JPH0814153A - Driving of plzt and its microactuator - Google Patents

Abstract

PURPOSE:To provide a driving method of a PLZT excellent in distortion quantity and a microactuator showing sufficient operation quantity by way of using it. CONSTITUTION:It is a driving method of a PLZT to deform a light distortion body consisting of Pb1-0.03La0.03(Zr0.52Ti0.48)1-0.03/4O3 by irradiation of a laser beam wavelength of which is 350-380nm and it is constituted to irradiate the laser beam wavelength of which is 350-380nm on the light distortion body through an optical fiber. Consequently, it is possible to deform the PLZA (3/52/48) in large distortion quantity by irradiation of a specified laser beam, to provide large operating quantity even in the case when a light receiving area is small by irradiation of the laser beam through the optical fiber and to form a microactuator which can be easily built in a micro device such as an endoscope, etc., and is practical.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving a PLZT suitable for forming a micromachine or the like and having an excellent amount of distortion, and a microactuator using the same.

[0002]

_{2. Description of the Related} Art Pb _1-0.03 La _0.03 (Zr _0.52 T
i _0.48 ) _{1-0.03 / 4} O ₃ optical strain material (PLZT (3
/ 52/48)) (JP-A-61-20).
No. 5620). Such PLZT (3/52/48)
Is highly efficient in converting light energy into mechanical energy, and is expected to be used for microactuators in pipe maintenance and medical micromachines.

Conventionally, the above-mentioned PLZT (3/52/4)
As the driving method 8), a method of irradiating ultraviolet rays through a mercury lamp or the like has been known (Japanese Patent Application Laid-Open No. 62-13992).
24, JP-A-4-164581). However, there is a problem that the amount of distortion is extremely small, on the order of 1/10 ^4, and there is a problem that the amount of operation is so small that it is difficult to be practically used as a microactuator.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of driving a PLZT (3/52/48) which is excellent in the amount of distortion, and to obtain a microactuator exhibiting a sufficient amount of operation using the method. .

[0005]

The present invention provides Pb _1-0.03 L
a method of driving a PLZT, characterized in that an optical strain body made of a _0.03 (Zr _0.52 Ti _0.48 ) _{1-0.03 / 4} O ₃ is deformed by irradiation with a laser beam having a wavelength of 350 to 380 nm, and the optical strain described above. The wavelength is 350 to 3 through the optical fiber to the body
An object of the present invention is to provide a microactuator characterized by irradiating 80 nm laser light.

[0006]

[Function] PLZT (3/52/48) with wavelength of 350 to 3
By irradiating with a laser beam of 80 nm, it can be deformed with a large amount of strain. The amount of strain is about 1/10 ^3, which is about 10 times that of ultraviolet rays, but the reason why such a high strain is provided is unknown.

Further, laser light can be efficiently transmitted through an optical fiber, and the optical fiber can be easily incorporated into a micro device such as an endoscope. And a microactuator with a large operation amount can be formed by the large distortion amount.
With ultraviolet rays, the amount of irradiation light is insufficient due to transmission loss due to an optical fiber, and it is difficult to form a microactuator with an operation amount that can be used practically.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The driving method according to the present invention uses Pb _1-0.03 La
_0.03 (Zr _0.52 Ti _0.48 ) _{1-0.03 / 4} O _3, that is, PLZ
An optical strainer made of T (3/52/48) was used for
It is deformed by irradiation with a laser beam of up to 380 nm.

The photostrictive body may be made of a single substance of PLZT (3/52/48), or may be formed as a photostrictive bimorph. Further, the form of the optical strain body can be appropriately determined according to the purpose of use.

The photostrictive bimorph is such that the direction of polarization is opposite to that of a photostrictive material that expands when irradiated with light and an electrostrictive material (substantially the same as the photostrictive material) that deforms when an electric field is applied. The optical strain bimorph used in the present invention is formed by using PLZT (3/52/48) as the optical strain material.

