JP2012044747A - Electrostatic induction generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic induction generation device having high generation efficiency.SOLUTION: An electrostatic induction generation device 1 includes: a diaphragm 30 as a movable electrode; electrets 60 and 70 arranged on both sides of the diaphragm 30; and a case member having an upper case 10 and a lower case 20. An outer edge of the diaphragm 30 is fixed entirely or partially by the case member. A central part 36 of the diaphragm 30, which faces the electrets 60 and 70, vibrates in a direction perpendicular to the electrets 60 and 70. The vibration of the diaphragm 30 induces charge transfer between the electrets 60 and 70 and the diaphragm 30, thereby allowing efficient power generation.

Description

  The present invention relates to an electrostatic induction power generation device having an electret and a diaphragm.

  In a device that converts minute environmental vibration energy due to low-frequency environmental vibration that exists on a daily basis into electric power, an electret formed in a comb-like shape and a movable element arranged to face this electret with a gap There has been proposed a power generation device that generates power by electrostatic induction that includes an electrode, vibrates the movable electrode horizontally with respect to the electret, and extracts the amount of change in the charge induced in the movable electrode as a current (for example, Patent Documents) 1).

WO 2008/026407 pamphlet

In Patent Document 1 described above, since the movable electrode vibrates horizontally with respect to the electret, the first electrode and the electret film of the movable electrode are formed in a comb shape, and the first electrode and the electret film face each other. In this structure, power is generated by relatively moving between a position and a position spaced apart in the horizontal direction. Since the environmental vibration is a low frequency and a small amplitude, and the electrostatic induction is proportional to the crossing area, the first electrode and the electret film must form a large number of comb-like electrodes at a small pitch.
Further, it is required that the position (shape) of the first electrode and the electret film be accurately regulated between a position facing in the horizontal direction and a position separating from the position.

  Therefore, the relative positional accuracy between the first electrode of the movable electrode and the electret film must be managed with high accuracy. However, since the movable electrode is manufactured and assembled in a separate process from the electret, it is difficult to form the relative positional accuracy between the first electrode of the movable electrode and the electret film with high accuracy, and the manufacturing load increases. There is a problem that it ends up.

  In addition, since the elastic portions (or elastic members) are formed at both ends in the vibration direction of the movable electrode in order to vibrate the movable electrode, the structure becomes complicated and it is difficult to control the vibration followability of the elastic portion with respect to environmental vibration. There is a problem of being.

  Further, since the distance between the movable electrode and the electret film is about several tens of μm, when the movable electrode is displaced in the thickness direction due to environmental vibration, the movable electrode and the electret film are rubbed to cause a vibration load. It is conceivable that the contact surface wears out.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 An electrostatic induction power generating device according to this application example is provided so as to be opposed to an electret with a gap from the electret, and the entire periphery or a part of the peripheral portion is fixed, and the central portion Is provided with a diaphragm that vibrates in a direction perpendicular to the electret, and a case member that stores the electret and the diaphragm.
The diaphragm is a movable electrode facing the electret.

  According to such a configuration, since the diaphragm vibrates in the vertical direction with respect to the electret, it is not necessary to form each into a comb-like electrode as in the prior art that vibrates in the horizontal direction. Since the opposing area (intersection area) and the interval are the main elements that govern the amount of power generation, the structure and shape are simplified, and the respective dimensions can be easily managed. Therefore, the number of manufacturing steps can be reduced as compared with the prior art.

  In addition, the diaphragm corresponding to the movable electrode of the prior art described above has elasticity in the diaphragm itself, so that it is not necessary to form an elastic part or an elastic member, the structure becomes simpler, and vibration follow-up to environmental vibration Sex control can also be easily performed.

  Furthermore, in the structure of this application example, even if the diaphragm and the electret are in contact with each other due to environmental vibration, there is no loss due to the contact itself becoming a load, and the occurrence of wear on the contact surface is small.

