JP2013243805A - Electrostatic actuator and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of easily manufacturing an electrostatic actuator having a large area.SOLUTION: An actuator includes: a plurality of first structures formed by crossing and knitting a first electrode group and a second electrode group to which voltages having opposite polarity to each other are applied, the electrode group including a plurality of belt-like electrodes arranged in parallel at predetermined intervals on the same plane; and a plurality of second structures formed by crossing the first electrode group and the second electrode group and knitting them in an overlapping state different from that of the first structure. The first structure and the second structure are alternately laminated so that the crossing positions between the first electrode group and the second electrode group match with each other in the first structure and the second structure. At the crossing positions of the first structure and the second structure adjacent to each other, the pair of belt-like electrodes adjacent to each other and facing each other are bonded at the crossing position when the applied voltages have the same polarity.

Description

  The present invention relates to an electrostatic actuator and a manufacturing method thereof.

  Since the electrostatic actuator can obtain a large driving force while being lightweight, it is expected to replace a motor using a magnetic force.

  As an example of the electrostatic actuator, Patent Document 1 discloses a stacked electrostatic actuator having a configuration in which a large number of electrodes are stacked and expanded or contracted according to a voltage applied between the electrodes.

JP 2007-259663 A

  However, in the prior art, in order to increase the electrode plate area, it is necessary to arrange many stacked electrostatic actuators in parallel. However, it takes time and cost to manufacture a large number of stacked electrostatic actuators.

  In view of the problems of the above-described conventional technology, an object of the present invention is to provide a technology capable of easily manufacturing a large-area electrostatic actuator.

  In order to solve the above problems, one aspect of the electrostatic actuator illustrating the present invention is an electrode group consisting of a plurality of strip electrodes arranged in parallel at a predetermined interval on the same plane and having opposite polarities to each other. A plurality of first structures formed by crossing and knitting the first electrode group and the second electrode group to which a voltage is applied, the first electrode group and the second electrode group are crossed, And a plurality of second structures formed by knitting in an overlapping state different from the first electrode surface, and the first structure and the second structure are the first structure and the second structure. The first electrode group and the second electrode group in the structure are alternately stacked so that the crossing positions of the first electrode group and the second electrode group coincide with each other, and at the crossing positions in the adjacent first structure body and second structure body, A pair of adjacent strip electrodes facing each other when the applied voltage has the same polarity. It is engaged.

  Further, the first structure body and the second structure body may be formed by plain weave.

  The strip electrode may be covered with a dielectric.

  In addition, the dielectric may cover the strip electrode thicker at the intersection position than at the intersection position.

  One aspect of a method for manufacturing an electrostatic actuator illustrating the present invention is to form a plurality of strip electrodes sandwiched between dielectrics having a predetermined thickness, and use a part of the plurality of strip electrodes as a first electrode group. The first electrode group is arranged in parallel at a predetermined interval so as to intersect with the first electrode group, with the remaining of the plurality of strip electrodes as the second electrode group. Forming a plurality of first structures by knitting with a plurality of second electrode groups, crossing the first electrode group and the second electrode group, and knitting in a different overlapping state from the first structure. The first structure body and the second structure body are formed so that the intersecting positions of the first electrode group and the second electrode group in the first structure body and the second structure body are mutually equal. The layers are alternately stacked so as to coincide with each other, and at the intersection position between the adjacent first structure and second structure. When the polarity of the voltage applied to the pair of strip electrodes which face each other adjacent the same, to join the pair of strip-shaped electrodes at intersections.

  According to the present invention, a large-area electrostatic actuator can be easily manufactured.

The figure which shows the electrostatic actuator which concerns on one Embodiment of this invention. Cross section of electrostatic actuator in XZ plane The figure which shows an example of the structure of an electrode tape The figure which shows an example of the 1st plain weave structure and the 2nd plain weave structure The figure explaining an example of the formation method of an electrode tape Sectional drawing in the XZ plane of the electrostatic actuator which concerns on other embodiment of this invention. The figure explaining an example of the formation method of a laminated electrode part The figure explaining another example of the formation method of a laminated electrode part

<< One Embodiment >>
FIG. 1 is an external view of an electrostatic actuator 100 according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the electrostatic actuator 100 on the XZ plane along line AA ′ in FIG.

