JPH04275077A - Microactuator - Google Patents

Abstract

PURPOSE:To eliminate formation of electric wiring or electrodes for power supply on a substrate by employing magnetic force to be generated when a magnetic pole board is irradiated with a circularly polarized laser beam. CONSTITUTION:Magnetic pole plates 7a-7f and 6a-6f of a stator 2 and a rotor 3 are irradiated on the transparent glass substrate side thereof, in one and one correspondence, with a circularly polarized laser beam 28 projected from a laser beam irradiating means 20 and they form magnetic field generating means, respectively. Free electrons on the thin copper film of the magnetic pole plate irradiated with the circularly polarized laser beam move in the rotational direction of the circularly polarized light to produce a rotating current which then induces a magnetic field. Consequently, the polarity of the stator 2 is fixed and the polarity of each magnetic pole plate in the rotor 3 is varied by controlling the rotational direction of the circularly polarized light thus rotating the rotor.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microactuator formed on a substrate, and more particularly to a structure of a microactuator that uses magnetic force for driving force.

0002

[Background Art] In recent years, the development of semiconductor circuits has been remarkable.
There is a growing demand for advanced systems that can be miniaturized by integrating sensors, actuators, etc. onto the semiconductor substrates that make up conventional electronic circuits.

The advantage of this ultra-miniaturization is: ■ It can be manufactured using the same etching and lithography as LSI etc. ■ At this time, the entire mechanism is manufactured in an assembled state, and it is possible to manufacture with high precision, so it is easy to make adjustments. ■It can be manufactured in the semiconductor manufacturing process, so it can be fabricated on the same substrate as the logic circuit sensor.■It does not take up much space and can be used in minute places where conventional machines, especially robots, could not be used. It will be done.

[0004] The driving force of a microactuator formed on a semiconductor substrate includes electrostatic force, thermal expansion force, and superelectric force, but electrostatic force is generally used.

The reason for this is that the mass of an object is proportional to the cube of its dimensions, and the electrostatic force between electrodes is proportional to the square of its dimensions; therefore, the electrostatic force per unit mass is inversely proportional to its dimensions, and increases as it becomes smaller.

A microactuator that uses electrostatic force for driving force in this way is called an electrostatic microactuator.

An electrostatic motor, which is an example of a conventional electrostatic microactuator, will be described below with reference to FIGS. 9 and 1.
This will be explained with reference to 0.

The conventional electrostatic motor 50 is made of silicon (Si).
) A silicon dioxide (SiO2) layer 52 and a trisilicon tetranitride (Si3 N4) layer 53 are formed on a substrate 51, and a first polycrystalline silicon (Si) layer 54 is formed thereon as a reference layer.

Next, a rotor 55 and a stator 56 are formed concentrically from a second polycrystalline silicon (Si) layer.

The rotor 55 has a cross-like shape and is rotatably supported by a central shaft 58 made of a third layer of polycrystalline silicon (Si), and its tip portion forms an electrode 55a.

The stator 56 is arranged in 12 sections on the outer circumference of the rotating region of the rotor 55, and has electrodes 56a and 56b.
- It has a diameter of 56c, and its diameter is as small as 100 μm.

The electrodes 56a, 56b, and 56c are connected in parallel every three, and the electrostatic motor 50 has three phases and four
The poles form an electrostatic motor. Furthermore, a film 60 of trisilicon tetranitride (Si3 N4) is provided at the contact portion of the rotor 55 with the central shaft 58 in order to reduce friction of the rotor 55.

The operation of the electrostatic motor 50 having the above configuration will be explained as follows based on FIG.

First, referring to state (a) in FIG. 11, a voltage of 60 to 400 V is applied between the electrode 55a of the rotor 55 and the electrode 56a of the stator 56. As a result, the electrode 5
Electrostatic attraction acts between 5a and electrode 56a. At this time, the rotor 55 is stationary.

Next, referring to state (b) in FIG. 11, a voltage is applied between the electrode 55a of the rotor 55 and the electrode 56b of the stator 56. By this, the electrode 55a and the electrode 56
An electrostatic attraction is exerted during the period b, and the rotor 55 moves clockwise.

Next, referring to state (c) in FIG. 11, a voltage is applied between the electrode 55a of the rotor 55 and the electrode 56c of the stator 56. By this, the electrode 55a and the electrode 56
During time c, electrostatic attraction acts, and the rotor 55 moves clockwise.

As described above, by sequentially applying voltage to the electrode portions 56a, 56b, and 56c of the stator 56, the rotor 55 rotates.