  Application Example 2 In the electrostatic induction power generating device according to the application example described above, it is preferable that the electrets are disposed on both sides in the vibration direction of the diaphragm.

  As described above, the diaphragm vibrates in the direction perpendicular to the electret. Therefore, by providing electrets on both sides in the vibration direction of the diaphragm, it is possible to obtain approximately twice the power generation efficiency as compared with the case where the diaphragm is disposed only on one side.

  Application Example 3 In the electrostatic induction power generating device according to the application example described above, it is preferable that an insulating film is provided on at least a surface of the diaphragm facing the electret.

  Although details will be described in the embodiment, the power generation amount increases as the diaphragm is brought closer to the electret. However, if the diaphragm is brought close to the electret as much as possible (that is, the contact position), vibration may be hindered by the mutual attractive force (electrostatic force) due to static electricity. Therefore, by providing an insulating film on the surface of the diaphragm facing the electret, the diaphragm and electret are not in direct contact, and a gap corresponding to the thickness of the insulating film is created. Can be reduced. In other words, since the amount of displacement of the diaphragm can be increased in a range where the diaphragm and the electret do not directly contact, there is an effect that the power generation efficiency can be increased.

  In addition, if an insulating film made of the same material is provided on both opposing surfaces of the diaphragm and the electret, charging due to contact can be prevented.

  Application Example 4 In the electrostatic induction power generating device according to the application example described above, it is desirable that the internal pressure of the case member is reduced to a pressure lower than the atmospheric pressure.

  When air is present inside the case member, vibration of the diaphragm may be hindered by a damping phenomenon (sometimes called a pumping phenomenon). Therefore, the damping phenomenon can be suppressed by keeping the inside of the case member in a reduced pressure state. Therefore, it is more preferable to reduce the pressure inside the case member to a vacuum or a state close to vacuum.

  Application Example 5 In the electrostatic induction power generating device according to the application example described above, the restoring elastic force of the diaphragm when the diaphragm comes into contact with the electret due to vibration is due to static electricity between the diaphragm and the electret. It is desirable that it is larger than the adsorption force.

  With this configuration, when the diaphragm has a large amplitude and contacts the electret, even if the diaphragm is attracted by electrostatic force, the adsorption is released by the restoring elastic force. It is possible to vibrate following this.

Application Example 6 In the electrostatic induction power generating device according to the application example described above, the diaphragm is a region having rigidity smaller than that of the central portion between the fixed portion of the peripheral portion and the central portion facing the electret. It is desirable to have
Here, as a configuration method of the region having a lower rigidity than the central portion, for example, a method of forming a thin portion between the fixed portion and the central portion (opposing surface) or a method of connecting with a thin beam can be adopted. .

  In this way, the diaphragm can easily follow the environmental vibration, and the facing surfaces of the diaphragm and the electret can be maintained in a parallel state, so that a predetermined facing area can be ensured, so that power generation efficiency can be increased. .

Application Example 7 In the electrostatic induction power generating device according to the application example described above, it is preferable that a weight portion is formed at a central portion of the diaphragm facing the electret.
In addition, as a weight part, it can be easily formed by making the opposing part with an electret thicker than the circumference | surroundings, for example.

  In this way, the amount of displacement of the diaphragm can be increased, so that charging efficiency (that is, power generation efficiency) can be increased.

  Application Example 8 In the electrostatic induction power generating device according to the application example, it is preferable that a plurality of the diaphragms and the electrets are arranged in an array.

When the combination of one diaphragm and electret is one element, a power generation device having a large power generation amount as a whole can be realized by forming a plurality of aggregates.
In addition, as an aggregate | assembly, it is good also as one element arrange | positioned at equal intervals or random arrangement | positioning.

