JP2005245151A - Electrostatic actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic actuator having a wide deformation controllable region in which deformation characteristics can be set linearly or user's intended characteristics can be set. <P>SOLUTION: The electrostatic actuator for controlling the deformation shape of a resilient movable body 10 by electrostatic attraction acting when a voltage is applied between a movable body electrode 20 and a fixed substrate electrode 40, and by the mechanical restoration force of the resilient movable body 10 is a curled-up electrostatic actuator where the interval between the resilient movable body 10 and a fixed substrate 50 varies gradually from the fixed end toward the forward end and the electrostatic attraction or the bending rigidity of the resilient movable body 10 acting at a predetermined part of the moving body passage from the fixed end to the forward end of the resilient movable body 10 is controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides an electrostatic force that controls the deformed shape of an elastic movable body by an electrostatic attractive force that works by applying a voltage between the movable electrode and the fixed substrate electrode that are arranged to face each other and a mechanical restoring force of the elastic movable body. In particular, the present invention relates to a curled-up electrostatic actuator in which the distance between the elastic movable body and the fixed substrate is gradually changed from the fixed end toward the tip.

  As small-sized portable devices become widespread and further, there is a growing demand for mounting automatic drive parts on portable devices, actuators with small size and low power consumption are desired. Accordingly, electrostatic actuators have been proposed in place of conventional electromagnetic actuators.

  An electrostatic actuator has a relatively simple configuration and obtains a driving force by an electrostatic force, which is suitable for downsizing and low power consumption.

  In addition, by applying so-called MEMS (Micro Electro-Mechanical System) technology to which semiconductor manufacturing technology is applied, low-cost and high-precision production can be expected.

As such an electrostatic actuator, Patent Document 1 proposes an electrostatic microactuator configured as shown in FIG. That is, the electrostatic microactuator 1 includes a substrate 2, a substrate electrode insulating layer 3, a substrate electrode 4, a drive electrode insulating layer 5, and a drive electrode 6. The drive electrode 6 has a spiral shape and is made of an amorphous alloy having a supercooled liquid region. An object to be driven is attached to the 6A portion of the drive electrode 6. Then, it can be driven in the vertical direction along the spiral central axis AA by an electric field generated by applying a voltage between the drive electrode pad portion 7 and the substrate electrode pad portion.
Japanese Patent No. 3210966

  In the configuration disclosed in Patent Document 1, there is no problem when the driving electrode 6 is binary driven to be fully extended or attracted to the substrate 2, but the amount of deformation of the driving electrode 6 can be arbitrarily set. When the analog control to be set is performed, the range in which the deformation amount of the drive electrode 6 can actually be controlled with respect to the initial gap is narrow. The applied voltage and the deformation amount of the drive electrode 6 have a non-linear relationship. Therefore, the electrostatic actuator having the configuration disclosed in Patent Document 1 has many problems in terms of control.

  The present invention has been made in view of the above points, and has a wide area in which deformation can be controlled. Further, the present invention can statically set a deformation characteristic linearly or a characteristic intended by a user. An object is to provide an electric actuator.

In order to achieve the above object, an electrostatic actuator according to an aspect of the present invention includes an electrostatic attractive force that works by applying a voltage between a movable body electrode and a fixed substrate electrode that are arranged to face each other, and an elastic movable body. An electrostatic actuator that controls the deformation shape of the elastic movable body by a mechanical restoring force,
One end of the elastic movable body is a fixed end fixed to the fixed substrate,
The distance between the elastic movable body and the fixed substrate gradually changes from the fixed end to the tip of the elastic movable body,
The electrostatic attraction acting on a predetermined part of the movable body path from the fixed end of the elastic movable body toward the tip or the bending rigidity of the elastic movable body is controlled.

  ADVANTAGE OF THE INVENTION According to this invention, the area | region which can control a deformation | transformation is wide, and the electrostatic actuator which can set a deformation | transformation characteristic linearly or can set it to the characteristic which a user intends can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 2 is a perspective view of a curled up electrostatic actuator to which the present invention is applied. As shown in the figure, the electrostatic actuator includes an elastic movable body 10, a movable body electrode 20, an insulating layer 30, a fixed substrate electrode 40, and a fixed substrate 50. Other configurations such as a configuration in which the elastic movable body 10 includes the movable body electrode 20 and a configuration in which the insulating layer 30 is not formed are possible by forming the elastic movable body 10 with a metal thin film.

  In such a curled-up type electrostatic actuator, one end of the elastic movable body 10 is fixed to the fixed substrate 50 and the other end is separated from the fixed substrate 50. Hereinafter, the fixed side of the elastic movable body 10 is referred to as a fixed end, and the other end is referred to as a tip.

  Next, the operation of the electrostatic actuator having such a configuration will be described.

  In the electrostatic actuator shown in FIG. 2, when a voltage is applied between the movable body electrode 20 and the fixed substrate electrode 40, an electrostatic attractive force acts between both electrodes, and the elastic movable body 10 is attracted to the fixed substrate 50 side. The amount of deformation of the elastic movable body 10 is determined by the mechanical restoring force of the elastic movable body 10 and the electrostatic attractive force acting between both electrodes, and the deformation of the elastic movable body 10 stops when the two forces are balanced. When the electrostatic attractive force acting between both electrodes exceeds the mechanical restoring force of the elastic movable body 10, the elastic movable body 10 is attracted to the fixed substrate 50.