  As shown in FIG. 3, the electrostatic actuator 100 according to the present embodiment is laminated using an electrode tape 10 that is a band-shaped electrode having a thickness d formed by sandwiching a metal film such as copper between dielectric films. It is a laminated electrostatic actuator formed in this way. Note that voltages having different polarities are applied to the electrode tape 10 extending in the X direction and the Y direction, and this is indicated by white and gray colors.

  Each layer forming the electrostatic actuator 100 of this embodiment includes four sets of electrode tapes 10 each having a width L, and two sets of electrode tapes 10 arranged in parallel on the same plane (XY plane) with a distance D therebetween. It is a structure formed by intersecting and plain weaving. FIG. 4 shows a plain weave state of the electrode tape 10 of the structure constituting each layer. As shown in FIG. 4, the electrostatic actuator 100 includes two types of structures having different overlapping states (hereinafter, FIG. 4A is referred to as “first plain weave structure”, and FIG. Called a "plain weave structure". Therefore, as shown in FIGS. 1 and 2, the crossing position of the electrode tape 10 extending in the X direction and the Y direction between the first plain weave structure and the second plain weave structure is the lamination direction (Z direction). ), The electrostatic actuator 100 is formed by alternately stacking so as to match each other.

  In addition, in laminating the first plain weave structure and the second plain weave structure, as shown in FIG. 2, the first plain weave structure and the second plain weave structure are located at the intersecting positions and have the same polarity. An adhesive is applied and bonded to the portion of the pair of electrode tapes 10 to which the above voltage is applied. As a result, the interval between the electrode tapes 10 having different polarities is maintained by the characteristics such as the elastic force and tension of the electrode tape 10 itself. In the XZ plane, as shown in FIG. 2, the electrode tape 10 extending in the X direction has a honeycomb structure, and in the YZ plane, the electrode tape 10 extending in the Y direction is formed in a honeycomb structure as shown in FIG. It becomes. That is, the electrostatic actuator 100 can stably maintain the shape with its own structure against an external force without causing the first plain weave structure and the second plain weave structure to be displaced from each other. .

  On the other hand, a portion of the electrode tape 10 located at the intersection of the first plain weave structure and the second plain weave structure is a laminated electrode portion 11, and voltages having different polarities are applied to the two sets of electrode tapes 10 of the electrostatic actuator 100. Is applied, voltages of different polarities are applied, and an electric field is generated between the pair of stacked electrode portions 11 facing each other in the stacking direction. An electrostatic force corresponding to the electric field between the pair of laminated electrode portions 11 acts, and the gap d1 between the laminated electrode portions 11 contracts. As a result, the electrostatic actuator 100 contracts in the stacking direction (Z direction) and can obtain a large driving force.

  Here, the magnitude of the electrostatic force per unit area acting between the laminated electrode portions 11 is inversely proportional to the square of the distance between these electrodes. Therefore, in order to generate a large acting force on the electrostatic actuator 100, it is necessary to combine the pair of laminated electrode portions 11 close to each other.

  However, when the distance D between the electrode tapes 10 is reduced, the distance S between the laminated electrode portions 11 of the electrode tape 10 is shortened, and the gap d1 between the laminated electrode portions 11 in the laminating direction is reduced, but the electrostatic actuator 100 The range of the expansion / contraction motion of the lens is also reduced. On the other hand, when the distance D is increased, the distance S between the stacked electrode portions 11 of the electrode tape 10 is increased, and the gap d1 between the stacked electrode portions 11 in the stacking direction can be increased, but the electrode tape 10 is bent. As a result, the electrostatic actuator 100 cannot operate normally and a large driving force cannot be obtained.