A sectional view showing the basic composition of the electrostatic induction power generation device concerning a 1st embodiment. Sectional drawing which shows a state when a diaphragm is displaced to the illustration arrow direction by vibration. The circuit diagram which shows the outline of a circuit structure. The graph showing the relationship between the amplitude of a diaphragm and a power generation rate. The graph showing the relationship between the thickness of a diaphragm and the voltage (electret electric potential) required for contact | abutting holding | maintenance with the electret of a diaphragm. Sectional drawing which shows the electrostatic induction electric power generation device which concerns on the modification 1. As shown in FIG. The top view which shows the electrostatic induction electric power generation device which concerns on the modification 2. FIG. The electrostatic induction electric power generation device which concerns on the modification 3 is shown, (a) is a top view, (b) is sectional drawing which shows the AA cut surface of (a).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the figure referred in the following description is a schematic diagram from which the vertical and horizontal scales of a member thru | or a part differ from an actual thing on account of illustration.
(First embodiment)

  FIG. 1 is a cross-sectional view showing the basic configuration of the electrostatic induction power generating device according to the first embodiment. The electrostatic induction power generating device 1 includes an upper case 10 and a lower case 20 constituting a case member, a diaphragm 30 fixed between the upper case 10 and the lower case 20, and an electret 60 provided on the upper case 10. The electret 70 is provided in the lower case 20.

  The upper case 10 and the lower case 20 are glass cases having concave portions 11 and 21, respectively. The upper electrode 40 and the electret 60 are laminated on the inner bottom surface 12 of the concave portion of the upper case 10. A lower electrode 50 and an electret 70 are stacked on the inner bottom surface 22 of the recess.

  In this embodiment, the vibration plate 30 is made of a rectangular Si substrate having a thickness of about 3 μm, and the opposite peripheral edges in the longitudinal direction are fixed by the edge 13 of the upper case 10 and the edge 23 of the lower case 20. Yes. This fixing is performed by anodic bonding, and the space inside the case formed by the recesses 11 and 21 is hermetically sealed in a state where the pressure is reduced from the external atmospheric pressure. It is more desirable that this space is in a vacuum or a state close to a vacuum. Insulating films 38 and 39 are provided on the surfaces of the diaphragm 30 facing the electret 60 and the electret 70, respectively. The insulating films 38 and 39 can be omitted.

  Further, it is desirable that the diaphragm 30 and the electrets 60 and 70 are subjected to high-temperature vacuum treatment to remove moisture on the surface before being sealed and fixed by the case member.

  In this embodiment, the gap dimension d1 between the insulating film 38 and the surface of the electret 60 and the gap dimension d2 between the insulating film 39 and the surface of the electret 70 are set to 50 nm.

  When an adhesive or the like is used as a joining method of the upper case 10, the diaphragm 30, and the lower case 20, the gap dimensions d1 and d2 also fluctuate due to dimensional fluctuations in the thickness of the adhesive, thereby affecting power generation efficiency. I get out. Since the gap size of this embodiment is as small as 50 nm and is susceptible to variations in the thickness of the adhesive, in this embodiment, bonding is performed by an anodic bonding method.

Next, one state when the diaphragm 30 vibrates will be described.
FIG. 2 is a cross-sectional view showing a state when the diaphragm is displaced in the direction of the arrow shown by the vibration. The illustrated state illustrates a state in which the insulating film 39 of the diaphragm 30 is displaced until just before the insulating film 39 contacts the surface of the electret 70. When the diaphragm 30 is displaced in the reverse direction, the diaphragm 30 is displaced until just before the insulating film 38 contacts the surface of the electret 60.

Subsequently, a circuit relating to power generation according to the present embodiment will be described.
FIG. 3 is a circuit diagram showing an outline of a circuit configuration according to the present embodiment. The electret 60 and the electret 70 are connected via the upper electrode 40 and the lower electrode 50, respectively, and a load resistance R is connected between the diaphragm 30. One end of the load resistor R is grounded (GND), and the other end is connected to the output terminal. It is considered that a capacitor is formed between the electret 60 and the diaphragm 30, and between the electret 70 and the diaphragm 30, and the capacitor and the load resistance R are connected in parallel.