  Next, control of such an electrostatic actuator will be described.

  As described above, the amount of deformation of the elastic movable body 10 of the electrostatic actuator is determined by the mechanical restoring force of the elastic movable body 10 and the electrostatic attractive force acting between both electrodes. By controlling, the deformation amount of the elastic movable body 10 can be controlled. However, in general, the mechanical restoring force of the elastic movable body 10 is proportional to the amount of deformation of the elastic movable body 10, and the electrostatic attractive force acting between both electrodes is proportional to the square of the electric field between both electrodes. It has the following characteristics.

  The amount of deformation of the elastic movable body 10 with respect to the voltage applied between both electrodes is non-linear.

  The sensitivity of the deformation amount of the elastic movable body 10 with respect to the voltage applied between both electrodes is very low in the low voltage region, and rapidly increases at a certain voltage.

  When the voltage applied between the electrodes is increased, the elastic movable body 10 suddenly sticks to the fixed substrate 50 (stacking phenomenon). Therefore, the amount of deformation of the elastic movable body 10 can be controlled in the initial stage of both electrodes. It is about 1/3 of the gap.

  The above-described characteristics will be described in detail using the result of simulating the deformation amount of the elastic movable body 10 with respect to the voltage applied between both electrodes.

Here, the model used for the simulation is shown in FIG. In other words, this model includes the elastic movable body 10 (also serving as the movable body electrode 20 in this example), the insulating layer 30, and the fixed substrate electrode 40. The elastic movable body 10 is assumed to have a curvature of y = 200 × ² , where x is the longitudinal direction of the fixed substrate electrode 40 from the fixed end and y is the vertical direction of the fixed substrate electrode 40 from the fixed end.

  Moreover, the set value of this model, the physical property value of the elastic movable body 10, etc. are as shown below.

Fixed substrate electrode 40 length l = 1000 μm
Fixed substrate electrode 40 width w = 200 μm
Insulating layer 30 thickness di = 0.5 μm
Dielectric constant ε = 4 of insulating layer 30
Longitudinal elastic modulus E = 69.7 GPa of the elastic movable body 10
Sectional moment of inertia I = 1.04 × 10 ^{−21 of the} elastic movable body 10
Curvature y of elastic movable body 10 = 200x ²
FIG. 4 shows a mechanical model of the electrostatic attraction force Fe and the elastic movable body 10 with the horizontal axis representing the height h of the tip of the elastic movable body 10 and the vertical axis representing the voltage applied to both electrodes. It is the graph which showed the restoring force Fr. In this graph, the point where the electrostatic attractive force Fe and the mechanical restoring force Fr are balanced, that is, the intersection of Fe and Fr, indicates the deformation amount of the elastic movable body 10 when a voltage is applied to both electrodes. As can be seen from FIG. 4, the elastic movable body 10 hardly deforms when the voltage applied to both electrodes is low, deforms rapidly at a certain voltage (around 30 V in this simulation result), and further increases the voltage. Then, it sticks to the fixed substrate 50.

  Therefore, in the electrostatic actuator according to the present invention, the electrostatic attractive force acting on a predetermined portion of the movable body path from the fixed end of the elastic movable body 10 toward the tip or the bending rigidity of the elastic movable body 10 is controlled. . Here, the path indicated by the thick arrow line in FIG. 5A means the movable body path 13 from the fixed end 11 to the tip end 12 of the elastic movable body 10 described above, and in FIG. The width shown means the width 14 of the predetermined part of the movable body path 13 described above.

  The elastic movable body 10 of the electrostatic actuator according to the present invention is not limited to the linear shape as shown in FIGS. 2 and 5A, but is a U-shape as shown in FIG. Various shapes such as an (elliptical) arc shape as shown in FIG. 5C and a free shape as shown in FIG. 5D exist, and the movable body path 13 in that case is as shown in the figure.

  Hereinafter, in order to simplify the explanation and illustration, several embodiments will be described by taking the case where the elastic movable body 10 has a linear shape as an example, but various shapes as shown in FIGS. Needless to say, the present invention can also be applied to the elastic movable body 10.

[First Embodiment]
Next, the configuration of the electrostatic actuator according to the first embodiment of the present invention will be described.

  FIG. 1A is a semi-transparent perspective view showing the elastic movable body 10, the movable body electrode 20, and the insulating layer 30 in a transparent manner. FIG. 1B is a top view of the electrostatic actuator as viewed from above. It is. The elastic movable body 10, the movable body electrode 20, and the insulating layer 30 are indicated by broken lines, and the area of the fixed substrate electrode 40 is indicated by oblique lines.

  As shown in FIGS. 1A and 1B, the electrostatic actuator according to this embodiment has a distribution in the width of the fixed substrate electrode 40, so that the movable body electrode 20 with respect to the width of the elastic movable body 10 The ratio of the widths of the opposing regions of the fixed substrate electrode 40 is changed along the movable body path 13.

  The electrostatic attraction generated by applying a voltage between the movable body electrode 20 and the fixed substrate electrode 40 is proportional to the area where the movable body electrode 20 and the fixed substrate electrode 40 overlap. Therefore, the electrostatic attraction acting between both electrodes can be controlled along the movable body path 13 by the above-described configuration.