[0018] In this way, conventional electrostatic motors perform rotational motion using electrostatic attraction.

[0019]

However, the electrostatic motor having the above structure obtains driving energy by supplying power from the outside through electric wiring and electrodes. As a result, the fixed electrodes are electrically coupled to each other via the silicon (Si) substrate to form a large capacitor.

[0020] Due to the formation of this large capacity capacitor, more than 98% of the power supplied from the outside is consumed by this large capacity capacitor, making it extremely difficult to increase drive efficiency. Here, drive efficiency refers to "power contributing to drive"/"power supplied from outside."

[0021] Furthermore, 50% of the element area of this electrostatic motor
Since the nearby area is covered with electrical wiring and electrodes, the effective area ratio is low, which poses a problem in miniaturizing electrostatic motors. Here, the effective area ratio refers to "area of component elements involved in actual driving"/"area of elements of the entire electrostatic motor."

These problems are not limited to electrostatic motors, but are problems of all electrostatic microactuators.

The present invention was made in order to solve the above-mentioned problems, and provides a microactuator that can increase the driving efficiency and effective area ratio of the microactuator formed on a substrate. purpose.

[0024]

[Means for Solving the Problems] In order to solve the above-mentioned problems, a microactuator based on the invention according to claim 1 has a thin film made of a conductive non-magnetic material on a substrate through which a laser beam passes. By irradiating the magnetic pole plate with a laser beam emitted by the laser beam irradiation means, , a first magnetic field generating means for generating a magnetic field by a rotating current consisting of a real current generated on a thin film according to rotational propagation of circularly polarized light of the laser beam; and a first magnetic field generating means disposed opposite to the first magnetic field generating means; A second magnetic field generating means generates a predetermined magnetic field corresponding to the magnetic field generated by the first magnetic field generating means, and a force generated between the magnetic fields generated by each of the first magnetic field generating means and the second magnetic field generating means magnetic field generating means and a second
and magnetic field control means for generating a predetermined relative driving force between the magnetic field generating means and the magnetic field generating means.

In the microactuator according to the second aspect of the invention, in the microactuator according to the first aspect, the second magnetic field generating means has the same configuration as the first magnetic field generating means.

A microactuator based on the invention set forth in claim 3 is the microactuator set forth in claim 2, wherein the second magnetic field generating means generates a predetermined magnetic field using an electromagnet or a permanent magnet.

[0027]

According to the present invention, by using the magnetic force generated by irradiating the magnetic pole plate with circularly polarized laser light, there is no need for electrical wiring or electrodes for power supply on the substrate.

[0028]

[Example] Hereinafter, a micromotor, which is a first example of a microactuator based on the present invention, will be explained.
This will be explained with reference to FIGS. 1 to 5.

The micromotor 10 in this embodiment includes a magnetic pole base 1 and a laser beam irradiation means 20 having circularly polarized light.
It consists of

The magnetic pole base 1 is shown in FIGS. 1 to 2(a) and (b).
), it is composed of a stator 2 and a rotor 3. The stator 2 has a substantially fan-shaped copper thin film made of a non-magnetic material on a glass substrate 4 made of transparent glass, which is a material that allows laser light to pass through with low loss and has a small coefficient of thermal expansion. The copper thin films and glass substrates 4 are arranged radially at a predetermined pitch, and the respective copper thin films and glass substrates 4 are arranged on the magnetic pole plate 7.
a to 7f are formed.

Referring to FIG. 2(b), the rotor 3 includes magnetic pole plates 6a, 6b, 6c, 6d, 6e, and 6 having the same shape as the copper thin film.
f are arranged radially around the pin joint 11 in the same manner as the magnetic pole plates 7a to 7f, and the pin joint 11
It is possible to rotate around the center. Further, the diameter of the rotor 3 is 10 μm in this embodiment.

The magnetic pole plates 6a-6f are formed by depositing copper thin films 8a-8f on transparent glass substrates 9a-9f, respectively, and the copper thin films 8a-8f are arranged on the stator side.

The laser beam irradiation means 20 having circularly polarized light is
Referring to FIG. 3, it is composed of a laser light source 21, a polarizer 23, an optical phase modulator 25, and an optical lens 27. The operation of this laser beam irradiation means 20 is roughly as follows.

