JP2652086B2 - Micro actuator - Google Patents

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 using a magnetic force as a driving force.

[0002]

2. Description of the Related Art In recent years, the development of semiconductor circuits has been remarkable.
There has been a demand for an advanced system that integrates sensors, actuators, and the like on a semiconductor substrate that constitutes a conventional electronic circuit and that is miniaturized.

The advantage of this ultra-miniaturization is that it can be manufactured by the same etching and lithography as LSI and the like. At this time, the entire mechanism is manufactured in an assembled state, and since it can be manufactured with high precision, no adjustment is required. Because it can be manufactured in a certain semiconductor manufacturing process, it can be used on a conventional machine, especially in a minute place where a robot cannot be used.

The driving force of the microactuator formed on the semiconductor substrate includes an electrostatic force, a thermal expansion force, and a super-electrical force. Generally, the electrostatic force is used.

[0005] The reason is that the mass of an object is proportional to the cube of the size and the electrostatic force between the electrodes is proportional to the square, so that the electrostatic force per unit mass is inversely proportional to the size and increases as the size decreases.

As described above, a microactuator using an electrostatic force as a driving force is called an electrostatic microactuator.

FIGS. 9 and 1 show an electrostatic motor which is an embodiment of a conventional electrostatic microactuator.
0 will be described.

The conventional electrostatic motor 50 is made of silicon (S
i) Silicon dioxide (SiO 2) _Two) Layer 52, tetranitride
Trisilicon (Si_ThreeN_Four) Forming layer 53, on which reference
A first polycrystalline silicon (Si) layer 54 is formed as a layer.
ing.

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

The rotor 55 has a cross shape, is rotatably supported by a central shaft 58 made of a third polycrystalline silicon (Si) layer, and has a distal end forming an electrode 55a.

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

The electrodes 56a, 56b and 56c are respectively
Each three are connected in parallel, and the electrostatic motor 50
It forms a pole electrostatic motor. Also, in the rotor 55
The contact portion with the mandrel 58 reduces friction of the rotor 55.
Trisilicon tetranitride (Si_ThreeN _Four) Is provided.
You.

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

First, referring to the state (a) of 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. This allows the electrode 5
An electrostatic attractive force acts between the electrode 5a and the electrode 56a. At this time, the rotor 55 is stationary.

Next, referring to the state (b) of FIG. 11, a voltage is applied between the electrode 55a of the rotor 55 and the electrode 56b of the stator 56. As a result, the electrode 55a and the electrode 56
The electrostatic attraction acts during the period b, and the rotor 55 moves clockwise.

Next, referring to the state (c) of FIG. 11, a voltage is applied between the electrode 55a of the rotor 55 and the electrode 56c of the stator 56. As a result, the electrode 55a and the electrode 56
The electrostatic attraction acts during the period c, and the rotor 55 moves clockwise.

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

As described above, the conventional electrostatic motor performs the rotary motion using the electrostatic attraction.

[0019]

However, in the electrostatic motor having the above structure, electric power is supplied from outside through electric wires and electrodes to obtain driving energy. Thus, the fixed electrodes are electrically coupled to each other via the silicon (Si) substrate to form a large-capacity capacitor.

By forming this large-capacity capacitor, 98% or more of the power supplied from the outside is consumed by this large-capacity capacitor, and it is very difficult to increase the driving efficiency. Here, the driving efficiency refers to “power contributing to driving” / “power supplied from outside”.

Also, 50% of the element area of this electrostatic motor
Since the vicinity is accommodated by electric wiring and electrodes, the effective area ratio is low, which has been a problem in miniaturizing the electrostatic motor. Here, the effective area ratio means “area of components and elements involved in actual driving” / “element area of entire electrostatic motor”.

These problems are not limited to the electrostatic motor but also to the entire electrostatic microactuator.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a microactuator capable of increasing the driving efficiency and the effective area ratio of a microactuator formed on a substrate. Aim.