  Next, the effect of this configuration will be described.

  Using a model similar to the simulation model shown in FIG. 3, the width w of the fixed substrate electrode 40 is set to a shape represented by the following expression, where X is the direction from the fixed end 11 to the tip 12 of the elastic movable body 10. In addition, the electrode represented by the following formula has a shape that becomes gradually thinner toward the tip 12.

w = p / (X + q)
However, p = 22.2 × 10 ^-9
q = 0.11 × 10 ⁻³
In this model, as in the graph shown in FIG. 4, the horizontal axis represents the height h of the tip 12 of the elastic movable body 10, and the vertical axis represents the electrostatic force Fe with the voltage applied to both electrodes as a parameter, A graph showing the dynamic restoring force Fr is shown in FIG. From this graph, the height of the tip 12 when the elastic movable body 10 is deformed with respect to the voltage applied between the two electrodes from the intersection of the electrostatic attractive force Fe and the mechanical restoring force Fr is shown below.

  As described above, the configuration of the present embodiment makes the deformation characteristics of the elastic movable body 10 more linear with respect to the voltage applied to both electrodes and improves controllability compared to the model shown in FIG. It becomes possible to make it.

  Further, when the above-described effects are developed, the following effects are expected.

  FIG. 7 is a diagram showing a deformation amount of the elastic movable body 10 with respect to a voltage applied between the movable body electrode 20 and the fixed substrate electrode 40.

  In the normal configuration, as shown by the waveform A in FIG. 7, the amount of deformation of the elastic movable body 10 with respect to the applied voltage hardly deforms at a low voltage, but gradually increases in sensitivity, rapidly deforms at a certain voltage, and elastically movable. The body 10 sticks to the fixed substrate electrode 40. Here, the waveform A finally having a constant value means that the elastic movable body 10 has stuck to the fixed substrate 50 (deformed by the initial gap).

  On the other hand, as shown in this embodiment, the ratio of the width of the region where the movable body electrode 20 and the fixed substrate electrode 40 face each other to the width of the elastic movable body 10 is appropriately set along the movable body path 13. Thus, as shown in the waveform B of FIG. 7, the deformation characteristic of the elastic movable body 10 with respect to the voltage applied to both electrodes can be set linearly, or as shown in the waveform C, the characteristic intended by the user can be set. It becomes possible. In addition, it is possible to enlarge the region where the deformation of the elastic movable body 10 can be controlled with respect to the initial gap between the movable body electrode 20 and the fixed substrate electrode 40.

  Moreover, the same effect can be acquired even if it uses the following forms other than the above-mentioned form.

  FIG. 8 shows the fixed substrate electrode 40 formed in a mesh shape, and FIG. 9 shows the same mesh shape. With these forms, it is possible to appropriately set the ratio of the fixed substrate electrode 40 per unit area in a predetermined part of the movable body path 13, and the electrostatic attractive force acting between both electrodes can be set along the movable body path 13. Can be controlled appropriately.

[Second Embodiment]
Next, the configuration of the electrostatic actuator according to the second embodiment of the present invention will be described.

  FIG. 10 is a diagram illustrating a configuration of the electrostatic actuator according to the present embodiment. This figure is a diagram schematically showing an electric circuit in which the electrostatic actuator according to the present embodiment is cut at the center and connected to each electrode.

  That is, the electrostatic actuator according to the present embodiment includes the elastic movable body 10 and the movable body electrode 20, the insulating layer 30, the fixed substrate electrode 40 divided into a plurality, the fixed substrate 50, and the variable voltage source group 60. . Each output of the variable voltage source group 60 is connected to the corresponding fixed substrate electrode 40, and all the GNDs are connected to the movable body electrode 20.

  Next, a method for driving the electrostatic actuator according to the present embodiment will be described.

  In a normal electrostatic actuator, the distance between the movable body electrode 20 and the fixed substrate electrode 40 is about several hundreds μm at most. From the aspect ratio of the shape, the electrostatic attractive force acting on the movable body electrode 20 faces each other. The voltage applied to the fixed substrate electrode 40 located in the portion is dominant.

  In the present embodiment, the voltage applied to each fixed substrate electrode 40 is appropriately set by the variable voltage source group 60, and the electrostatic attractive force acting between both electrodes in a predetermined part of the movable body path 13 can be controlled. it can. Therefore, the deformation characteristics of the elastic movable body 10 with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user. In addition, it is possible to enlarge the region where the deformation of the elastic movable body 10 can be controlled with respect to the initial gap between the movable body electrode 20 and the fixed substrate electrode 40.

[Third Embodiment]
Next, the configuration of the electrostatic actuator according to the third embodiment of the present invention will be described.

  FIG. 11 is a diagram illustrating a configuration of the electrostatic actuator according to the present embodiment. This figure is a diagram schematically showing an electric circuit connected to the electrostatic actuator while the electrostatic actuator according to the present embodiment is cut at the center.

