JP7089979B2 - Actuator - Google Patents

Description

The present invention relates to an actuator.

Dielectric elastomer actuators are being studied as one of the devices that convert electrical inputs into mechanical outputs. Such an actuator has a structure in which an elastomer layer is sandwiched by a pair of electrode layers, and when a voltage is applied to the electrodes, the actuator expands and contracts in the direction in which the elastomer layer expands. In such a dielectric elastomer actuator, the Coulomb force generated between the electrodes is one of the driving principles.

For example, Patent Document 1 discloses an actuator in which a dielectric elastomer is sandwiched between a pair of electrodes. In this document, in order to improve the dielectric breakdown strength and the displacement amount of the actuator, an attempt is made to pre-stretch a dielectric elastomer in a two-dimensional direction and hold it with an electrode.

Special Table 2003-505865 Gazette

One of the problems according to the present invention is to provide an actuator having a large displacement amount that sufficiently brings out the deformation performance of the dielectric elastomer.

The present invention has been made to solve at least a part of the above-mentioned problems, and can be realized as the following aspects or application examples.

One aspect of the actuator according to the present invention is
It includes an intermediate layer and a first drive layer and a second drive layer arranged so as to face each other with the intermediate layer interposed therebetween.
The first drive layer and the second drive layer include a first electrode, a dielectric elastomer layer stretched in the first direction, and a second electrode, respectively.
The intermediate layer contains a restraining member and contains a restraining member.
The restraining member includes a first adhesive portion that adheres to the first drive layer and a second adhesive portion that adheres to the second drive layer.
The first adhesive portions adjacent to each other in the first direction are arranged at a distance of a first distance from each other.
The second adhesive portions adjacent to each other in the first direction are arranged at a distance of a second distance from each other.
The restraining member limits the first spacing and the second spacing from narrowing in the first direction due to the restoring force of the dielectric elastomer layer.

One aspect of the actuator according to the present invention is
It includes an intermediate layer, a drive layer arranged so as to face each other across the intermediate layer, and an elastomer layer stretched in a first direction.
The drive layer includes a first electrode, a dielectric elastomer layer and a second electrode.
The intermediate layer contains a restraining member and contains a restraining member.
The restraining member includes a first adhesive portion that adheres to the drive layer and a second adhesive portion that adheres to the elastomer layer.
The first adhesive portions adjacent to each other in the first direction are arranged at a distance of a first distance from each other.
The second adhesive portions adjacent to each other in the first direction are arranged at a distance of a second distance from each other.
The restraining member limits the first spacing and the second spacing from narrowing in the first direction due to the restoring force of the elastomer layer.

In the actuator according to the present invention
The first adhesive portion is on a straight line along a second direction orthogonal to the first direction.
The second adhesive portion may be on a straight line along the second direction.

In the actuator according to the present invention
The restraining member includes a plurality of rod members extending in a second direction orthogonal to the first direction.
The outer shape of the cross section of the rod member perpendicular to the second direction is circular, and the outer shape is circular.
Adjacent rod members are arranged in the first direction in a state of being in contact with each other.
The first adhesive portion and the second adhesive portion may be a part of the outer peripheral surface of the rod member, respectively.

In the actuator according to the present invention
The restraining member includes a connecting portion extending in the first direction and a connecting portion.
A plurality of first support portions extending from the connecting portion in a third direction orthogonal to the first direction and the second direction orthogonal to the first direction to form the first adhesive portion.
A plurality of second support portions extending from the connecting portion in the third direction to form the second adhesive portion,
May include.

The actuator according to the present invention can be greatly displaced by utilizing the deformation of the dielectric elastomer and the restoring force of the elastomer.

The perspective view which shows typically an example of the actuator which concerns on 1st Embodiment. The schematic diagram of the vertical cross section of the example of the actuator which concerns on 1st Embodiment. The perspective view which shows typically the operation of the example of the actuator which concerns on 1st Embodiment. The schematic diagram of the vertical cross section which shows the operation of the example of the actuator which concerns on 1st Embodiment. The schematic diagram of the vertical cross section of an example of an actuator having a deformation example suppressing member. The schematic diagram of the vertical cross section of an example of an actuator having a deformation example suppressing member. The schematic diagram of the vertical cross section of an example of an actuator having a deformation example suppressing member. The schematic diagram of the vertical cross section of the example of the actuator which concerns on 2nd Embodiment. The graph which shows the example of the SS curve of the dielectric elastomer.

Hereinafter, some embodiments of the present invention will be described. The embodiments described below describe an example of the present invention. The present invention is not limited to the following embodiments, and includes various modifications implemented without changing the gist of the present invention. Not all of the configurations described below are essential configurations of the present invention.

1. 1. First Embodiment 1.1. Structure of Actuator FIG. 1 is a perspective view schematically showing an actuator 100 according to the present embodiment. FIG. 2 is a schematic view of a vertical cross section of the actuator 100 according to the present embodiment.

The actuator 100 of the present embodiment includes an intermediate layer 30 and a first drive layer 10 and a second drive layer 20 arranged so as to face each other with the intermediate layer 30 interposed therebetween. As shown in FIGS. 1 and 2, in the actuator 100 according to the present embodiment, the intermediate layer 30 is sandwiched by the two drive layers of the first drive layer 10 and the second drive layer 20, and the first drive layer is sandwiched. 10. The intermediate layer 30 and the second drive layer 20 are laminated in this order.