[0024]

According to a first aspect of the present invention, there is provided a microactuator comprising: a thin film made of a conductive non-magnetic material on a substrate through which a laser beam is transmitted; By irradiating the laser light emitted by the laser light irradiating means to the magnetic pole plate, laser light irradiating means for generating and irradiating laser light having clockwise or counterclockwise circularly polarized light, A first magnetic field generating means for generating a magnetic field by a rotating current consisting of an actual current generated on a thin film in accordance with the rotational propagation of circularly polarized laser light; and a first magnetic field generating means disposed opposite to the first magnetic field generating means. A second magnetic field generating means for generating a predetermined magnetic field corresponding to the magnetic field generated by the means, and a magnetic field generated between the first magnetic field generating means and the magnetic field generated by the second magnetic field generating means. Accordingly, the first magnetic field generating means and the second
Magnetic field control means for generating a predetermined relative driving force between the magnetic field generation means and the magnetic field generation means.

According to a second aspect of the present invention, in the microactuator according to the first aspect, the second magnetic field generating means has a configuration similar to that of the first magnetic field generating means.

According to a third aspect of the present invention, in the microactuator according to the second aspect, 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 a laser beam having circularly polarized light, electric wiring and electrodes for power supply are not required on the substrate.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a micromotor as a first embodiment of a microactuator according to the present invention will be described.
This will be described with reference to FIGS.

The micromotor 10 in this embodiment
Is a magnetic pole table 1 and a laser beam irradiation means 2 having circularly polarized light.
0.

The magnetic pole table 1 is shown in FIGS.
Referring to (b), it is composed of a stator 2 and a rotor 3. The stator 2 allows a laser beam to pass therethrough with low loss, and a substantially fan-shaped copper thin film made of a nonmagnetic material is formed on a glass substrate 4 made of a transparent glass that is a material having a small thermal expansion coefficient.
The copper thin film and the glass substrate 4 are arranged and formed radially around the pin joint 11 at a predetermined pitch, and form magnetic pole plates 7a to 7f.

Referring to FIG. 2B, rotor 3 has pole plates 6a, 6b, 6c, 6d, 6e, and 6 having the same shape as the copper thin film.
f are formed radially around the pin joint 11 in the same manner as the magnetic pole plates 7a to 7f.
Can be rotated around. The rotor 3 has a diameter of 10 μm in this embodiment.

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

The laser light irradiation means 20 having circularly polarized light
Referring to FIG. 3, the optical system includes 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 light 22 is generated by a laser light source 21 using a semiconductor laser or a gas laser. The laser beam 22 is taken out of the linearly polarized light by the polarizer 23 and becomes a laser beam 24 having a linearly polarized wave. The laser light 24 having the linearly polarized light becomes a laser light 28 having a clockwise or counterclockwise circularly polarized light according to information in the optical phase modulator 25 using the electro-optic effect or the magneto-optic effect. The laser light 28 having circularly polarized light forms an irradiation light on an object to be converged in a beam spot system of several μm to several hundred μm in a condensing system such as the optical lens 27.

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

Next, the principle of the magnetic field generating means when the magnetic pole plate is irradiated with laser light having circular polarization will be described with reference to FIG.

The free electrons on the copper thin film of the magnetic plate irradiated with the circularly polarized laser light move in the direction of rotation of the circularly polarized light to generate a rotating current composed of an actual current. FIG. 4 (a)
Shows a case where the magnetic pole plate is irradiated with a laser beam 28R having circularly polarized light clockwise 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 light irradiation direction. At this time, the copper thin film side is N
The pole and the glass substrate side become the S pole. Therefore, when the magnetic pole plate is irradiated with the laser light 28L having the circularly polarized light counterclockwise from the glass substrate side, a magnetic field H2 is generated in a direction opposite to the laser light irradiation direction as shown in FIG. The thin film side has an S pole, and the glass substrate side has an N pole.