  That is, the electrostatic actuator according to the present embodiment includes the elastic movable body 10, the movable body electrode 20, the insulating layer 30, the fixed substrate 50, the variable drive power supply 70, the variable reference power supply 80, and the fixed substrate resistor formed of the resistor. 90 and a variable resistor 100. Here, the variable reference power source 80 is connected to one end of the fixed substrate resistor 90, and the variable resistor 100 is connected to the other end.

  Next, a driving method of the electrostatic actuator according to the present embodiment having such a configuration will be described.

  FIG. 12 is a diagram illustrating an example of the potential of the movable body electrode 20 with respect to the positions of the movable body electrode 20 and the fixed substrate resistor 90, the potential of the fixed substrate resistor 90, and the potential difference between the two electrodes. Here, the potential of the movable body electrode 20 is indicated by a one-dot chain line, the potential of the fixed substrate resistor 90 is indicated by a broken line, and the potential difference between both electrodes is indicated by a solid line.

  The potential C of the movable body electrode 20 is determined by the output of the variable drive power supply 70. The potential A on the elastic movable body fixed end 11 side of the fixed substrate resistor 90 is determined by the output of the variable reference power supply 80, and the potential B on the elastic movable body tip 12 side can be determined by the set value of the variable resistor 100. Accordingly, by setting the resistance values of the variable drive power source 70, the variable reference power source 80, and the variable resistor 100, it is possible to set the increase / decrease in potential difference between both electrodes in the movable body path 13 and the gradient thereof. If the potential of the movable body electrode 20 and the potential of the fixed substrate resistor 90 are set as shown in FIG. 12, the potential difference between both electrodes along the movable body path 13 is set to increase after gradually decreasing. The

  As described above, by using this embodiment, the potentials of the movable body electrode 20 and the fixed substrate resistor 90 are appropriately set along the movable body path 13 and work between both electrodes in a predetermined part of the movable body path 13. By controlling the electrostatic attractive force, the deformation characteristics of the elastic movable body 10 with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user. In addition, it is possible to enlarge the region where the deformation of the elastic movable body 10 can be controlled with respect to the initial gap between the movable body electrode 20 and the fixed substrate electrode 40.

  Here, an example in which the fixed substrate electrode 40 is formed of a resistor as the fixed substrate resistor 90 has been described, but the same effect can be obtained even if the movable body electrode 20 side is formed of a resistor. Of course.

[Fourth Embodiment]
Next, the configuration of the electrostatic actuator according to the fourth embodiment of the present invention will be described.

  The electrostatic attractive force acting between the movable body electrode 20 and the fixed substrate electrode 40 is determined by the voltage applied between the electrodes, the distance between the electrodes, and the dielectric constant.

  In a normal electrostatic actuator, an air layer and an insulating layer 30 exist between the movable body electrode 20 and the fixed substrate electrode 40. The dielectric constant of a silicon oxide film frequently used as the insulating layer 30 in the semiconductor manufacturing technology is about four times that of air. Moreover, the dielectric constant of the insulating layer 30 can be set to various values by using other materials. Moreover, when the thickness of the insulating layer 30 is changed, the ratio of the air between the two electrodes and the insulating layer 30 changes, and the total dielectric constant (the dielectric constant when the air and the insulating layer 30 are regarded as one layer) is adjusted. can do.

  Therefore, the distribution of the electrostatic attractive force acting on the elastic movable body 10 can be obtained by providing a distribution in the dielectric constant of the insulating layer 30 along the movable body path 13 or by providing a distribution in the thickness of the insulating layer 30. Can be set.

  In the semiconductor manufacturing technology, as a method of giving a distribution to the thickness of the insulating layer 30, a protective film having a thickness distribution is formed on the insulating layer 30 by a molding technique, and dry etching is performed to form the insulating layer 30. Various techniques have been proposed, such as transferring the thickness distribution of the protective layer. Further, as a method of giving a distribution to the dielectric constant of the insulating layer 30, it is conceivable to form the insulating layer 30 using a plurality of materials and to have a distribution in the composition along the movable body path 13.

  FIG. 13 is a diagram illustrating a configuration of the electrostatic actuator according to the present embodiment. This figure is a diagram schematically showing an electric circuit connected to the electrostatic actuator while the electrostatic actuator according to the present embodiment is cut at the center.

  That is, the electrostatic actuator according to the present embodiment includes the elastic movable body 10, the movable body electrode 20, the insulating layer 30, the fixed substrate electrode 40, the fixed substrate 50, and the variable drive power supply 70. The insulating layer 30 has a thickness distributed along the movable body path 13. By changing the thickness of the insulating layer 30 in this manner, the distribution of the total dielectric constant at a predetermined portion along the movable body path 13 can be given, and the distribution of the electrostatic attractive force acting on the elastic movable body 10 can be set. .

  As described above, by using the present embodiment, the thickness of the insulating layer 30 or the dielectric constant is appropriately set, and the electrostatic attractive force acting between both electrodes in a predetermined part of the movable body path 13 is controlled, The deformation characteristics of the elastic movable body 10 with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user. In addition, it is possible to enlarge the region where the deformation of the elastic movable body 10 can be controlled with respect to the initial gap between the movable body electrode 20 and the fixed substrate electrode 40.

[Fifth Embodiment]
Next, the configuration of the electrostatic actuator according to the fifth embodiment of the present invention will be described.