  When the vibration plate 30 vibrates, electric power is generated between the electrets 60 and 70 and the vibration plate 30 to generate electric power. When storing the generated power, the battery 100 is connected to the load resistor R in parallel.

  Next, the power generation operation of the electrostatic induction power generation device 1 configured as described above will be described. In this embodiment, it has the diaphragm 30 and the electrets 60 and 70 as a counter electrode (movable electrode). Here, a gap dimension between the insulating film 38 and the electret 60 (sometimes referred to as Gap) is d1, a capacitance between the two is C1, and a potential difference generated by the electret effect is V1. Further, assuming that the gap dimension (may be expressed as Gap) between the insulating film 39 and the electret 70 is d2, the capacitance between both is C2, and the potential difference generated by the electret effect is V2, the circuit of FIG. The total amount of electrostatic energy U stored can be expressed by Equation (1).

  Here, C1 and C2 are capacitances, and the capacitance Ci can be expressed by the following equation, where the dielectric constant ε0 in vacuum, the relative dielectric constant ε, and the facing area are S.

  Here, when V1 = V2, the electrostatic energy U stored in the circuit can be expressed by the following equation.

  Here, if d1 + d2 = d (constant), the electrostatic energy U can be expressed by the following equation.

  According to Equation (4), the minimum value is obtained when d1 = d / 2. That is, when the diaphragm 30 is displaced by external vibration, the electrostatic energy becomes excessive, and the electrostatic energy is released at the stage where the restoring force returns to the original (displacement 0). In other words, charge movement occurs in the process in which the diaphragm 30 returns. Electricity can be charged by moving this electric charge to the battery 100.

Subsequently, a specific example of the power generation amount according to the present embodiment will be described.
First, Table 1 shows an example of specifications of the components of the electrostatic induction power generation device 1 in the present embodiment. The electrostatic induction power generation device shown in Table 1 represents the minimum one element as shown in FIG. 1, and when used as a power generation device, a plurality of one element is used depending on the required power generation amount. Used as an assembly arranged in an array.

  For example, when the planar size of one element is 20 μm × 20 μm and the planar size of the aggregate is 20 mm × 20 mm, if one element is arranged at an equal pitch, 100 × 100 = 10,000 aggregates may be formed. Is possible.

Using the specifications in Table 1, the power generation amount per vibration per element is calculated using Equation (4).
A power generation amount of 6.09 × 10 ⁻⁹ (J) is obtained. The power generation rate (W) of the entire power generation device as an aggregate can be calculated by the amount of power generation per vibration per element × frequency × number of elements. Therefore, when the vibration frequency of the diaphragm 30 is 10 (Hz) and the number of elements arranged in an array is 10,000, the power generation rate is 6.09 × 10 ⁻⁴ (W).

In Table 1, it was found that when the specifications other than the Gap dimension were made common, the power generation rate greatly fluctuated depending on the difference between the Gap dimensions (d1 and d2). Therefore, the relationship between the power generation rate and the gap size will be described.
FIG. 4 is a graph showing the relationship between the amplitude of the diaphragm and the power generation rate when the gap dimension is 25 nm, 50 nm, 100 nm, and 150 nm. The horizontal axis represents the amplitude (nm) of the diaphragm 30, and the vertical axis represents the power generation rate (W).

From FIG. 4, when the Gap dimension of the specifications shown in Table 1 is 50 nm, the power generation rate is approximately 1.0 × 10 ⁻⁴ (W), and the power generation rate increases as the Gap dimension decreases and the amplitude amount increases. It turns out that it becomes high. However, it is conceivable that the diaphragm 30 and the electret 60 and the diaphragm 30 and the electret 70 come into contact with each other when the gap size is reduced and the amplitude is increased. It is conceivable that when the diaphragm and the electret are in contact, the electrostatic force is maximized and the diaphragm is attracted by electrostatic attraction (electrostatic force) and does not return to the original state (displacement 0). Therefore, it is required that the elastic restoring force of the diaphragm be larger than the electrostatic force when the diaphragm abuts. Therefore, the relationship between the elastic restoring force and the electrostatic force will be described.