  In addition, when the width L of the electrode tape 10 is reduced, it is necessary to manufacture a large amount of electrostatic actuator 100 in order to manufacture a large area electrostatic actuator, which takes time and cost. On the other hand, when the width L is increased, the electrode tape 10 is bent, the electrostatic actuator 100 cannot operate normally, and a large driving force cannot be obtained.

  Therefore, in the present embodiment, for example, the width L of the electrode tape 10 is 2 mm or less, and the distance S between the laminated electrode portions 11 of the electrode tape 10 = the thickness d × 6 to 8 of the electrode tape 10. However, it is preferable to determine appropriately according to the characteristics of the electrode tape 10.

  Next, a method for manufacturing the electrostatic actuator 100 will be described with reference to FIG. FIG. 5 shows an example of a method for forming the electrode tape 10.

  As shown in FIG. 5A, the electrode sheet is formed by sandwiching a copper thin film between PET films. The electrode sheet is cut into a strip shape along a thick broken line (FIG. 5B). The cut surface (arrow in FIG. 5C) of the electrode sheet cut into a strip shape is etched, and the copper thin film exposed on the cut surface is removed. The cut surfaces are joined with the PET films on both sides (FIG. 5D), and the electrode tape 10 is generated (FIG. 5E).

  In the step of FIG. 5B, the electrode sheet is formed with a predetermined margin α in advance so that the width of the strip electrode of the copper thin film becomes the width W by etching the cut surface in the step of FIG. 5C. It is preferable to cut.

  Next, as shown in FIG. 4, one set of four electrode tapes 10 is arranged in parallel on the same plane (XY plane) with a distance D, and two sets of electrode tapes 10 are crossed to overlap each other. A plurality of first plain weave structures and second plain weave structures, each having a different number, are formed. For example, one end of the electrode tape 10 protruding from the plain weave portion is cut at the position of the dotted line shown in FIG. 4 with respect to the first plain weave structure and the second plain weave structure. On the other hand, the protruding portion of the other electrode tape 10 that is not cut is used as a voltage terminal portion to which a dielectric film is removed by etching or the like and a voltage of each polarity is applied. In addition, it is preferable to join together the voltage terminal part of each electrode tape 10 for every polarity of a voltage.

  Then, in laminating the first plain weave structure and the second plain weave structure, as shown in FIG. 2, it is located at the intersection of the first plain weave structure and the second plain weave structure and has the same polarity. An adhesive is applied to the portion of the pair of electrode tapes 10 to which the voltage of 1 is applied. The first plain weave structure and the second plain weave structure are alternately stacked and joined to form the electrostatic actuator 100.

  As described above, in this embodiment, two sets of electrode tapes 10 are crossed and plain woven, and the first plain woven structure and the second plain woven structure having different overlapping states are alternately laminated, thereby obtaining a large area. The electrostatic actuator 100 having the electrode plate can be easily manufactured at low cost.

  Also, by simply laminating the first plain weave structure and the second plain weave structure alternately, it is possible to form a plurality of laminated electrodes arranged in parallel, and against the effects from external forces such as twisting. The electrode structure can be maintained.

Furthermore, since the electrostatic actuator 100 is formed from a simple structure of the first plain weave structure and the second plain weave structure, variations in the size of the electrode plates and the distance between the electrode plates can be suppressed. In addition, it is possible to suppress variations in expansion and contraction operations between the electrostatic actuators.
<< Other embodiments >>
An electrostatic actuator according to another embodiment of the present invention is the same as the electrostatic actuator 100 according to one embodiment shown in FIG. Therefore, among the components of the electrostatic actuator 100 of the present embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The difference between the electrostatic actuator 100 of the present embodiment and that of the one embodiment is that the thickness of the dielectric film of the laminated electrode portion 11 is changed to the electrode tape 10 between the laminated electrode portions 11 as shown in FIG. It is made thicker than the thickness of the dielectric film. That is, by increasing the thickness of the dielectric film of the laminated electrode portion 11, it is possible to avoid bending of the electrode tape 10 in the laminated electrode portion 11, and it is possible to form the laminated electrode portion 11 having a larger area. Become. As a result, the electrostatic actuator 100 can generate a larger driving force.