  The amount of deformation of the elastic movable body 10 is determined by the mechanical restoring force of the elastic movable body 10 and the electrostatic attractive force acting between both electrodes, and when the two forces are balanced, the deformation of the elastic movable body 10 stops. Here, the mechanical restoring force of the elastic movable body 10 is determined by a geometric shape represented by the thickness of the elastic movable body 10 and a physical property value represented by an elastic coefficient. Therefore, by setting the distribution of the thickness of the elastic movable body 10 along the movable body path 13 or the distribution of the elastic coefficient, the bending rigidity of the elastic movable body 10, that is, the distribution of the mechanical restoring force is set. can do.

  As described above, as a method of controlling the thickness or elastic coefficient of the elastic movable body 10, a method of transferring the thickness distribution of the protective film as described in the fourth embodiment, or a method of using a composite material is used. Can be considered.

  FIG. 14 is a diagram illustrating a configuration of the electrostatic actuator according to the present embodiment. This figure is a diagram schematically showing an electric circuit connected to the electrostatic actuator while the electrostatic actuator according to the present embodiment is cut at the center.

  That is, the electrostatic actuator according to the present embodiment includes the elastic movable body 10, the movable body electrode 20, the insulating layer 30, the fixed substrate electrode 40, the fixed substrate 50, and the variable drive power supply 70. The elastic movable body 10 is distributed in thickness along the movable body path 13. As described above, by providing a distribution of the thickness of the elastic movable body 10 along the movable body path 13, the distribution can be set in the bending rigidity of the elastic movable body 10.

  In the example shown in FIG. 14, the thickness of the elastic movable body 10 is gradually increased along the movable body path 13 from the fixed end 11 toward the tip 12. By setting it as such a structure, the bending rigidity of the elastic movable body 10 becomes strong gradually, and a mechanical restoring force will increase. Therefore, it is possible to obtain the same effect as the configuration in which the width of the fixed substrate electrode 40 is gradually narrowed along the movable body path 13 as shown in the first embodiment.

  As described above, by using the present embodiment, the thickness or elastic coefficient of the elastic movable body 10 is appropriately set, and the bending rigidity of the elastic movable body 10 at a predetermined portion of the movable body path 13 is controlled, The deformation characteristics of the elastic movable body 10 with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user. In addition, it is possible to enlarge the region where the deformation of the elastic movable body 10 can be controlled with respect to the initial gap between the movable body electrode 20 and the fixed substrate electrode 40.

  Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and various modifications and applications are naturally possible within the scope of the gist of the present invention.

(Appendix)
The invention having the following configuration can be extracted from the specific embodiment.

(1) The deformation shape of the elastic movable body is controlled by an electrostatic attractive force that works by applying a voltage between the movable electrode and the fixed substrate electrode that are arranged to face each other and a mechanical restoring force of the elastic movable body. An electrostatic actuator,
One end of the elastic movable body is a fixed end fixed to the fixed substrate,
The distance between the elastic movable body and the fixed substrate gradually changes from the fixed end to the tip of the elastic movable body,
An electrostatic actuator, wherein electrostatic attraction acting on a predetermined part of a movable body path from the fixed end of the elastic movable body toward the tip or the bending rigidity of the elastic movable body is controlled.

(Corresponding embodiment)
The first to fifth embodiments correspond to the embodiments related to the electrostatic actuator described in (1).

(Function and effect)
The electrostatic actuator described in (1) controls the configuration of the electrode, the configuration or composition of the insulating layer, the voltage application method, the shape or composition of the elastic movable body, and the like in the movable body path.

  Therefore, according to the electrostatic actuator described in (1), the electrostatic attractive force acting between the two electrodes at a predetermined portion of the movable body path or the bending rigidity of the elastic movable body is controlled to be applied to both electrodes. It is possible to set the deformation characteristics of the elastic movable body with respect to the voltage linearly or to the characteristics intended by the user. In addition, it is possible to enlarge a region where the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode.

  (2) By configuring the ratio of the width of the portion of the movable body electrode and the fixed substrate electrode facing each other to the width of the elastic movable body so as to change along the movable body path, the predetermined portion of the movable body path The electrostatic actuator according to (1), wherein the electrostatic attraction force is controlled.

(Corresponding embodiment)
The embodiment relating to the electrostatic actuator described in (2) corresponds to the first embodiment.

(Function and effect)
The electrostatic actuator described in (2) has a distribution in which the width of the fixed substrate electrode facing the movable body electrode is narrower than that of the elastic movable body. In addition, you may comprise so that a movable body electrode may be combined by forming an elastic movable body with a metal member.

  Therefore, according to the electrostatic actuator described in (2), by controlling the electrostatic attractive force acting between both electrodes in a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (3) The electrostatic actuator according to (2), wherein a ratio of a width of at least one of the movable body electrode and the fixed substrate electrode to a width of the elastic movable body varies along the movable body path.

(Corresponding embodiment)
The embodiment relating to the electrostatic actuator described in (3) corresponds to the first embodiment.

(Function and effect)
The electrostatic actuator described in (3) has a distribution in which the shape of the fixed substrate electrode facing the movable body electrode is narrower than that of the elastic movable body.