As the electrostrictive material, for example, quartz, Zn
S, La ₂ S ₃ , SbSI, SbSI · SbSBr, KH ₂ PO
₄ , KH ₂ PO ₄ · KD ₂ PO ₄ , glycine sulfate, Rb ₂ ZnB
r ₄ , α-LiIO ₃ (Cr added), LiNbO ₃ , LiNbO
₃ (Fe added), KNbO ₃ (Fe added), SbNbO ₄ , (S
r, Ba) Nb ₂ O ₆ , (Pb, La) Nb ₂ O ₆ , Ba ₂ NaNb ₅
O ₁₅ (Fe and Mo added), BaTiO ₃ , BaTiO ₃ (Fe added), BaTiO ₃ .CaTiO ₃ , PbTiO ₃ , PbTiO _3.
La (Zn _2/3 Nb _1/3 ) O ₃ , PbTiO ₃ .Pb (Mg _1/2 W
_1/2 ) O ₃ , PbZrO ₃ · PbTiO ₃ (Nb added), K (T
a, Nb) O ₃ , PLZT and the like. Particularly, as a preferred electrostrictive material, PLZT (3
/ 52/48), 0.91Pb (Mg _1/3 W _2/3 ) O ₃ −
0.09PbTiO ₃ , 0.73Pb (Zr, Ti) O ₃ −
_{0.27Ba (Zr, Ti) O 3} , 0.91Pb (Zn 1/3 Nb
_2/3), such as O ₃ -0.09PbTiO _3, and the like.

The light applied to the optical strainer has a wavelength of 350 to 3
80 nm laser light. The laser light is not particularly limited except for the wavelength, and can be obtained by, for example, XeF excimer laser (351 nm), Nd: YAG laser THG conversion (355 nm), or dye laser in the wavelength range. The preferred wavelength of the laser light from the viewpoint of the amount of distortion and the like is 355 to 375 nm, especially 360 to 3
70 nm.

The method of irradiating the photostrictive body with laser light is arbitrary, and an appropriate optical system can be formed by using a plurality of light sources, reflecting mirrors, etc., if necessary. A system in which laser light is applied to the entire surface of the optical strain body as much as possible is preferable. In the case where a microactuator is formed, a laser beam having a predetermined wavelength can be applied to the optical strainer via an optical fiber. In a system where remote control is desired, such as an endoscope, an irradiation system via an optical fiber is advantageous.

The driving method according to the present invention uses a PLZT (3/52).
/ 48) a relay mechanism that controls opening and closing of the contacts of an electric circuit by utilizing the expansion / contraction operation of a light distortion material composed of a single object or the bending operation of a light distortion bimorph, a micromanipulator, a microvalve, The present invention can be used for various purposes such as formation of a microactuator constituting a driving mechanism in a micro machine such as a micro gripper. Examples thereof are shown in FIGS.

FIG. 1 exemplifies the expansion and contraction operation of the optical strain bar 1 made of PLZT (3/52/48), and the arrows indicate laser light. In this case, when the laser beam is irradiated, the optical strain bar 1 is in an extended state as shown by a virtual line,
When the irradiation of the laser beam is stopped, the laser beam is reduced and returns to the original state.

Therefore, by utilizing the expansion / contraction operation of the optical strain rod 1 described above, for example, the opening / closing mechanism of the valve 11 and the flow rate adjusting mechanism as shown in FIG. The gripper mechanism 2 and the like can be formed. In FIG. 2, by irradiating a laser beam to the bulb 11 made of a photostrictive rod through an optical fiber 13 provided on a support plate 12 fixed to a pipe 14, the bulb is elongated to close the pipeline. It has become.

In FIG. 3, a laser beam is applied to a connecting rod 26 composed of an optically distorted rod connected between one ends of pinching rods 21 and 23 rotatably bound via a pin 25. The rod is extended, and the pinch bar 2
By the rotation of the first and second rotations, the engagement portions 22 and 24 at the other end are closed and gripped.

On the other hand, FIG. 4 exemplifies a gripper mechanism utilizing the bending operation of the optical strain bimorph. This shows a micro gripper for application to an endoscope, etc., and includes a pinch bar 3 made of a photostrictive bimorph, an optical fiber 6 for irradiating one side with a laser beam, and a And a non-optical strain type clamping rod 4 which is pressed against the clamping rod deformed by the irradiation of laser light through an optical fiber.

The gripping rod 3 made of a photostrictive bimorph is placed in opposition with a gap so that the hook-shaped tip 31 of the gripping rod 3 can be pressed into contact with the hook-shaped tip 41 of the non-light distortion type gripping rod 4. And the tail is fixed to the non-optical distortion type pincer. The tail portion of the non-optical strain pincer 4 is inserted and fixed between the sleeve 5 and the coating layer 61 of the optical fiber 6. The non-photostrictive sandwiching bar can be formed of an appropriate material that is not photostrictive, such as various metals, ceramics, and polymers.

The optical fiber 6 is mounted in the sleeve 5 so that a laser beam can be applied to the side of the optical distortion member 33 composed of PLZT (3/52/48) on the pin 3 composed of the optical distortion bimorph. . The optical fiber 6 in the illustrated example is formed by providing a coating layer 61 on the outer periphery of an optical fiber bundle 62, and the laser light source is disposed at the end of the optical fiber (not shown).