  On the other hand, the manufacture of the electrostatic actuator 100 of the present embodiment is the same as the manufacture of the one embodiment, and the dielectric film of the electrode tape 10 positioned between the stacked electrode portions 11 has a thickness of the dielectric film of the stacked electrode portion 11. The difference is that the step shown in FIG. 7 is added to make the thickness of the body film thicker.

  That is, for example, each electrode tape 10 shown in FIG. 5 formed by sandwiching a belt-like electrode with a PET film leaves a plateau portion with a width L out of the PET film portions on both sides, and FIG. The part of the width S shown by shading is removed. As shown in FIG. 7B, the electrode tape 10 has a structure in which plateau portions having a width L and grooves 12 having a width S appear alternately. Note that the method of integrally forming the laminated electrode portion 11 and the groove portion 12 in this way is particularly effective when, for example, a fine electrostatic actuator is manufactured by using a lithography technique. Further, the width S of the groove 12 is a variable length, and it is preferable that the width S is appropriately determined according to the characteristics and the like of the electrode tape 10 together with the interval S.

  As described above, in this embodiment, two sets of electrode tapes 10 are crossed and plain woven, and the first plain woven structure and the second plain woven structure having different overlapping states are alternately laminated, thereby obtaining a large area. The electrostatic actuator 100 having the electrode plate can be easily manufactured at low cost.

  Also, by simply laminating the first plain weave structure and the second plain weave structure alternately, it is possible to form a plurality of laminated electrodes arranged in parallel, and against the effects from external forces such as twisting. The electrode structure can be maintained.

  Furthermore, since the electrostatic actuator 100 is formed from a simple structure of the first plain weave structure and the second plain weave structure, variations in the size of the electrode plates and the distance between the electrode plates can be suppressed. In addition, it is possible to suppress variations in expansion and contraction operations between the electrostatic actuators.

Further, by increasing the thickness of the dielectric of the laminated electrode portion 11, it is possible to avoid the bending of the electrode tape 10 at the laminated electrode portion 11 portion and to form the laminated electrode portion 11 having a large area.
<< Additional items of embodiment >>
(1) In the above embodiment, the first plain weave structure and the second plain weave structure are formed by using two sets of four electrode tapes 10 as one set. However, the present invention is not limited to this. The first plain weave structure and the second plain weave structure may be formed from two sets including a plurality of electrode tapes 10 other than four. The number of the two sets of electrode tapes 10 may be different from each other.

  (2) In the above embodiment, two sets of electrode tapes 10 intersect at 90 degrees, but the present invention is not limited to this, and may intersect at an angle other than 90 degrees.

  (3) In the above embodiment, the number of the first plain weave structure and the second plain weave structure is four. However, depending on the movable range required for the electrostatic actuator 100 and the magnitude of the force during contraction. It is preferable to determine the number of layers as appropriate.

  (4) In the above embodiment, an adhesive is applied to the portion of the pair of electrode tapes 10 that are located at the intersections of the adjacent first plain weave structure and second plain weave structure and to which a voltage of the same polarity is applied. And although the 1st plain weave structure and the 2nd plain weave structure were laminated | stacked, this invention is not limited to this. For example, the dielectric film on the bonding side of the part of the electrode tape 10 to be bonded is removed by etching or the like, and a metal film from which the dielectric film has been removed is applied with a conductive adhesive and bonded. Alternatively, the metal film from which the metal is removed may be welded. Thereby, it is not necessary to join at least the voltage terminal portions of the electrode tapes 10 in the stacking direction for each polarity of the applied voltage, and the configuration of the electrostatic actuator 100 can be simplified.

  (5) In the other embodiment, the laminated electrode portion 11 and the groove portion 12 are formed by removing predetermined portions of the PET film sandwiching the belt-like electrode. However, the present invention is not limited to this. For example, as shown in FIG. 8, a square plate-like member having a length L on one side is formed on an electrode tape 10 formed by covering a strip electrode with a thin insulator film, and a groove portion having a desired width S. 12 may be joined to form the stacked electrode portions 11 and the groove portions 12 alternately.