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

Referring to FIG. 5, in state I, stator 2
The polarity of the magnetic pole plates 7a to 7f on the copper thin film side is 7a, 7
c and 7e are controlled to the N pole, and 7b, 7d and 7f are controlled to the S pole.

The polarities of the magnetic pole plates 6a to 6f of the rotor 3 on the copper thin film side are 6a, 6c, 6e, N poles, 6b, 6e,
6f is controlled to the south pole.

In this state I, when the rotor 3 is the 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. I do.
Thus, a clockwise moving force acts on the magnetic pole plate 6a of the rotor 3. At this time, the other magnetic pole plates 6b, 6
A similar force acts on c, 6d, 6e, and 6f, and the rotor 3 moves clockwise.

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

Next, when the rotor 3 moves to the state III, this state III is the same as the state I described above.
Therefore, the rotor 3 continues to move clockwise.

Thus, the polarity of the stator is fixed,
The polarity of each magnetic pole plate of the rotor is changed by controlling a laser beam having circular polarization, and the rotor performs a rotational motion by an attractive force and a repulsive force generated between the stator and each magnetic pole plate of the rotor.

Also, contrary to the above embodiment, it is needless to say that the same effect can be obtained by changing the magnetism of the pole plate of the stator and fixing the polarity of the pole plate of the rotor.

In the above embodiment, the same operation and effect can be obtained by using a magnetic material without using a magnetic field generating means on the fixed side of the polarity of one of the magnetic pole plates on either the stator side or the rotor side. Needless to say.

It is needless to say that the same effect can be obtained by controlling and changing the polarity of both the stator and the rotor. Needless to say, the rotation direction is not limited to the clockwise direction and can be controlled to rotate counterclockwise.

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

As described above, in this embodiment, electric wiring and electrodes are not required from above the substrate, the element area can be reduced to 1/10 of the conventional one, and power consumption which does not contribute to driving can be reduced. This makes it possible to save energy by reducing the driving voltage to 1/10 of the conventional driving voltage.

Next, a micro-spring which is a second embodiment of the micro-actuator according to the present invention will be described with reference to FIGS.

The micro spring 4 in this embodiment
Reference numeral 0 denotes a magnetic pole table 41 and a laser beam irradiation means 20 having circularly polarized light. Here, the laser light irradiation means 20 is equivalent to the laser light irradiation means 20 described in the first embodiment.

The magnetic pole table 41 includes a fixed table 42 and a mover 43. The fixing base 42 has a concave cross-sectional shape, and is made of a transparent glass 42 (a) that is a material having a small thermal expansion coefficient that allows a laser beam to pass therethrough with low loss. 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 table 42 to form a pole plate.

Next, the mover 43 has a thin cylindrical shape.
A glass substrate 43 (a) made of transparent glass, which is a material having a small coefficient of thermal expansion that allows laser light to pass therethrough with low loss;
The glass spring 45 movably supports the fixing table 42 in a direction perpendicular to the plane.

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

In the above description, the fixed table 42 and the laser beam irradiating means 20, and the mover 43 and the laser beam irradiating means 20 respectively form a magnetic field generating means.

Next, when the magnetic pole plate is irradiated with a laser beam having circularly polarized light, a magnetic field is generated in the same manner as in the first embodiment.

Next, the operation of this embodiment will be described with reference to FIG. FIG. 8A shows a laser beam 2 having clockwise circularly polarized light from the glass substrate 43 (a) side on the mover 43.
8R, and a case where the fixing table 42 is irradiated with the laser light 28R having circularly polarized light clockwise from the glass substrate 42 (a) side. At this time, the copper thin film 43 of the mover 43
The (b) side has an N pole, and the copper thin film 42 (b) side of the fixing base 42 has an N pole.
It becomes a pole, and a repulsive force is generated between the fixed base 42 and the mover 43. Due to this repulsive force, the mover 43 moves upward in the figure.