  Therefore, according to the electrostatic actuator described in (3), by controlling the electrostatic attractive force acting between both electrodes at a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (4) The electrostatic attractive force at a predetermined portion of the movable body path is controlled by configuring at least one of the movable body electrode and the fixed substrate electrode in a mesh shape or a mesh shape. Electrostatic actuator.

(Corresponding embodiment)
The embodiment relating to the electrostatic actuator described in (4) corresponds to the first embodiment.

(Function and effect)
In the electrostatic actuator described in (4), the shape of the fixed substrate electrode facing the movable body electrode is a mesh shape or a mesh shape. In addition, you may comprise so that a movable body electrode may be combined by forming an elastic movable body with a metal member.

  Therefore, according to the electrostatic actuator described in (4), by controlling the electrostatic attractive force acting between both electrodes in a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (5) The ratio of the area of the meshed or meshed electrode to the area of the electrode that is not meshed or meshed varies along the movable body path (4) The electrostatic actuator described in 1.

(Corresponding embodiment)
The embodiment relating to the electrostatic actuator described in (5) corresponds to the first embodiment.

(Function and effect)
In the electrostatic actuator described in (5), the shape of the fixed substrate electrode facing the movable body electrode is a mesh shape or a mesh shape, and the electrode area is changed along the movable body path.

  Therefore, according to the electrostatic actuator described in (5), by controlling the electrostatic attractive force acting between the two electrodes at a predetermined portion of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (6) Controlling the electrostatic attractive force at a predetermined portion of the movable body path by configuring the potential difference between the movable body electrode and the fixed substrate electrode to have a distribution along the movable body path. The electrostatic actuator according to (1), which is characterized.

(Corresponding embodiment)
The embodiment relating to the electrostatic actuator described in (6) corresponds to the second and third embodiments.

(Function and effect)
In the electrostatic actuator described in (6), the potential difference between the movable body electrode and the fixed substrate electrode is distributed along the movable body path.

  Therefore, according to the electrostatic actuator described in this (6), by controlling the electrostatic attraction acting between both electrodes at a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

(7) Either the movable body electrode or the fixed substrate electrode is formed by being divided along the movable body path,
The electrostatic actuator according to (6), wherein means for applying an arbitrary voltage to each of the divided electrodes is provided.

(Corresponding embodiment)
The second embodiment corresponds to the embodiment related to the electrostatic actuator described in (7).

(Function and effect)
In the electrostatic actuator described in (7), the fixed substrate electrode is divided into a plurality along the movable body path, and a variable voltage source group capable of controlling the voltage applied to each electrode is connected. is there.

  Therefore, according to the electrostatic actuator described in (7), by controlling the electrostatic attractive force acting between both electrodes at a predetermined portion of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (8) The electrostatic actuator according to (7), wherein the potential difference between the divided electrode and the non-divided electrode decreases along the movable body path.

(Corresponding embodiment)
The second embodiment corresponds to the embodiment related to the electrostatic actuator described in (8).

(Function and effect)
In the electrostatic actuator described in (8), the fixed substrate electrode is divided into a plurality along the movable body path, and a variable voltage source group capable of controlling a voltage applied to each electrode is connected to the variable voltage source. The group output is set to decrease along the movable body path.

  Therefore, according to the electrostatic actuator described in (8), by controlling the electrostatic attractive force acting between the two electrodes at a predetermined portion of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The region in which the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode can be enlarged.

(9) Either the movable body electrode or the fixed substrate electrode is formed of a resistor,
The electrostatic actuator according to (6), wherein a potential difference is applied to both ends of the electrode formed of the resistor.

(Corresponding embodiment)
The embodiment relating to the electrostatic actuator described in (9) corresponds to the third embodiment.

(Function and effect)
The electrostatic actuator described in (3) is a closed circuit in which a movable body electrode or a fixed substrate electrode is formed of a resistor, a variable voltage source is connected to one end of the resistor, and a variable resistor is connected to the other end. It is what.

  Therefore, according to the electrostatic actuator described in (3), by controlling the electrostatic attractive force acting between both electrodes at a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (10) The thickness of the insulating layer formed on the surface of the fixed substrate electrode facing the movable body electrode is configured to change along the movable body path. The electrostatic actuator according to (1), wherein the electrostatic attraction is controlled.

(Corresponding embodiment)
The fourth embodiment corresponds to the embodiment relating to the electrostatic actuator described in (10).

(Function and effect)
In the electrostatic actuator described in (10), for example, the etching amount of the insulating layer is controlled along the movable body path to change the thickness of the insulating layer.

  Therefore, according to the electrostatic actuator described in (10), by controlling the electrostatic attractive force acting between the two electrodes at a predetermined portion of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (11) The electrostatic actuator according to (10), wherein the thickness of the insulating layer is gradually increased along the movable body path.

(Corresponding embodiment)
The fourth embodiment corresponds to the embodiment related to the electrostatic actuator described in (11).

(Function and effect)
The electrostatic actuator described in (11) is controlled such that the etching amount of the insulating layer gradually decreases along the movable body path from the fixed end to the tip, and the thickness of the insulating layer is gradually increased. It is.

  Therefore, according to the electrostatic actuator described in (11), by controlling the electrostatic attractive force acting between both electrodes in a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The region in which the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode can be enlarged.