Further, the laminated electrode portion 11 may be formed by combining the electrode tape 10 with another member. For example, when the laminated electrode part 11 is formed by bonding a plate-like member made of a material having a higher rigidity than PET resin such as silica (SiO ₂ ) to the electrode tape 10, the laminated electrode part is formed using PET resin or the like. Compared with the case where 11 is formed, the thickness of the laminated electrode part 11 can be reduced. Thereby, the distance between a pair of opposing laminated electrode parts 11 can be shortened, and the action force of the electrostatic actuator 100 can be increased.

  Furthermore, the electrode tape 10 may be formed by joining plate members made of a resin hardened by mixing glass fibers as described above. Further, the laminated electrode portion 11 is formed by applying and curing an ultraviolet curable resin on a square region having a length L of one side so that the groove portion 12 having a desired width S is formed on both surfaces of the electrode tape. It may be formed. Alternatively, the laminated electrode portion 11 may be formed by applying an ultraviolet curable resin to both surfaces of the electrode tape 10 and irradiating only the region where the laminated electrode portion 11 is to be formed with ultraviolet rays to be cured.

  From the above detailed description, features and advantages of the embodiments will become apparent. It is intended that the scope of the claims extend to the features and advantages of the embodiments as described above without departing from the spirit and scope of the right. Further, any person having ordinary knowledge in the technical field should be able to easily come up with any improvements and modifications, and there is no intention to limit the scope of the embodiments having the invention to those described above. It is also possible to use appropriate improvements and equivalents within the scope disclosed in.

  The electrostatic actuator having the basic configuration described above is small in size, has a large operating range, and can realize a large working force. It can be used as an actuator for moving a joint or the like.

  Further, the electrostatic actuator configured as described above can be used as a pressure sensor.

10 electrode tape, 11 laminated electrode portion, 12 groove portion, 100 electrostatic actuator

Claims (5)

An electrode group composed of a plurality of strip electrodes arranged in parallel on the same plane at a predetermined interval, and the first electrode group and the second electrode group to which voltages of opposite polarities are applied are crossed. A plurality of first structures formed by:
A plurality of second structures formed by crossing the first electrode group and the second electrode group and knitting in an overlapping state different from the first electrode surface;
In the first structure body and the second structure body, the intersecting positions of the first electrode group and the second electrode group in the first structure body and the second structure body respectively coincide with each other. Are stacked alternately,
A pair of adjacent strip electrodes facing each other at the intersecting positions in the adjacent first structure and second structure are joined at the intersecting positions when the polarity of the applied voltage is the same. An electrostatic actuator characterized by The electrostatic actuator according to claim 1,
The electrostatic actuator according to claim 1, wherein the first structure and the second structure are formed by plain weaving. The electrostatic actuator according to claim 1 or 2,
The electrostatic actuator, wherein the strip electrode is covered with a dielectric. The electrostatic actuator according to claim 3, wherein
The electrostatic actuator according to claim 1, wherein the dielectric covers the belt-like electrode thicker at the intersection position than at the intersection position. Forming a plurality of strip electrodes sandwiched between dielectrics having a predetermined thickness;
A part of the plurality of strip electrodes is arranged in parallel at a predetermined interval as a first electrode group,
The remainder of the plurality of strip electrodes is used as a second electrode group, arranged in parallel at the predetermined interval so as to intersect the first electrode group, and knitted with the first electrode group. Forming a first structure of
Crossing the first electrode group and the second electrode group, and forming a plurality of second structures by knitting in an overlapping state different from the first structure;
In the first structure body and the second structure body, the intersection positions of the first electrode group and the second electrode group in the first structure body and the second structure body coincide with each other. And alternately stacked
When the polarity of the voltage applied to a pair of adjacent strip electrodes facing each other is the same at the crossing position in the adjacent first structure and second structure, the pair of strip electrodes is A method for manufacturing an electrostatic actuator, characterized by joining at an intersecting position.

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