1.1.1. First Drive Layer The first drive layer 10 includes a first electrode 2, a dielectric elastomer layer 4, and a second electrode 6. The first electrode 2, the dielectric elastomer layer 4 and the second electrode 6 are sequentially laminated, and the dielectric elastomer layer 4 is arranged between the first electrode 2 and the second electrode 6.

The first electrode 2 is one electrode that is paired with the second electrode 6 and applies a voltage (electric field) to the dielectric elastomer layer 4. The first electrode 2 is not limited in shape, material, electrical resistance, etc., as long as it can exert a function of applying a voltage and can follow the deformation of the dielectric elastomer layer 4. The shape of the first electrode 2 is, for example, a flat plate shape, a film shape, a coating film shape, or the like. The first electrode 2 may have one or more holes, and for example, a slit or the like may be formed when viewed in a plane. Further, for example, the first electrode 2 may have a shape such as a comb shape or a mesh when viewed in a plane.

The region of the dielectric elastomer layer 4 narrowed by the first electrode 2 together with the second electrode 6 may be the entire dielectric elastomer layer 4 or a part of the dielectric elastomer layer 4. The first electrode 2 and the dielectric elastomer layer 4 may be in direct contact with each other, or may be in contact with each other via another layer such as an adhesive layer.

The material of the first electrode 2 is a material having conductivity, for example, a metal such as aluminum, copper, or gold, an alloy of various metals, carbon, a conductive oxide, a conductive polymer, a conductive paste, or the like. It can be exemplified.

Further, it is more preferable that the first electrode 2 is made of a material that can follow the deformation of the dielectric elastomer layer 4. Further, by adopting, for example, a conductive polymer, carbon paste, silver paste, or the like as the material of the first electrode 2, the dielectric elastomer layer 4 can be easily deformed by following the deformation.

The thickness of the first electrode 2 depends on the material, but for example, in the case of a conductive coating film, it is 1 μm or more and 500 μm or less, preferably 5 μm or more and 300 μm or less, and more preferably 10 μm or more and 200 μm or less. be.

The second electrode 6 is the other electrode paired with the first electrode 2 to apply a voltage (electric field) to the dielectric elastomer layer 4. The second electrode 6 is not limited in shape, material, etc., as long as it can exert a function of applying a voltage and can follow the deformation of the dielectric elastomer layer 4. The shape of the second electrode 6 is the same as that of the first electrode 2 described above. Further, the region of the dielectric elastomer layer 4 held by the second electrode 6 together with the first electrode 2, the material and the thickness of the second electrode 6 are the same as those of the first electrode 2.

The dielectric elastomer layer 4 is sandwiched between the first electrode 2 and the second electrode 6. When a voltage is applied to the first electrode 2 and the second electrode 6, the dielectric elastomer layer 4 is compressed in the thickness direction by attracting the first electrode 2 and the second electrode 6 by Coulomb force. As a result, the first drive layer 10 can be extended in a direction orthogonal to the thickness direction of the dielectric elastomer layer 4. In the present embodiment, the thickness direction is the direction along the z-axis.

The dielectric elastomer layer 4 is sandwiched between the first electrode 2 and the second electrode 6 in a state of being stretched in the first direction in advance. Alternatively, the dielectric elastomer layer 4 is laminated with the first electrode 2 and the second electrode 6 to form the first drive layer 10 before being stretched, and then the first drive layer 10 is stretched in the first direction. It is narrowly held by the 1 electrode 2 and the 2nd electrode 6. In any of these cases, when the actuator 100 is formed, the dielectric elastomer layer 4 is fixed to the intermediate layer 30 in a state of being previously stretched in the first direction. Since the first drive layer 10 is in a state where the dielectric elastomer layer 4 is stretched in the first direction, it has a restoring force that tends to shrink in the first direction.

Here, the "first direction" is a direction orthogonal to the thickness direction of the dielectric elastomer layer 4. Further, the first direction is a direction along the boundary surface of the dielectric elastomer layer 4 with the first electrode 2 or the second electrode 6. In this embodiment, the first direction is a positive or negative direction along the x-axis.

The dielectric elastomer layer 4 is a member of the actuator 100 in a state of being stretched in the first direction, but is in a direction intersecting the first direction (with the first electrode 2 or the second electrode 6 of the dielectric elastomer layer 4). It may be in a state of being stretched in the direction along the boundary surface). For example, the dielectric elastomer layer 4 may be stretched in a second direction orthogonal to the first direction.

Here, the "second direction" is a direction along the boundary surface of the dielectric elastomer layer 4 with the first electrode 2 or the second electrode 6, and is a direction orthogonal to the first direction. In this embodiment, the second direction is a positive or negative direction along the y-axis.

The dielectric elastomer layer 4 constitutes the actuator 100 in a stretched state, but the stretching may be uniaxial or multiaxial stretching, and the restoring force to be contracted may include a component in the first direction. ..

By fixing the first drive layer 10 to the intermediate layer 30 in a state where the dielectric elastomer layer 4 is stretched, the thickness of the dielectric elastomer layer 4 is reduced, and an electric field is applied to the first electrode 2 and the second electrode 6. The Coulomb force generated when applied can be made larger. Therefore, the deformation in the first direction can be made larger than that in the case of not stretching. Further, since the dielectric elastomer layer 4 is stretched and fixed to the intermediate layer 30, it becomes easy to utilize the operation in the stretched region where the Young's modulus of the dielectric elastomer layer 4 is low and it is easy to bend, and the quick response in the operation of the actuator 100 becomes easy. And it becomes easy to obtain a large deformation due to a small power.

