absolute value of the change in atmospheric pressure. For example, by combining the pressure sensor A50 with another sensor that can detect whether the atmospheric pressure of the environment is decreased (negative pressure state) or increased (positive pressure state), it is possible to detect the absolute values ​​of both positive and negative pressures.

[0085] The pressure sensor according to the present invention is not limited to the above-described embodiment, and the specific configuration of each part of the pressure sensor according to the present invention can be freely designed and modified in various ways. [Explanation of symbols]

[0086] 11: Dielectric elastomer layer 12: Dielectric elastomer body 21: First electrode layer 22: Second electrode layer 31: 1st support 32:Second support 41, 42, 43: Elastic member 51, 52: Pressure member 61,62: Soft body 8: Control section 81: CV conversion section 82: Amplifier section 83: A / D conversion section 84 :CPU 85: I / O section 9: Structure 91,92: Flange 93: Sealing material 121: Cavity 321: First annular member 322: Second annular member 325: First pad 326: Second pad 621: Cavity A1, A10, A11, A20, A21, A22, A23, A24, A30, A40, A41, A42, A50: Pressure sensors z: first direction

Claims

1. a dielectric elastomer layer; a first electrode layer disposed on one side of the dielectric elastomer layer and a second electrode layer disposed on the other side; a first support and a second support; an elastic member; the dielectric elastomer layer is fixed to the first support so as to extend from an outer edge of the first support to a periphery thereof when viewed in a first direction; an outer end of the dielectric elastomer layer is fixed to the second support when viewed in the first direction; A pressure sensor, wherein the elastic member is interposed between the first support and the second support in the first direction.

2. The pressure sensor according to claim 1 , wherein the elastic member is detachable.

3. 3. The pressure sensor according to claim 2, wherein the elastic member has a solid shape and is made of resin.

4. The pressure sensor according to claim 2 , wherein the dielectric elastomer layer has a portion interposed between the first support and the elastic member.

5. the second electrode layer is disposed on a side of the second support relative to the first electrode layer in the first direction, The pressure sensor according to claim 2 , wherein the second electrode layer extends from an outer edge of the first electrode layer when viewed in the first direction.

6. a dielectric elastomer body; a first electrode layer and a second electrode layer disposed on opposite sides of the dielectric elastomer body in a first direction; A pressure sensor that detects pressure changes in the first direction based on changes in capacitance between the first electrode layer and the second electrode layer caused by dimensional changes in the dielectric elastomer body in the first direction.

7. The pressure sensor of claim 6 , wherein the dielectric elastomer body is in the form of a film.

8. The pressure sensor of claim 7 , wherein the dielectric elastomer body is flat.

9. The pressure sensor of claim 7 , wherein the dielectric elastomer body is curved.

10. The pressure sensor according to claim 6, wherein the dielectric elastomer body has a thickness of 10 μm to 5 mm.

11. The pressure sensor of claim 10 , wherein the dielectric elastomer body has an internal cavity.

12. The pressure sensor according to claim 6 , further comprising a soft body arranged on the second electrode layer side in the first direction and having the same softness as the dielectric elastomer body or softer than the dielectric elastomer body.

13. The pressure sensor according to claim 12 , wherein the soft body has a cavity therein.

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