First, a laser beam 22 is generated by a laser light source 21 using a semiconductor laser, a gas laser, or the like. The linearly polarized wave is extracted from the laser beam 22 by a polarizer 23 and becomes a laser beam 24 having linearly polarized wave. The laser beam 24 having linear polarization becomes a laser beam 28 having clockwise or counterclockwise circular polarization depending on the information in the optical phase modulator 25 using an electro-optic effect or a magneto-optic effect. The circularly polarized laser beam 28 is used in a condensing system such as an optical lens 27 to form a beam spot system of several μm to several hundred μm to irradiate the object to be apertured.

In this embodiment, the circularly polarized laser beam 28 is irradiated from the transparent glass substrates 9a to 9f sides of the magnetic pole plates 7a to 7f of the stator 2 and the magnetic pole plates 6a to 6f of the rotor 3 in a one-to-one ratio. and each forms a magnetic field generating means.

Next, the principle of the magnetic field generating means when a circularly polarized laser beam is irradiated onto the magnetic pole plate will be explained with reference to FIG.

Free electrons on the copper thin film of the magnetic plate irradiated with circularly polarized laser light move in accordance with the rotating direction of the circularly polarized light, and a rotating current consisting of an actual current is generated. FIG. 4A shows a case where the magnetic pole plate is irradiated with a laser beam 28R having clockwise circular polarization from the glass substrate side. in this case,
A clockwise rotating current is generated on the copper thin film, and a magnetic field H1 is generated in the laser beam irradiation direction. At this time, the copper thin film side becomes the north pole, and the glass substrate side becomes the south pole. Therefore, when the magnetic pole plate is irradiated with the laser beam 28L having counterclockwise circularly polarized light from the glass substrate side, a magnetic field H2 is generated in the opposite direction to the laser beam irradiation direction as shown in FIG. The thin film side becomes the S pole, and the glass substrate side becomes the N pole.

The operation of the micromotor 10 in this embodiment to which the above configuration and principle are applied will be explained with reference to FIG. The polarities shown in FIG. 5 each indicate the polarity on the copper thin film side. Therefore, when the polarity of the magnetic pole plate 6a is N pole and the polarity of magnetic pole plate 7a is S pole, the magnetic pole plate 6a and the magnetic pole plate 7a
There will be an attraction between them.

Referring to FIG. 5, in state I, stator 2
The polarity on the copper thin film side of each magnetic pole plate 7a to 7f is 7a, 7c.
, 7e are controlled to be north poles, and 7b, 7d, and 7f are controlled to be south poles.

Furthermore, the polarity of each of the magnetic pole plates 6a to 6f of the rotor 3 on the copper thin film side is such that 6a, 6c, and 6e are N poles, 6b, 6e, and
6f is controlled to the south pole.

In this state I, when the rotor 3 has a magnetic pole plate 6a, a repulsive force is generated between the rotor 3 and the magnetic pole plate 7a of the stator 2, and an attractive force is generated between the rotor 3 and the magnetic pole plate 7b of the stator 2. do. As a result, a force that moves the magnetic pole plate 6a of the rotor 3 in a clockwise direction is applied. At this time, the other magnetic pole plates 6b, 6c
, 6d, 6e, and 6f, similar forces act on them, causing the rotor 3 to move clockwise.

Next, when the rotor 3 moves to the state II position, the polarity of each magnetic pole plate of the rotor 3 is reversed by controlling the laser beam. In other words, the magnetic pole plates 6a, 6c, and 6e of the rotor 3 are S poles, and the magnetic pole plates 6b, 6d, and 6f are N poles.
Become the pole. As a result, a repulsive force acts between the stator 4 and each magnetic pole plate of the rotor 3. Therefore, the rotor 3 continues to move clockwise.

[0043] If the rotor 3 then moves to state III, this state III is the same as state I described above. The rotor 3 thus continues to move clockwise.

In this way, the polarity of the stator is fixed,
The polarity of each magnetic pole plate of the rotor is changed by controlling circularly polarized laser light, and the rotor performs rotational motion due to the attractive and repulsive forces generated between the stator and each magnetic pole plate of the rotor.

It goes without saying that, contrary to the above embodiment, the same effects as described above can be obtained by changing the magnetism of the magnetic pole plates of the stator and fixing the polarity of the magnetic pole plates of the rotor.

Further, in the above embodiment, the same effect can be obtained even if a magnetic body is used instead of using a magnetic field generating means on the fixed polarity side of the magnetic pole plate on either the stator side or the rotor side. Needless to say.

It goes without saying that the same effect can be obtained by controlling and changing the polarity of both the stator and the rotor. Further, it goes without saying that the direction of rotation is not limited to clockwise, but can be controlled to rotate counterclockwise.