If the stretch ratio of the dielectric elastomer layer 4 is too low, the restoring force due to rubber elasticity during operation of the actuator 100 is low, so that the amount of deformation is reduced. If the stretch ratio of the dielectric elastomer layer 4 is too high, the actuator 100 operates. Since it sometimes operates in a region close to the breaking elongation, there is a risk of breaking during operation. Therefore, it is preferable to set an appropriate stretching ratio according to the material and thickness to be used.

The thickness of the dielectric elastomer layer 4 is 10 μm or more and 1 mm or less, preferably 10 μm or more and 800 μm or less, more preferably 50 μm or more and 500 μm or less, and further preferably 100 μm or more and 500 μm or less. If the thickness of the dielectric elastomer layer 4 is too thin, the dielectric elastomer layer 4 may be easily torn in the assembly process of the actuator 100. Further, if the thickness of the dielectric elastomer layer 4 is too thick, the elasticity of the dielectric elastomer layer 4 becomes large, and biaxial stretching may be difficult. Further, since the distance between the electrodes during the operation of the actuator 100 becomes large, the responsiveness to the applied voltage tends to decrease.

The material of the dielectric elastomer layer 4 is not particularly limited as long as it has insulating properties and rubber elasticity, and is, for example, natural rubber, isoprene rubber, and styrene-butadiene rubber (SB).
R), nitrile rubber (NBR), ethylene / propylene / diene rubber (EPDM), acrylic rubber, silicone rubber, urethane rubber, acrylic elastomer and the like can be mentioned. Among these, as the material used for the dielectric elastomer layer 4, silicone rubber, urethane rubber, acrylic elastomer and the like are more suitable.

Further, as the material used for the dielectric elastomer layer 4, a material having low rigidity and high elongation is preferable. Specifically, as the mechanical properties of the material used for the dielectric elastomer layer 4, the modulus at 600% elongation in the tensile test based on JIS K6251 is 0.03 MPa or more and 1.0 MPa or less, preferably 0.03 MPa or more and 0. Further suitable materials are 5 MPa or less, more preferably 0.05 MPa or more and 0.3 MPa or less, and a breaking elongation of 800% or more, preferably 1000% or more.

Since the dielectric elastomer layer 4 is in a state of being stretched in the first direction, the first driving layer 10 has a restoring force that tends to shrink in the first direction. That is, when the actuator 100 is formed, the first drive layer 10 is always in a state of returning to its original shape due to rubber elasticity. In the actuator 100 of the present embodiment, the first drive layer 10 having a restoring force that tends to contract in the first direction is fixed to the intermediate layer 30, and is restored on both sides of the intermediate layer 30 together with the second drive layer 20 described later. It is fixed so that the stretched state is maintained in a state where the forces are balanced.

11.2. Second Drive Layer The second drive layer 20 is arranged so as to face the first drive layer 10 with the intermediate layer 30 interposed therebetween. In the present embodiment, the second drive layer 20 includes the first electrode 2, the dielectric elastomer layer 4, and the second electrode 6 as in the first drive layer 10. The shapes, functions, materials, physical properties, etc. of the first electrode 2, the dielectric elastomer layer 4, and the second electrode 6 are the same as those of the first drive layer 10 described above.

Also in the second drive layer 20, the thickness of the dielectric elastomer layer 4 is reduced by stretching the dielectric elastomer layer 4, and Coulomb generated when an electric field is applied to the first electrode 2 and the second electrode 6. The force can be increased. Therefore, the second drive layer 20 can be deformed more in the first direction as compared with the case where it is not stretched. Further, by stretching the dielectric elastomer layer 4, it becomes easy to utilize the operation in the stretched region where the Young's modulus of the dielectric elastomer layer 4 is low and it is easy to bend, and it becomes easy to obtain a quick response and a large deformation due to a small electric power.

When the actuator 100 is configured, the second drive layer 20 is in a state of being stretched in the first direction as in the case of the first drive layer 10 described above, so that the restoring force that tends to contract in the first direction is exerted. Have. That is, when the actuator 100 is configured, the second drive layer 20 is also in a state of always trying to return to its original shape due to rubber elasticity. The second drive layer 20 having a restoring force that tends to contract in the first direction is fixed to the intermediate layer 30, and the first drive layer 10 is restored on both sides of the intermediate layer 30 together with the above-mentioned first drive layer 10. The force and the restoring force of the second drive layer 20 are fixed so as to be maintained in a stretched state in a balanced state.

In the actuator 100, as shown in FIG. 1, the second electrode 6 of the first drive layer 10 is arranged on the intermediate layer 30 side, and the first electrode 2 of the second drive layer 20 is on the intermediate layer 30 side. Have been placed. However, any of the first electrode 2 and the second electrode 6 of the first drive layer 10 and the second drive layer 20 may be arranged on the intermediate layer 30 side.

11.3. Intermediate layer The intermediate layer 30 includes a restraining member 36. The restraining member 36 has a first adhesive portion 32 that adheres to the first drive layer 10 and a second adhesive portion 34 that adheres to the second drive layer 20.

The first adhesive portion 32 is a portion that adheres to the first drive layer 10 of the restraining member 36. A plurality of first adhesive portions 32 are provided. Further, the first adhesive portion 32 may be adhered to the second electrode 6 of the first drive layer 10. For example, when a hole is present in the second electrode 6, the dielectric elastomer layer is formed inside the hole. It may be adhered to 4.