  FIG. 5 is a graph showing the relationship between the thickness of the diaphragm when the gap size is changed and the voltage (electret potential) necessary for holding the diaphragm in contact with the electret. Gap dimensions are 25 nm, 50 nm, and 100 nm. The horizontal axis represents the thickness (μm) of the diaphragm 30, and the vertical axis represents the voltage (V) required for contact and retention. From FIG. 5, it can be seen that as the thickness of the diaphragm 30 increases, the voltage required for holding contact increases.

  The Gap dimension of the specifications shown in Table 1 is 50 nm, and the thickness of the diaphragm 30 is 3 μm. The voltage required for contact holding under this condition is about 600 V, which is higher than the electret potential 500 V. Therefore, the diaphragm 30 is restored without being held in contact with the electret. Considering the same, it can be seen that the thickness of the diaphragm when the gap dimension is 25 nm is 5 μm, and the thickness of the diaphragm when the gap dimension is 100 nm is 1.7 μm.

  According to the configuration described above, since the diaphragm 30 vibrates in the vertical direction with respect to the electrets 60 and 70, it is necessary to form each of them into comb-like electrodes as in the prior art that vibrates in the horizontal direction. In addition, since the mutual opposing area (intersection area) and the gap dimension are the main elements that govern the amount of power generation, the structure and shape are simplified, and the respective dimensions can be easily managed. Therefore, the number of manufacturing steps can be reduced as compared with the prior art. Further, since the facing area is larger than that of the comb-like electrode, there is an effect that the power generation efficiency is increased.

  In addition, since the diaphragm 30 corresponding to the movable electrode of the prior art described above has elasticity, it is not necessary to form an elastic portion or an elastic member, and the structure can be simplified and the size can be reduced. In addition, it is possible to easily control vibration followability with respect to environmental vibration.

  Further, in the structure of the present embodiment, even if the diaphragm 30 and the electrets 60 and 70 are brought into contact with each other by vibration, there is no loss due to the contact itself becoming a load, and the contact surface is also worn. Few.

  In the present embodiment, the electret 60 and the electret 70 are disposed on both sides of the vibration direction of the diaphragm 30, but a structure in which either the electret 60 or the electret 70 is disposed can also be employed. However, since the diaphragm vibrates in the direction perpendicular to the electret, by providing electrets on both sides of the diaphragm in the vibration direction, the amount of power generation (power generation efficiency) is approximately twice that of the case where the diaphragm is disposed only on one side. Obtainable.

  Further, the closer the diaphragm 30 is to the electrets 60 and 70, the larger the power generation amount (power generation rate). However, when the diaphragm 30 is brought close to the electrets 60 and 70 as much as possible (that is, abuts), the diaphragm 30 may be adsorbed by an electrostatic force and vibration may be hindered. Therefore, by providing the insulating films 38 and 39 on the surfaces of the diaphragm 30 facing the electrets 60 and 70, the diaphragm 30 and the electrets 60 and 70 are not in direct contact with each other, and the gap corresponding to the thickness of the insulating film is eliminated. Therefore, the influence of the electrostatic force on the vibration can be reduced. In other words, since the amount of displacement of the diaphragm can be increased within a range where the diaphragm and the electret do not directly contact, the power generation efficiency can be increased. Furthermore, if the insulating films 38 and 39 are made of the same material, charging due to contact can be prevented.

  Moreover, the damping phenomenon can be suppressed by increasing the internal pressure of the case members (the upper case 10 and the lower case 20) to be lower than the atmospheric pressure, and the vibration efficiency can be increased. Therefore, it is more preferable to reduce the pressure inside the case member to a vacuum or a state close to vacuum.