Further, the number of magnetic pole plates is not limited to six each, as long as the number of rotors and stators is the same and is an even number.

As a result of the above, this embodiment eliminates the need for electrical wiring and electrodes on the substrate, making it possible to reduce the element area to 1/10 of that of the conventional device, and reducing power consumption that does not contribute to driving. This makes it possible to save energy by reducing the driving voltage to 1/10 that of the conventional method.

Next, a microspring, which is a second embodiment of the microactuator based on the present invention, will be described with reference to FIGS. 6 and 7.

Microspring 4 in this embodiment
0 is composed of a magnetic pole base 41 and a laser beam irradiation means 20 having circularly polarized light. Here, the laser beam irradiation means 20 is equivalent to the laser beam irradiation means 20 described in the first embodiment.

The magnetic pole base 41 is composed of a fixed base 42 and a movable element 43. The fixing base 42 has a concave cross-sectional shape and is made of transparent glass 42(a), which is a material that allows laser light to pass through with low loss and has a small coefficient of thermal expansion. Further, a copper thin film 42(b) made of a non-magnetic material is formed on the bottom of the inner surface of the fixing base 42, and forms a magnetic pole plate.

Next, the mover 43 has a thin cylindrical shape,
It has a glass substrate 43(a) made of transparent glass, which is a material that allows laser light to pass through with low loss and has a small coefficient of thermal expansion.
It is supported by a fixed base 42 by a glass spring 45 so as to be movable in a direction perpendicular to the plane.

Furthermore, the glass substrate 43(a) of the mover 43
A copper thin film 43(b) is formed on the fixed base 42 side of the magnetic pole plate 43(b) to form a magnetic pole plate.

In the above, the fixed base 42, the laser beam irradiation means 20, the movable element 43 and the laser beam irradiation means 20 each form a magnetic field generation means.

Next, when the magnetic pole plate is irradiated with a circularly polarized laser beam, a magnetic field is generated based on the same principle as shown in the first embodiment.

Next, the operation of this embodiment will be explained with reference to FIG. FIG. 8(a) shows a laser beam 2 having clockwise circular polarization applied to the movable element 43 from the glass substrate 43(a) side.
8R, and the fixing table 42 is irradiated with a clockwise circularly polarized laser beam 28R from the glass substrate 42(a) side. At this time, the copper thin film 43 of the mover 43
The (b) side is the N pole, and the copper thin film 42 of the fixed base 42 (b) side is the N pole.
As a pole, a repulsive force is generated between the fixed base 42 and the movable element 43. This repulsive force causes the mover 43 to move upward in the figure.

Also, referring to FIG. 8(b), the above-mentioned FIG.
In (a), if the laser beam 28L having counterclockwise circular polarization is irradiated from the glass substrate 42(a) side of the fixed base 42, the copper thin film 42b side of the fixed base 42 becomes the S pole, and the position between the fixed base 42 and the movable element 43 becomes There is an attraction between them.

By controlling the polarities of the stationary table and the movable element using circularly polarized laser light in this manner, the movable element can be vibrated up and down.

It goes without saying that the same effects can be obtained even if one of the above embodiments is implemented using another magnetic material without using the magnetic field generating means.

[0061]

As described above, according to the invention as set forth in claim 1, there is provided a magnetic pole plate in which a thin film made of a conductive non-magnetic material is formed on a substrate through which a laser beam passes; By irradiating the laser beam emitted from the laser beam irradiation means to the laser beam irradiation means that generates and irradiates a laser beam having circularly polarized light in the circular direction or the counterclockwise direction, and the magnetic pole plate, the circularly polarized light of the laser beam is transmitted according to the rotational propagation. , a first magnetic field generating means that generates a magnetic field by a rotating current consisting of an actual current generated on the thin film, and a predetermined magnetic field generating means arranged opposite to the first magnetic field generating means and corresponding to the magnetic field generated by the first magnetic field generating means. The second magnetic field generating means generates a magnetic field, and the force generated between the magnetic fields generated by each of the first magnetic field generating means and the second magnetic field generating means causes the first magnetic field generating means and the second magnetic field generating means to generate a magnetic field. and magnetic field control means for generating a predetermined relative driving force between the magnetic field control means and the magnetic field control means.