In the first adhesive portion 32, the first adhesive portions 32 adjacent to each other in the first direction are arranged so as to be separated from each other by the first interval P1. In the illustrated example, the plurality of first spacing P1s are equal to each other, but depending on the shape of the restraining member 36, all of the plurality of first spacings P1 may be the same or different from each other.

The first adhesive portion 32 is arranged so as to be on a straight line along a second direction intersecting the first direction on the surface on which the intermediate layer 30 develops. Each drive layer and the restraining member 36 may be continuously bonded or discontinuously bonded along the second direction. In the examples of FIGS. 1 and 2, the first adhesive portion 32 is formed linearly along the second direction (y) orthogonal to the first direction (x).

The second adhesive portion 34 is a portion that adheres to the second drive layer 20 of the restraining member 36. The number of the second adhesive portions 34 and the mode of adhesion with the second drive layer 20 are the same as those of the first adhesive portions 32. The second adhesive portion 34 is formed on a straight line along the second direction (y) orthogonal to the first direction (x) like the first adhesive portion 32.

In the second adhesive portion 34, the second adhesive portions 34 adjacent to each other in the first direction are arranged so as to be separated from each other by the second interval P2. In the illustrated example, the first interval P1 and the second interval P2 are equal. Further, although the plurality of second intervals P2 existing in the drawing are equal to each other, the plurality of second intervals P2 may be the same or different from each other.

An adhesive can be used for the first adhesive portion 32 and the second adhesive portion 34. It is preferable to select an adhesive having a high compatibility with the material of the electrode layer and the dielectric elastomer layer 4. For example, when the restraining member 36 is adhered to the dielectric elastomer layer 4, and the dielectric elastomer layer 4 is made of silicone rubber, it is preferable to use a silicone-based adhesive. Further, when the electrode layer contains an adhesive component in the conductive paste, the suppressing member 36 can be adhered to the electrode layer by the conductive paste without using an adhesive.

The restraining member 36 limits the first spacing P1 and the second spacing P2 from being narrowed in the first direction by the restoring force of the dielectric elastomer layer 4 (first driving layer 10 and second driving layer 20). When a voltage is applied to the first electrode 2 and the second electrode 6 and either the first drive layer 10 or the second drive layer 20 operates, the interval between the first interval P1 and the second interval P2 Is allowed to narrow.

In the examples of FIGS. 1 and 2, the restraining member 36 includes a plurality of rod members 42 extending in a second direction orthogonal to the first direction, and the outer shape of the cross section of the rod member 42 perpendicular to the second direction is circular. The adjacent rod members 42 are arranged in the first direction in a state of being in contact with each other, and the first adhesive portion 32 and the second adhesive portion 34 are each a part of the outer peripheral surface of the rod member 42. Further, in the illustrated example, the first adhesive portion 32 and the second adhesive portion 34 are located at positions facing each other with the central axis of the rod member 42 interposed therebetween.

It is preferable that the bonding area (area of each bonded portion) between the suppressing member 36 and the electrode layer and / or the dielectric elastomer layer 4 is smaller. As the area of the bonded portion increases, it becomes easier to restrain the elongation deformation of the dielectric elastomer layer 4 in the first direction, and the displacement amount of the actuator tends to decrease.

Further, in the illustrated example, the rod member 42 has a hollow cylindrical shape, but may be a solid cylindrical shape. Further, the adjacent rod members 42 are in contact with each other without being adhered to each other. If the adjacent rod members 42 are in contact with each other, it is possible to limit the first interval P1 and the second interval P2 from being narrowed in the first direction by the restoring force of the first drive layer 10 and the second drive layer 20. Further, since the adjacent rod members 42 are not adhered to each other, the actuator 100 can be more easily deformed. That is, since the adjacent rod members 42 are not adhered to each other, the structure is such that the adjacent rod members 42 can easily change their relative positions while rotating.

As the material of the rod member 42, a metal, ceramics, a resin material, or the like can be applied. In particular, since the adjacent rod members 42 are not adhered to each other and are in contact with each other, a material having high crystallinity, a low coefficient of friction and a high Young's modulus is preferable. Examples of such materials include engineering plastic materials such as polyetheretherketone and polyimide. Further, between the rod member 42 and the first drive layer 10 and the second drive layer 20 (a portion of the intermediate layer 30 other than the restraining member 36), an elastic body that does not suppress the deformation of the intermediate layer 30 in the thickness direction. May be satisfied. As the elastic body, natural rubber, isoprene rubber, styrene-butadiene rubber (SBR), nitrile rubber (NBR), ethylene / propylene / diene rubber (EPDM), acrylic rubber, silicone rubber, urethane rubber and other rubbers, styrene-based, olefins. / Flexible materials such as alkene-based, vinyl chloride-based, urethane-based, amide-based thermoplastic resins, and foams thereof can be used.

In the present embodiment, an example in which the intermediate layer 30 is sandwiched by the two drive layers of the first drive layer 10 and the second drive layer 20 has been described, but the present invention is not limited to this, and the drive layer and the intermediate layer 30 are not limited to this. Another layer may be provided between the layers, or a part of the intermediate layer 30 may enter into the driving layer.

1.2. Actuator Operation FIG. 3 is a perspective view schematically showing the operation of the actuator 100 of the present embodiment. FIG. 4 is a schematic view of a vertical cross section when the actuator 100 according to the present embodiment operates.

In the examples of FIGS. 3 and 4, a voltage is applied between the first electrode 2 and the second electrode 6 of the first drive layer 10 of the actuator 100 of the present embodiment, and a Coulomb force is generated between the two electrodes. Is shown. When a voltage is applied between the first electrode 2 and the second electrode 6 of the first drive layer 10, the first drive layer 10 is stretched in the first direction.