  Further, when the diaphragm 30 abuts on the electrets 60 and 70 due to vibration, the restoring elastic force of the diaphragm is made larger than the adsorption force by the electrostatic force between the diaphragm 30 and the electrets 60 and 70. Even if the diaphragm 30 is attracted by the electrostatic force, the suction is released by the restoring elastic force, so that the diaphragm 30 can vibrate following the environmental vibration.

  In addition, the electrostatic induction power generation device 1 of the present embodiment is a power generation device in which the configuration of the diaphragm 30 and the electrets 60 and 70 is one element, and a plurality of these elements are arranged in an array. Therefore, an electrostatic induction power generation device having a large power generation amount as a single element can be realized.

  Further, the diaphragm 30 and the electrets 60 and 70 are subjected to high-temperature vacuum treatment to remove moisture on the surface before being sealed and fixed by the case member. By doing in this way, when diaphragm 30 and electrets 60 and 70 contact, both can be prevented from being adsorbed by moisture.

In addition, if the displacement amount of the diaphragm 30 is increased, the power generation amount (power generation rate) can be increased. Therefore, a region having a lower rigidity than the central portion is formed in the connecting portion between the fixed portion of the peripheral portion of the diaphragm 30 and the central portion facing the electrets 60 and 70 (the portion constituting the facing area). The shape of the diaphragm 30 that increases the displacement amount is proposed as a modified example.
(Modification 1)

First, Modification 1 will be described with reference to the drawings. In the first embodiment described above, the shape of the diaphragm 30 is a rectangle having the same thickness, whereas the first modification is characterized in that a thin portion is formed between the fixed portion and the central portion. Have. The configuration other than the diaphragm 30 is the same as the configuration shown in FIG.
FIG. 6 is a cross-sectional view showing an electrostatic induction power generating device according to the first modification. The diaphragm 30 has a thin portion 33 formed at a connection portion between a fixed portion joined by the upper case 10 and the lower case 20 and a central portion 36 as an opposing portion of the electrets 60 and 70. The thin portion 33 is less rigid than the other portions. That is, it becomes easy to elastically deform.
(Modification 2)

Subsequently, Modification 2 will be described with reference to the drawings. Modification 2 is characterized in that the fixed portion and the central portion are connected by a beam. The configuration other than the diaphragm 30 is the same as the configuration shown in FIG.
FIG. 7 is a plan view showing an electrostatic induction power generating device according to the second modification. A state in which the upper case 10 is seen through is shown.

  The diaphragm 30 is connected between the fixed portion 34 joined by the upper case 10 and the lower case 20 and the central portion 36 as an opposing portion of the electrets 60 and 70 by four beams 35a to 35d. . Each of the beams 35a to 35d extends radially from the four corners of the central portion 36 with the same dimensions, and is formed such that the center of the central portion 36 is the center of gravity. The beams 35a to 35d have the same thickness as the central portion 36. Moreover, it is desirable that the electrets 60 and 70 be larger than the plane area of the central portion 36.

With the configuration as in the first and second modifications described above, the diaphragm 30 can easily follow environmental vibrations, and the central portion 36 hardly deforms. Therefore, the diaphragm 30 and the electrets 60 and 70 are opposed to each other. Since the surfaces can be maintained in a parallel state, a certain facing area can be ensured during vibration, so that power generation efficiency can be increased.
(Modification 3)

Next, Modification 3 will be described with reference to the drawings. Modification 3 is characterized in that a weight portion is formed in the central portion facing the electrets 60 and 70. Since the configuration other than the diaphragm 30 is the same as that in FIG.
8A and 8B show an electrostatic induction power generating device according to Modification Example 3. FIG. 8A is a plan view and FIG. 8B is a cross-sectional view taken along the line AA in FIG. Note that (a) is illustrated through the upper case 10. 8A and 8B, a weight portion 37 is formed at the central portion of the diaphragm 30 that faces the electret 60.