In the above, as shown in FIG. 5, a laser beam is irradiated (arrow) through the optical fiber 6 on the side of the optical strainer 33 of the sandwich bar 3 made of a photostrictive bimorph, so that the sandwich bar 3 is bent and deformed. Then, the distal end portion 31 is pressed against the distal end portion 41 of the sandwiching bar 4 opposed thereto to hold the grip target. Restoration of the pinch bar composed of the optically distorted bimorph (FIG. 4) can be achieved by stopping the irradiation of the laser beam, whereby the gripped object can be released.

The above micro gripper mechanism has a simple structure, can be easily miniaturized, does not require temperature control, is not affected by electromagnetic noise, has no problem of electric shock, and can be safely applied to blood vessels and the like. For example, by providing it at the tip of the optical fiber provided in the image guide, collecting necessary samples while observing the inside of blood vessels and pipes, and supplying chemicals and repair materials to predetermined locations. Can be used. When applied to a living body, necessary functions such as antithrombotic properties are imparted as necessary by a surface treatment method using an antithrombotic agent or the like.

As described above, in the photostrictive bimorph, when the photostrictive material is irradiated with laser light, the photostrictive material expands and generates a voltage, and the voltage is applied to the electrostrictive material via the electrodes at both ends, and the electrostrictive material shrinks. As a result, the photostrictive bimorph forms a curved state in which the diameter of the electrostrictive material side is reduced, and returns to the original state when the irradiation of the laser beam is stopped. Therefore, various mechanisms such as a grip mechanism and a switching mechanism can be formed by utilizing such an operation.

The driving method of the present invention and the microactuator using the same are applicable to thermostats and controllers in micromachines for pipe maintenance and medical use, controllers for automobiles, controllers for automatic opening / closing greenhouse windows and fire doors, and the like. It can be preferably used for various devices.

Example 1 PLZT (3/52/48) by hot press sintering
A sintered body (length 2 mm × width 4 mm × thickness 0.5 mm) made of, and a silver paste is baked on each opposing surface of the width × thickness to attach electrodes, and then 2 kV is applied between the electrodes. / Mm
By applying the voltage, the sintered body was polarized to form a photostrictive body. A wavelength of 351 is formed on the vertical x horizontal surface of this optical strainer.
5mJ / pulse with XeF laser light of nm, frequency 10H
Irradiation at z showed elongation of 2 μm in the vertical direction, and the amount of strain was 1/10 ³ .

Comparative Example A mercury-xenon lamp with a wavelength of 3
When irradiated with an ultraviolet ray of 65 nm at an intensity of 10 mW / cm ² , the longitudinal elongation (displacement amount) was 0.2 μm and the strain amount was 1/10 ⁴ .

[0027]

According to the present invention, PLZT (3/52/48) can be deformed with a large amount of distortion by using a predetermined laser beam as irradiation light, and the laser beam can be transmitted through an optical fiber. It is possible to obtain a large amount of movement even when the light receiving area is small by the irradiation of (1), and it is possible to form a practical microactuator that can be easily incorporated into a microdevice such as an endoscope.

[Brief description of drawings]

FIG. 1 is an operation explanatory view of an optical strainer.

FIG. 2 is an explanatory cross-sectional view of an example of a valve mechanism.

FIG. 3 is an explanatory view of a gripper mechanism.

FIG. 4 is an explanatory sectional view of another gripper mechanism (open state).

FIG. 5 is an explanatory cross-sectional view of the gripper mechanism (holding state).

[Explanation of symbols]

1: Photostrictive rod (11: bulb made of optical strained rod 26: connecting rod made of optical strained rod) 3: pinched rod made of optical strained bimorph 4, 21, 2
3: sandwiching bar 6, 13: optical fiber

Claims (3)

[Claims] 1. Pb _1-0.03 La _0.03 (Zr _0.52 T
i _0.48 ) A _{photostrictive} body made of _{1-0.03 / 4} O ₃ having a wavelength of 350
A method for driving a PLZT, wherein the deformation is performed by irradiation with a laser beam of up to 380 nm. 2. Pb _1-0.03 La _0.03 (Zr _0.52 T
i _0.48 ) A _{microactuator} characterized in that a laser beam having a wavelength of 350 to 380 nm is irradiated to an optical strainer made of _{1-0.03 / 4} O ₃ via an optical fiber. 3. The _{photostrictive} body is _composed of Pb _1-0.03 La _0.03 (Zr _0.52
The driving method or the microactuator according to claim 1, comprising a single substance of Ti _0.48 ) _{1-0.03 / 4} O ₃ or a photostrictive bimorph.