When the first drive layer 10 extends in the first direction, the actuator 100 undergoes bending deformation due to the elongation of the first drive layer 10 and bending deformation due to the restoring force of the second drive layer 20. That is, in the actuator 100 of the present embodiment, the balance between the restoring force of the first drive layer 10 and the restoring force of the second drive layer 20 is lost due to the elongation of the first drive layer 10, and it is based on the bending deformation and the restoring force based on the elongation. Bending deformation is caused by two mechanisms of bending deformation. By stretching the dielectric elastomer layer 4 in the first direction in this way and using it, the displacement amount of the actuator 100 can be made very large.

The bending deformation when the first drive layer 10 of the actuator 100 extends in the first direction is such that the direction toward the plus side of the x-axis bends toward the plus side of the z-axis. In the illustrated example, the first drive layer 10 exists on the minus side of the z-axis, and the extension of the first drive layer 10 causes the second drive layer 20 to bend inward. That is, the actuator 100 deployed in the xy plane bends in the direction (thickness direction) along the z-axis. At this time, the rod member 42 moves along the outer circumference of the adjacent rod member 42. In the present embodiment, the thickness direction of the dielectric elastomer layer 4 may be referred to as a third direction, and the third direction is a positive or negative direction along the z-axis orthogonal to the x-axis and the y-axis.

Further, the actuator 100 hardly or at all bends so that the direction toward the plus side of the y-axis is the direction toward the plus side of the z-axis. This is because the rod member 42 extends in the second direction and restrains the deformation of the first drive layer 10 and the second drive layer 20 in the second direction.

If potentials having different polarities are applied to the first electrode 2 and the second electrode 6 of the first drive layer 10, the first drive layer 10 can be extended in the first direction. Further, either the first electrode 2 or the second electrode 6 may be used as the ground potential. Such a potential can be applied, for example, by a known voltage generator (battery, voltage application circuit, etc.).

A mechanical model of the rod member 42 in the bending structure of the actuator 100 of the present embodiment will be described with reference to FIGS. 2 and 4. In the state of FIG. 2, the first drive layer 10 and the second drive layer 20 are not driven, and the rod member 42 is in contact with the adjacent rod member 42. As a result, the first interval P1 and the second interval P2 are kept constant by the rod member 42. Further, in the state of FIG. 2, the restoring forces of the dielectric elastomer layers 4 in the first drive layer 10 and the second drive layer 20 are balanced in the first direction, and the actuator 100 does not bend and has a flat shape. ..

Here, when a voltage is applied to the first electrode 2 and the second electrode 6 of the first drive layer 10, the state shown in FIG. 4 is obtained. In the state of FIG. 4, the first drive layer 10 extends in the first direction, and each of the first intervals P1 expands. Further, in the state of FIG. 2, the second drive layer 20, which is balanced with the restoring force of the first drive layer 10 in the first direction, contracts due to its own restoring force, so that each of the second intervals P2 is narrowed. Further, at this time, the adjacent rod members 42 move while being in contact with each other, so that bending deformation occurs with the second drive layer 20 inside as shown in the figure.

Further, as shown in FIG. 4, since the rod member 42 has a cylindrical shape, the distance G between the central axes of the adjacent rod members 42 is always constant even in a bent state. At this time, the deformation of the first drive layer 10 in the second direction is constrained by the rod member 42 bonded via the first bonding portion 32.

Further, although not shown, when a voltage is applied between the first electrode 2 and the second electrode 6 of the second drive layer 20 of the actuator 100 and a Coulomb force is generated between the two electrodes, the bending is opposite. Works like this.

1.3. Variation of Drive Layer In the actuator 100 of the present embodiment, the first drive layer 10 and the second drive layer 20 are a set of three layers, that is, the first electrode 2, the dielectric elastomer layer 4, and the second electrode 6, respectively. The set is composed of a single layer, and the dielectric elastomer layers 4 are arranged one by one. However, the first drive layer 10 and the second drive layer 20 may both have two or more dielectric elastomer layers 4.

For example, in the embodiment in which the first driving layer 10 has two dielectric elastomer layers 4, the first electrode 2, the dielectric elastomer layer 4, the second electrode 6, the dielectric elastomer layer 4 and the first electrode 2 are laminated in this order. It may be a structure. Further, for example, as an embodiment in which the first driving layer 10 has two dielectric elastomer layers 4, the first electrode 2, the dielectric elastomer layer 4, the second electrode 6, the insulating layer, the first electrode 2, the dielectric elastomer layer 4 and the first electrode 2 are used. The structure may be one in which one electrode 2 is laminated in this order. By doing so, it may be possible to increase the deforming force of the first drive layer 10. The second drive layer 20 can have the same configuration. In such a case, the electrode layers are configured to exist on both sides of the dielectric elastomer layer 4, and voltages having different polarities are alternately applied to the electrode layers on both sides of one dielectric elastomer layer 4. Driven by.

Further, the first drive layer 10 and the second drive layer 20 do not have to be the same in terms of the thickness of each layer, the number of layers, and the like. For example, the number of dielectric elastomer layers 4 may be different on both sides as long as the restoring forces due to the rubber elasticity of the first drive layer 10 and the second drive layer 20 are balanced on both sides of the intermediate layer 30.