Referring to FIG. 8B, FIG.
In (a), when the laser beam 28L having circularly polarized light counterclockwise from the glass substrate 42 (a) side of the fixed base 42 is irradiated, the copper thin film 42b side of the fixed base 42 becomes an S pole and the fixed base 42 and the movable element 43 Attraction occurs between them.

By controlling the polarities of the fixed base and the mover with the laser beam having circular polarization in this way, the mover can vibrate up and down.

It is needless to say that a similar effect 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 first aspect of the present invention, a magnetic pole plate formed by forming a thin film made of a conductive non-magnetic material on a substrate through which a laser beam passes is provided. By irradiating a laser beam having a circular or counterclockwise circularly polarized laser beam and irradiating the magnetic pole plate with a laser beam emitted from the laser beam irradiating unit, the laser beam is emitted according to the circular propagation of the circularly polarized laser beam. A first magnetic field generating means for generating a magnetic field by a rotating current consisting of an actual current generated on the thin film; and a predetermined magnetic field corresponding to a magnetic field generated by the first magnetic field generating means, the first magnetic field generating means being opposed to the first magnetic field generating means. A second magnetic field generating means for generating a 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. Between means And a magnetic field control means for generating a predetermined relative drive force.

Therefore, by using the repulsive force and attractive force of the magnetic force generated between the magnetic pole plates as the driving source, electric wiring and electrodes for power supply on the substrate become unnecessary. This makes it possible to increase the driving efficiency and increase the effective area ratio, thereby realizing miniaturization, energy saving and high performance of the microactuator. In addition, since the energy can be supplied spatially, a microactuator having a high degree of freedom in designing a power supply and an actuator independently of each other can be manufactured.

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

Therefore, by using the repulsive force and attractive force of the magnetic force generated between the magnetic pole plates as a drive source, electric wiring and electrodes for power supply on the substrate become unnecessary. This makes it possible to increase the driving efficiency and increase the effective area ratio, thereby realizing miniaturization, energy saving and high performance of the microactuator. In addition, since the energy can be supplied spatially, a microactuator having a high degree of freedom in designing a power supply and an actuator independently of each other can be manufactured.

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

Therefore, by using the repulsive force and attractive force of the magnetic force generated between the magnetic pole plates as a driving source, electric wiring and electrodes for power supply on the substrate become unnecessary. This makes it possible to increase the driving efficiency and increase the effective area ratio, thereby realizing miniaturization, energy saving and high performance of the microactuator. Also,
Since the energy can be supplied spatially, it is possible to manufacture a microactuator having a high degree of design freedom in which the power supply and the actuator are independent.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a micromotor according to a first embodiment of the present invention.

FIG. 2A is an end view taken along line XX in FIG. (B) is a whole perspective view of a rotor.

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

FIG. 4 is a schematic diagram when a magnetic plate is irradiated with laser light having circular polarization.

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

FIG. 6 is an overall perspective view of a micro spring according to a second embodiment of the present invention.

FIG. 7 is a sectional view of a spring according to a second embodiment of the present invention.

FIG. 8 is a schematic view showing a case where a microspring is irradiated with a laser beam having circularly polarized light in a second embodiment according to the present invention.

FIG. 9 is an overall perspective view of a micromotor according to the related art.

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

FIG. 11 is a schematic diagram showing a rotation principle of a micromotor in a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Micro motor 40 Micro spring 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 6a, 6b, 6c, 6d, 6e, 6f, 7a, 7b, 7
c, 7d, 7e, 7f Magnetic pole plate 28 Laser light having circularly polarized light 28R Laser light having circularly polarized light clockwise 28L Laser light having circularly polarized light counterclockwise 42 Fixed table 43 Mover 45 Glass spring Same as in the figure. The reference numerals indicate the same contents or corresponding parts.

Claims (3)

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