  (12) The dielectric constant of the insulating layer formed on the surface of the fixed substrate electrode facing the movable body electrode is configured to change along the movable body path. The electrostatic actuator according to (1), wherein the electrostatic attraction is controlled.

(Corresponding embodiment)
The embodiment related to the electrostatic actuator described in (12) corresponds to the fourth embodiment.

(Function and effect)
In the electrostatic actuator described in (12), the dielectric constant is changed by changing the composition of the insulating layer along the movable body path by using, for example, a composite material for the insulating layer.

  Therefore, according to the electrostatic actuator described in (12), by controlling the electrostatic attractive force acting between both electrodes in a predetermined part of the movable body path, and balancing the mechanical restoring force of the elastic movable body, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (13) The electrostatic actuator according to (12), wherein the dielectric constant of the insulating layer is gradually lowered along the movable body path.

(Corresponding embodiment)
The fourth embodiment corresponds to the embodiment related to the electrostatic actuator described in (13).

(Function and effect)
In the electrostatic actuator described in (13), the dielectric constant is gradually lowered by changing the composition of the insulating layer along the movable body path by using, for example, a composite material for the insulating layer.

  Therefore, according to the electrostatic actuator described in (13), the electrostatic attraction force acting between both electrodes at a predetermined portion of the movable body path is controlled to balance the mechanical restoring force of the elastic movable body. Thus, the region in which the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode can be enlarged.

  (14) The bending rigidity of the elastic movable body at a predetermined portion of the movable body path is controlled by configuring the elastic movable body so that the thickness of the elastic movable body changes along the movable body path (1). ) Electrostatic actuator described in).

(Corresponding embodiment)
The fifth embodiment corresponds to the embodiment of the electrostatic actuator described in (14).

(Function and effect)
In the electrostatic actuator described in (14), the thickness of the elastic movable body is changed by, for example, partially etching the movable movable body after the elastic movable body is formed.

  Therefore, according to the electrostatic actuator described in (14), by controlling the mechanical restoring force of the elastic movable body at a predetermined portion of the movable body path and balancing the electrostatic attractive force acting between both electrodes, The deformation characteristics of the elastic movable body with respect to the voltage applied to both electrodes can be set linearly or set to the characteristics intended by the user.

  (15) The electrostatic actuator according to (14), wherein the thickness of the elastic movable body is gradually increased along the movable body path.

(Corresponding embodiment)
The fifth embodiment corresponds to the embodiment related to the electrostatic actuator described in (15).

(Function and effect)
The electrostatic actuator described in (15) is obtained by gradually increasing the thickness of the elastic movable body by, for example, partially etching the movable movable body after forming the elastic movable body.

  Therefore, according to the electrostatic actuator described in (15), by controlling the mechanical restoring force of the elastic movable body at a predetermined portion of the movable body path and balancing the electrostatic attractive force acting between both electrodes, The region in which the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode can be enlarged.

  (16) The elastic rigidity of the elastic movable body at a predetermined portion of the movable body path is controlled by configuring the elastic coefficient of the elastic movable body to change along the movable body path (1). ) Electrostatic actuator described in).

(Corresponding embodiment)
The fifth embodiment corresponds to the electrostatic actuator described in (16).

(Function and effect)
In the electrostatic actuator described in (16), an elastic movable body is formed of a composite material, for example, and the elastic modulus is changed by changing the composition along the path of the movable body.

  Therefore, according to the electrostatic actuator described in (16), by controlling the mechanical restoring force of the elastic movable body at a predetermined portion of the movable body path and balancing the electrostatic attractive force acting between both electrodes, The region in which the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode can be enlarged.

  (17) The electrostatic actuator according to (16), wherein an elastic coefficient of the elastic movable body is gradually increased along the movable body path.

(Corresponding embodiment)
The fifth embodiment corresponds to the embodiment related to the electrostatic actuator described in (17).

(Function and effect)
In the electrostatic actuator described in (17), the elastic movable body is formed of, for example, a composite material, and the composition is changed along the path of the movable body to gradually increase the elastic coefficient.

  Therefore, according to the electrostatic actuator described in (17), by controlling the mechanical restoring force of the elastic movable body at a predetermined portion of the movable body path and balancing the electrostatic attractive force acting between both electrodes, The region in which the deformation of the elastic movable body can be controlled with respect to the initial gap between the movable body electrode and the fixed substrate electrode can be enlarged.