1.4. Variation of restraining member The restraining member 36 has a first adhesive portion 32 and a second adhesive portion 34, and the first interval P1 and the second interval P2 are narrowed in the first direction by the restoring force of the dielectric elastomer layer 4. Any form can be used as long as it can be restricted and bending in the thickness direction can be tolerated.

5, 6 and 7 are schematic cross-sectional views of a vertical cross section of an actuator having a modified example suppressing member 36. In the actuator 101 shown in FIG. 5, the restraining member 36 extends from the connecting portion 43 extending in the first direction and the connecting portion 43 in a third direction orthogonal to the first direction and the second direction orthogonal to the first direction. It is composed of a plurality of first support portions 44 forming the first adhesive portion 32, and a plurality of second support portions 45 extending from the connecting portion 43 in the third direction to form the second adhesive portion 34. There is. Further, the connecting portion 43, the first support portion 44 and the second support portion 45 are integrally formed.

In the actuator 101, in order not to interfere with the operation of the actuator 101, the distance between the plurality of first support portions 44 arranged in the first direction (first interval P1) is set to the first direction of the first support portion 44. It is more preferable to arrange them at intervals wider than the width. Also in the second support portion 45, the spacing between the plurality of second support portions 45 arranged in the first direction (second spacing P2) is arranged at a wider spacing than the width of the second support portion 45 in the first direction. Is more preferable.

Further, in the actuator 101, the first support portion 44 and the second support portion 45 suppress the contraction of the first drive layer 10 and the second drive layer 20 in the second direction. Further, the connecting portion 43 has a function of preventing the first interval P1 and the second interval P2 from being narrowed when the first drive layer 10 and the second drive layer 20 are not driven.

One of the advantages of the structure of the restraining member 36 of the actuator 101 is that the first adhesive portion 32 and the second adhesive portion 34, which are the adhesive portions between the intermediate layer 30 and each drive layer, are in surface contact rather than point contact. It is easy to secure an adhesive area, and it is easy to adjust the dimensions and spacing of the first support portion 44 and the second support portion 45. This makes it easy to adjust the deformation form of the first drive layer 10 and the second drive layer 20.

Further, the function of the connecting portion 43 is to prevent the first interval P1 and the second interval P2 from being narrowed, but the z-axis direction (first) to the extent that the actuator 101 does not interfere with the bending operation. It is preferable to have flexibility in the direction (direction orthogonal to the direction and the second direction). That is, as the material of the connecting portion 43, a material having a Young's modulus (flexural rigidity) lower than that of the dielectric elastomer layer 4 is suitable.

Materials for the connecting portion 43, the first support portion 44, and the second support portion 45 include general-purpose plastics such as polyethylene, polypropylene, polyvinyl chloride, and poly (meth) acrylic acid, and engineering such as polycarbonate, polyether ether ketone, and polyimide. Examples include plastic.

In the example of the actuator 101, the first support portion 44 and the second support portion 45 are arranged symmetrically with respect to the connecting portion 43, but the present invention is not limited to this, and the first support portion 44 and the second support portion are not limited to this. 45 may be arranged so as to be offset (for example, in a staggered pattern) across the connecting portion 43 in a cross-sectional view.

In the actuator 102 having the restraining member 36 of the modified example shown in FIG. 6, the restraining member 36 forms a connecting portion 43 extending in the first direction and a first adhesive portion 32 extending in the third direction from the connecting portion 43. It is composed of a plurality of first bellows members 46 and a plurality of second bellows members 47 extending from the connecting portion 43 in a third direction to form a second adhesive portion 34. Further, the connecting portion 43, the first bellows member 46 and the second bellows member 47 are integrally formed.

In the actuator 102, the first bellows member 46 and the second bellows member 47 suppress the contraction of the first drive layer 10 and the second drive layer 20 in the second direction. Further, the connecting portion 43 has a function of preventing the first interval P1 and the second interval P2 from being narrowed when the first drive layer 10 and the second drive layer 20 are not driven.

Further, in the actuator 102, the first drive layer 10 and the second drive layer 20 are adhered to the apex portions of the first bellows member 46 and the second bellows member 47 to form the first adhesive portion 32 and the second adhesive portion 34. However, the apex of the first bellows member 46 and the second bellows member 47 may be smoothed or flattened to increase the bonding area. The same applies to the bonded portion between the connecting portion 43 and the first bellows member 46 and the second bellows member 47.

One of the advantages of the structure of the restraining member 36 of the actuator 102 is that the connecting portion 43, which can be a stress concentration point in the structure of the restraining member 36 of the actuator 101, and the adhesive end portion of the first support portion 44 and the second support portion 45 are provided. , The structure is solved by the first bellows member 46 and the second bellows member 47.

Examples of the material of the first bellows member 46 and the second bellows member 47 include general-purpose plastics such as polyethylene, polypropylene, polyvinyl chloride and poly (meth) acrylic acid, and engineering plastics such as polycarbonate, polyether ether ketone and polyimide. can do.

In the actuator 103 having the restraining member 36 of the modified example shown in FIG. 7, the restraining member 36 includes a plurality of cylindrical members 48 having an annular cross section orthogonal to the second direction, and the adjacent cylindrical members 48 are separated from each other. The adjacent cylindrical members 48 are connected and configured by an annular ring member 49 that is arranged side by side in the first direction in the state and penetrates the inside of each of the adjacent cylindrical members 48. In the actuator 103, the ring members 49 interfere with each other (contact) to prevent the first interval P1 and the second interval P2 from being narrowed.