  The weight portion 37 includes a fixed portion 34 joined by the upper case 10 and the lower case 20 of the diaphragm raw material thicker than that of the first embodiment (see FIG. 1), and an opposing portion of the electrets 60 and 70. A region to be connected is formed by thin processing from the upper case 10 side. And this thin part is the beams 35a-35d extended radially from the four corners of the weight part 37, and is formed so that the center of the weight part 37 may become a gravity center. The thicknesses of the beams 35a to 35d are set to the same level as that of the second modification (see FIG. 7). An insulating film 38 is formed on the surface of the weight portion 37 facing the electret 60, and an insulating film 39 is formed on the surface facing the electret 70.

  Note that the thinning of the beams 35a to 35d may be performed from the lower case 20 side. If the beams 35a to 35d are processed with equal dimensions from the upper case 10 side and the lower case 20 side, there is an advantage that the vertical vibration of the diaphragm 30 can be balanced. Have. Further, it is desirable that the plane area of the electrets 60 and 70 is larger than the plane area of the weight portion 37. Moreover, the structure which makes the thickness of the fixing | fixed part 34 of the diaphragm 30 the same as the beams 35a-35d may be sufficient. Further, the gap dimension (gap dimension) between the weight portion 37 and the electret 60 and the electret 70 is equal, and an insulating film is formed on the surface of the weight portion 37 facing the electret.

  By providing the weight portion 37 on the diaphragm 30 as described above, the displacement amount of the diaphragm 30 can be increased, so that the power generation efficiency can be increased.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, the shape of the opposed surfaces of the electrets 60 and 70 and the diaphragm 30 is not limited to a quadrangle, and may be a circle or a polygon. In addition, a plurality of one element as a power generation device is arranged in an array to form an assembly of electrostatic induction power generation devices, but may be an assembly of stacks.
Further, the configuration described above can be applied not only to a power generation device but also to a mechanoelectric conversion element or an electrostatic induction conversion element that detects environmental vibration.

  DESCRIPTION OF SYMBOLS 1 ... Electrostatic induction power generation device, 10 ... Upper case, 20 ... Lower case, 30 ... Diaphragm which is a movable electrode, 38, 39 ... Insulating film, 40 ... Upper electrode, 50 ... Lower electrode, 60, 70 ... Electret.

Claims (8)

Electrets,
A diaphragm that is provided so as to face the electret with a gap, and the entire periphery or a part of the peripheral edge is fixed, and the diaphragm vibrates in a direction perpendicular to the electret;
A case member for storing the electret and the diaphragm;
An electrostatic induction power generation device comprising: The electrostatic induction power generating device according to claim 1,
The electrostatic induction power generation device, wherein the electret is disposed on both sides of the vibration direction of the diaphragm. The electrostatic induction power generation device according to claim 1 or 2,
An electrostatic induction power generating device, wherein an insulating film is provided on at least a surface of the diaphragm facing the electret. The electrostatic induction power generating device according to claim 1,
An electrostatic induction power generation device, wherein an internal pressure of the case member is reduced from an atmospheric pressure. In the electrostatic induction power generation device according to any one of claims 1 to 4,
An electrostatic induction power generation device, wherein a restoring elastic force of the diaphragm when the diaphragm comes into contact with the electret by vibration is larger than an adsorption force due to static electricity between the diaphragm and the electret. The electrostatic induction power generating device according to claim 1,
The electrostatic induction power generating device, wherein the diaphragm has a region having a smaller rigidity than the central portion between a fixed portion of a peripheral portion and a central portion facing the electret. The electrostatic induction power generation device according to any one of claims 1 to 6,
An electrostatic induction power generation device, wherein a weight portion is formed at a central portion of the diaphragm facing the electret. The electrostatic induction power generating device according to any one of claims 1 to 7,
An electrostatic induction power generation device, wherein a plurality of the diaphragms and the electrets are arranged in an array.

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