(A) is a semi-transparent perspective view showing the electrostatic actuator according to the first embodiment of the present invention through the elastic movable body, the movable body electrode, and the insulating layer, and (B) is a static perspective view according to the first embodiment. It is the top view which looked at the electric actuator from the upper part. It is a perspective view for demonstrating the structure of the curl-up type electrostatic actuator to which this invention is applied. It is a figure which shows the model used for the simulation of the deformation amount of the elastic movable body with respect to the voltage applied between a movable body electrode and a fixed board | substrate electrode. In the model of FIG. 3, the relationship between the electrostatic attractive force Fe and the mechanical restoring force Fr of the elastic movable body with the horizontal axis representing the height h of the tip of the elastic movable body and the vertical axis representing the voltage applied to both electrodes as parameters. FIG. (A) thru | or (D) is a figure for demonstrating a movable body path | route, respectively. It is a figure which shows the relationship between the electrostatic attraction force Fe in the electrostatic actuator which concerns on 1st Embodiment, and the mechanical restoring force Fr of an elastic movable body. It is the figure which showed the deformation amount of the elastic movable body with respect to the voltage applied between the movable body electrode and fixed substrate electrode in the electrostatic actuator which concerns on 1st Embodiment. It is a top view of the electrostatic actuator which formed the fixed board | substrate electrode in the mesh form as a modification of 1st Embodiment. FIG. 10 is a top view of an electrostatic actuator in which fixed substrate electrodes are formed in a mesh shape as another modification of the first embodiment. It is a figure which shows the structure of the electrostatic actuator which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure of the electrostatic actuator which concerns on 3rd Embodiment of this invention. It is a figure which shows the example of the electric potential of the movable body electrode with respect to the position of the movable body electrode and fixed board | substrate resistor in the electrostatic actuator which concerns on 3rd Embodiment, the electric potential of a fixed board | substrate resistor, and the electric potential difference between both electrodes. It is a figure which shows the structure of the electrostatic actuator which concerns on 4th Embodiment of this invention. It is a figure which shows the structure of the electrostatic actuator which concerns on 5th Embodiment of this invention. It is a perspective view which shows the structure of the conventional electrostatic actuator disclosed by patent document 1. FIG.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 10 ... Elastic movable body, 11 ... Fixed end, 12 ... Tip, 13 ... Movable body path | route, 20 ... Movable body electrode, 30 ... Insulating layer, 40 ... Fixed substrate electrode, 50 ... Fixed substrate, 60 ... Variable voltage source group, 70: Variable drive power supply, 80 ... Variable reference power supply, 90 ... Fixed substrate resistor, 100 ... Variable resistance.

Claims (17)

An electrostatic actuator that controls the deformation shape of the elastic movable body by an electrostatic attractive force that works by applying a voltage between the movable body electrode and the fixed substrate electrode that are arranged opposite to each other and a mechanical restoring force of the elastic movable body Because
One end of the elastic movable body is a fixed end fixed to the fixed substrate,
The distance between the elastic movable body and the fixed substrate gradually changes from the fixed end to the tip of the elastic movable body,
An electrostatic actuator, wherein an electrostatic attractive force acting on a predetermined portion of a movable body path from a fixed end of the elastic movable body toward a tip or a bending rigidity of the elastic movable body is controlled.   By configuring the ratio of the width of the portion of the movable body electrode and the fixed substrate electrode facing each other to the width of the elastic movable body so as to change along the movable body route, The electrostatic actuator according to claim 1, wherein the electrostatic force is controlled.   3. The electrostatic actuator according to claim 2, wherein a ratio of a width of at least one of the movable body electrode and the fixed substrate electrode to a width of the elastic movable body changes along the movable body path.   The electrostatic attraction at a predetermined part of the movable body path is controlled by configuring at least one of the movable body electrode and the fixed substrate electrode in a mesh shape or a mesh shape. Actuator.   5. The ratio of the area of the meshed or meshed electrode to the area of the electrode not meshed or meshed varies along the movable body path. Electrostatic actuator.   The electrostatic attraction force at a predetermined portion of the movable body path is controlled by providing a potential difference between the movable body electrode and the fixed substrate electrode so as to have a distribution along the movable body path. The electrostatic actuator according to claim 1. Either the movable body electrode or the fixed substrate electrode is formed by being divided along the movable body path,
7. The electrostatic actuator according to claim 6, further comprising means for applying an arbitrary voltage to each of the divided electrodes.   The electrostatic actuator according to claim 7, wherein a potential difference between the divided electrode and the non-divided electrode decreases along the movable body path. Either the movable body electrode or the fixed substrate electrode is formed of a resistor,
The electrostatic actuator according to claim 6, wherein a potential difference is applied to both ends of the electrode formed of the resistor.   By configuring the thickness of the insulating layer formed on the surface of the fixed substrate electrode facing the movable body electrode to change along the movable body path, the electrostatic attractive force at a predetermined portion of the movable body path can be reduced. The electrostatic actuator according to claim 1, wherein the electrostatic actuator is controlled.   The electrostatic actuator according to claim 10, wherein a thickness of the insulating layer is gradually increased along the movable body path.   By constructing the dielectric constant of the insulating layer formed on the surface of the fixed substrate electrode facing the movable body electrode so as to change along the movable body path, the electrostatic attraction force at a predetermined part of the movable body path is reduced. The electrostatic actuator according to claim 1, wherein the electrostatic actuator is controlled.   The electrostatic actuator according to claim 12, wherein a dielectric constant of the insulating layer is gradually lowered along the movable body path.   The bending rigidity of the elastic movable body at a predetermined portion of the movable body path is controlled by configuring the elastic movable body so that the thickness thereof changes along the movable body path. Electrostatic actuator.   The electrostatic actuator according to claim 14, wherein the thickness of the elastic movable body is gradually increased along the path of the movable body.   The bending rigidity of the elastic movable body at a predetermined portion of the movable body path is controlled by configuring the elastic coefficient of the elastic movable body to change along the movable body path. Electrostatic actuator.   The electrostatic actuator according to claim 16, wherein an elastic coefficient of the elastic movable body is gradually increased along the movable body path.

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