In the actuator 103, the cylindrical member 48 suppresses the contraction of the first drive layer 10 and the second drive layer 20 in the second direction. Further, the ring member 49 prevents the first interval P1 and the second interval P2 from being narrowed when the first drive layer 10 and the second drive layer 20 are not driven. Metal, ceramics, resin materials and the like can be applied to the material of the cylindrical member 48, and general-purpose plastic, engineering plastic and the like can be applied to the material of the ring member 49.

One of the advantages of the structure of the restraining member 36 of the actuator 103 is that the cylindrical members 48 having a hollow in advance can be fixed in a state of being connected by the ring member 49, so that the first interval P1 and the second interval P1 and the second interval in the assembly process can be fixed. The point that the deviation of P2 can be reduced can be mentioned.

1.5. Actuator Manufacturing Method As an example of the actuator manufacturing method of the present embodiment, the above-mentioned actuator 100 manufacturing method will be described.

First, the dielectric elastomer layer 4 is placed on a jig capable of simultaneously stretching two axes, and is simultaneously stretched in the first direction and the second direction. Next, the first electrode 2 and the second electrode 6 are assembled to the dielectric elastomer layer 4. The method of assembling the first electrode 2 and the second electrode 6 differs depending on the shape thereof, but the common point is that the dielectric elastomer layer 4 is assembled in a pre-stretched state. When the restraining member 36 and the dielectric elastomer layer 4 are directly adhered to each other, the dielectric elastomer layer 4 may be masked in advance and the first electrode 2 and the second electrode 6 may be assembled. The first electrode 2 and the second electrode 6 may be formed by applying carbon or may be formed by a method such as thin film deposition.

The restraining member 36 is assembled by providing a frame on the outside and fixing the restraining member 36 so as not to move. After that, an adhesive is applied to the portions to be bonded to the first electrode 2, the second electrode 6, and the dielectric elastomer layer 4, and the first electrode 2 and the second electrode 6 are bonded to the dielectric elastomer layer 4 in a stretched state. And glue. Depending on the type of adhesive used, it may be treated with heat, light or the like after being bonded to the dielectric elastomer layer 4.

For example, the actuator 100 described above can be manufactured by the above steps.

2. 2. Second Embodiment The actuator 100 of the first embodiment described above has two drive layers, but the actuator 100 may have one drive layer. That is, the actuator 200 according to the present embodiment includes an intermediate layer 30, a drive layer 10 arranged so as to face each other across the intermediate layer 30, and an elastomer layer 50 stretched in the first direction.

FIG. 8 is a schematic view showing a vertical cross section of the actuator 200 according to the present embodiment. The intermediate layer 30 and the drive layer 10 of the actuator 200 of the present embodiment are the same as the intermediate layer 30 and the first drive layer 10 described in the first embodiment, respectively, and the same reference numerals are given and detailed description thereof will be omitted. do. However, in the actuator 200, in the drive layer 10, the dielectric elastomer layer 4 may or may not be stretched in the first direction.

The actuator 200 has an elastomer layer 50. The elastomer layer 50 is arranged so as to be laminated on the drive layer 10 via the intermediate layer 30. Since the elastomer layer 50 is in a state of being stretched in the first direction in the actuator 200, it has a restoring force that tends to shrink in the first direction.

The elastomer layer 50 is fixed to the intermediate layer 30 in a state of being previously stretched in the first direction. Also in this embodiment, the first direction is a direction orthogonal to the thickness direction of the elastomer layer 50, and is a direction in which the restraining members 36 of the intermediate layer 30 are lined up.

The elastomer layer 50 is a member of the actuator 200 in a state of being stretched in the first direction, but may be in a state of being stretched in a direction intersecting the first direction. For example, the elastomer layer 50 may be stretched in a second direction orthogonal to the first direction. Here, the second direction is the "y" direction in the figure. In other words, the elastomer layer 50 constitutes the actuator 200 in a stretched state, but the stretching may be uniaxial or multiaxial stretching, as long as the stretching direction contains a component in the first direction. good.

The material of the elastomer layer 50 is not particularly limited as long as it has insulating properties and rubber elasticity, and is, for example, natural rubber, isoprene rubber, styrene-butadiene rubber (SBR), nitrile rubber (NBR), and ethylene. -Ethylene diene rubber (EPDM), acrylic rubber, silicone rubber, urethane rubber, acrylic elastomer and the like can be mentioned.

The actuator 200 has a first drive layer 10 on only one side with respect to the intermediate layer 30. Therefore, the actuator 200 operates so as to bend with the elastomer layer 50 as the inside.

In the actuator 200, the dielectric elastomer layer 4 may not be stretched. In that case, the composite of the intermediate layer 30 and the first driving layer 10 may have a high bending rigidity to the extent that it can withstand the restoring force of the elastomer layer 50. By doing so, the planar shape can be maintained even when the actuator 200 is not driven. Although not shown, the actuator 200 may be bent with the elastomer layer 50 inside in a non-driven state.

As the material of the elastomer layer 50, the same material as that of the dielectric elastomer layer 4 may be applied, or a different material may be applied. Specific examples thereof include materials showing rubber elasticity that are industrially used. For example, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, acrylonitrile budadien rubber, epichlorohydrin rubber, chloroprene rubber, butyl rubber, ethylene / propylene / diene rubber, silicone rubber, urethane rubber and the like can be mentioned.

The stretch ratio of the elastomer layer 50 is appropriately set in the same manner as the stretch ratio of the dielectric elastomer layer 4.