[0062] Therefore, by using repulsion and attraction due to the magnetic force generated between the magnetic pole plates as a driving source, there is no need for electric wiring or electrodes for power supply on the substrate. This makes it possible to increase drive efficiency and increase the effective area ratio, making it possible to realize miniaturization, energy saving, and high performance of microactuators. Furthermore, by being able to supply energy spatially, it becomes possible to create a microactuator with a high degree of design freedom in which the power supply and actuator are independent.

According to the invention described in claim 2, claim 1
In the microactuator described in , the second magnetic field generating means has the same configuration as the first magnetic field generating means.

[0064] Therefore, by using repulsion and attraction due to the magnetic force generated between the magnetic pole plates as a driving source, there is no need for electrical wiring or electrodes for power supply on the substrate. This makes it possible to increase drive efficiency and increase the effective area ratio, making it possible to realize miniaturization, energy saving, and high performance of microactuators. Furthermore, by being able to supply energy spatially, it becomes possible to create a microactuator with a high degree of design freedom in which the power supply and actuator are independent.

According to the invention recited in claim 3, claim 2
In the microactuator described in , the second magnetic field generating means generates a predetermined magnetic field using an electromagnet or a permanent magnet.

[0066] Therefore, by using the repulsive force and attractive force due to the magnetic force generated between the magnetic pole plates as the driving source, there is no need for electric wiring or electrodes for power supply on the substrate. This makes it possible to increase drive efficiency and increase the effective area ratio, making it possible to realize miniaturization, energy saving, and high performance of microactuators. Also,
By being able to supply energy spatially, it becomes possible to create a microactuator with a high degree of design freedom in which the power supply and actuator are independent.

[Brief explanation of the drawing]

FIG. 1 is an overall perspective view of a micromotor in a first embodiment based on the present invention.

FIG. 2(a) is an end view taken along the line X--X in FIG. 1; (b) is an overall perspective view of the rotor.

FIG. 3 is a schematic configuration diagram of a laser beam irradiation means in a first embodiment based on the present invention.

FIG. 4 is a schematic diagram when a magnetic pole plate is irradiated with a laser beam having circularly polarized light.

FIG. 5 is a schematic diagram showing the principle of rotation of a micromotor in a first embodiment based on the present invention.

FIG. 6 is an overall perspective view of a microspring in a second embodiment based on the present invention.

FIG. 7 is a sectional view of a spring in a second embodiment based on the invention.

FIG. 8 is a schematic diagram when a microspring in a second embodiment based on the present invention is irradiated with a laser beam having circularly polarized light.

FIG. 9 is an overall perspective view of a micromotor in the prior art.

10 is a sectional view taken along the line YY in FIG. 9; FIG.

FIG. 11 is a schematic diagram showing the principle of rotation of a micromotor in the prior art.

[Explanation of symbols]

10 Micromotor 40 Microspring 1, 41 Magnetic pole stand 20 Laser beam irradiation means 2 Stator 3 Rotor 8 Pin joint 4, 9a, 9b, 9c, 9d, 9e, 9f Transparent glass substrate 8a, 8b, 8c, 8d, 8e ,8f Copper thin film 6
a, 6b, 6c, 6d, 6e, 6f, 7a, 7b, 7c
, 7d, 7e, 7f Magnetic pole plate 28 Laser beam 28R with circular polarization Laser beam 28L with clockwise circular polarization
A laser beam 42 having counterclockwise circular polarization, a fixed base 43, a movable element 45, a glass spring, and the same reference numerals in the drawings indicate the same contents or corresponding parts.

Claims (3)

[Claims] 1. A magnetic pole plate formed by forming a thin film made of a conductive non-magnetic material on a substrate through which laser light passes;
A laser beam irradiating means for generating and irradiating a laser beam having clockwise or counterclockwise circularly polarized light; and a circularly polarized laser beam by irradiating the magnetic pole plate with the laser beam emitted by the laser beam irradiating means. a first magnetic field generating means that generates a magnetic field by a rotating current consisting of an actual current generated on the thin film in accordance with a rotating electric field; The first magnetic field is generated by a second magnetic field generating means that generates a corresponding predetermined magnetic field, and a force generated between the magnetic fields generated by each of the first magnetic field generating means and the second magnetic field generating means. A microactuator comprising: magnetic field control means for generating a predetermined relative driving force between the means and the second magnetic field generating means. 2. The second magnetic field generating means includes the first magnetic field generating means.
2. The microactuator according to claim 1, having a configuration similar to that of the magnetic field generating means. 3. The microactuator according to claim 2, wherein the second magnetic field generating means generates a predetermined magnetic field using an electromagnet or a permanent magnet.