In the actuator 200, the dielectric elastomer layer 4 may be previously stretched only in, for example, the first direction. In the case of the previously stretched dielectric elastomer layer 4, the restoring force of the elastomer layer 50 and the restoring force of the drive layer 10 sandwich the intermediate layer 30 as in the actuator 100 of the first embodiment described above. If it is set to be balanced, the planar shape can be maintained. In this case, not only a material having a high anisotropy of Young's modulus in the thickness direction and the first direction but also a material having an isotropic Young's modulus can be used for the restraining member 36.

3. 3. Experimental Examples Hereinafter, the present invention will be described in more detail by means of experimental examples, but the present invention is not limited to these experimental examples.

FIG. 9 shows an SS diagram (stress-strain curve) obtained by a tensile test of silicone rubbers A, B, and C, which are examples of dielectric elastomers. Silicone rubbers A, B and C are obtained by varying the amount of the cross-linking agent to adjust the cross-linking density. The tensile test was performed on a JIS No. 1 dumbbell at 23 ° C. ± 2 ° C. and a tensile speed of 0.5 mm / min in accordance with JIS K6251.

Silicone rubber A has a high modulus at the time of 100% stretching, and it is difficult to stretch it by two axes.

Silicone rubber B has a wide extension region showing appropriate modulus, and the amount of deformation during actuator operation is also good.

Since the modulus of the silicone rubber C in the low stretch region is too low, it is difficult to handle the silicone rubber C in the stretched state.

From these results, it was found that a material having a low Young's modulus and a high elongation is suitable as a material used for the dielectric elastomer layer used for the actuator. Specifically, as the material used for the dielectric elastomer layer, it was found that a material having a modulus in the range of 0.03 MPa or more and 1.0 MPa or less at 600% elongation and a breaking elongation of 800% or more is suitable. rice field.

Further, when the dielectric elastomer layer was previously stretched using the silicone rubber B, it was found that it is preferable to stretch the dielectric elastomer layer in the displacement region of 50% or more and 500% or less in FIG.

Further, when the draw ratio is less than 50%, it is considered that the amount of deformation is reduced because the restoring force due to the rubber elasticity during the operation of the actuator is lowered. On the other hand, if the stretching ratio exceeds 500%, the actuator operates in a region close to the breaking elongation, which is not preferable in terms of durability.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the present invention includes substantially the same configurations as those described in the embodiments (eg, configurations with the same function, method and result, or configurations with the same purpose and effect). The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. Further, the present invention includes a configuration having the same action and effect as the configuration described in the embodiment or a configuration capable of achieving the same object. Further, the present invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

2 ... 1st electrode, 4 ... Dielectric elastomer layer, 6 ... 2nd electrode, 10 ... 1st drive layer, 20 ... 2nd drive layer, 30 ... Intermediate layer, 32 ... 1st adhesive part, 34 ... 2nd adhesive part , 36 ... restraining member, 42 ... rod member, 43 ... connecting part, 44 ... first support part, 45 ... second support part, 46 ... first bellows member, 47 ... second bellows member, 48 ... cylindrical member, 49. ... Ring member, 50 ... Elastomer layer, 100, 101, 102, 103, 200 ... Actuator, P1 ... First interval, P2 ... Second interval, G ... Distance

Claims (5)

It includes an intermediate layer and a first drive layer and a second drive layer arranged so as to face each other with the intermediate layer interposed therebetween.
The first drive layer and the second drive layer include a first electrode, a dielectric elastomer layer stretched in the first direction, and a second electrode, respectively.
The intermediate layer contains a restraining member and contains a restraining member.
The restraining member includes a first adhesive portion that adheres to the first drive layer and a second adhesive portion that adheres to the second drive layer.
The first adhesive portions adjacent to each other in the first direction are arranged at a distance of a first distance from each other.
The second adhesive portions adjacent to each other in the first direction are arranged at a distance of a second distance from each other.
The restraining member is an actuator that limits the first interval and the second interval from being narrowed in the first direction by the restoring force of the dielectric elastomer layer. It includes an intermediate layer, a drive layer arranged so as to face each other across the intermediate layer, and an elastomer layer stretched in a first direction.
The drive layer includes a first electrode, a dielectric elastomer layer and a second electrode.
The intermediate layer contains a restraining member and contains a restraining member.
The restraining member includes a first adhesive portion that adheres to the drive layer and a second adhesive portion that adheres to the elastomer layer.
The first adhesive portions adjacent to each other in the first direction are arranged at a distance of a first distance from each other.
The second adhesive portions adjacent to each other in the first direction are arranged at a distance of a second distance from each other.
The restraining member is an actuator that limits the first interval and the second interval from being narrowed in the first direction by the restoring force of the elastomer layer. In claim 1 or 2,
The first adhesive portion is on a straight line along a second direction orthogonal to the first direction.
The second adhesive portion is an actuator on a straight line along the second direction. In any one of claims 1 to 3,
The restraining member includes a plurality of rod members extending in a second direction orthogonal to the first direction.
The outer shape of the cross section of the rod member perpendicular to the second direction is circular, and the outer shape is circular.
Adjacent rod members are arranged in the first direction in a state of being in contact with each other.
An actuator in which the first adhesive portion and the second adhesive portion are each a part of the outer peripheral surface of the rod member. In any one of claims 1 to 3,
The restraining member includes a connecting portion extending in the first direction and a connecting portion.
A plurality of first support portions extending from the connecting portion in a third direction orthogonal to the first direction and the second direction orthogonal to the first direction to form the first adhesive portion.
A plurality of second support portions extending from the connecting portion in the third direction to form the second adhesive portion,
Including actuators.

Images