JPH0524108B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of the Invention] The present invention comprises a novel material for a photostrictive actuator. [Background of the Invention] The importance of actuator systems is increasing with the development of mechatronic devices such as robots. Conventional actuators have generally been electromagnetic actuators that use electromagnetic force as a driving source, but in recent years piezoelectric actuators that utilize the piezoelectric effect of solids have been attracting attention. This piezoelectric actuator is a solid material that expands and contracts in shape when voltage is applied, and is an actuator that utilizes this shape change (or the mechanical energy required to prevent expansion and contraction). This piezoelectric actuator solves the problems of high power consumption and noise generation that were problems with conventional electromagnetic actuators. However, when using a piezoelectric actuator, equipment such as a power source and wiring for supplying electric power is still required. [Object of the Invention] The present invention aims to provide a novel photostrictive actuator material that exhibits a useful function as an actuator, that is, a conversion element material that can directly convert optical energy into mechanical energy with high efficiency. purpose. [Summary of the Invention] The present invention is based on the general formula: (Pb _1-x La _x ) (Zr _y Ti _z ) _1-x/4 O ₃ [However, 0.0001≦x≦0.09, 0.3≦y≦0.8,
and y+z=1] A photostrictive actuator material made of zirconium lead lanthanum titanate is provided. [Detailed description of the invention] It is already known that zirconium lead lanthanum titanate represented by the general formula (Pb, La) (Zr, Ti) O ₃ exhibits piezoelectric properties, and has been given the abbreviation PLZT. and is used as a piezoelectric material. In addition,
It is not caused by temperature changes caused by light irradiation.
Until now, there have been no reports of the essential photostriction phenomenon. As a result of intensive research into the properties of PLZT against light, the present inventor discovered that PLZT, in which each component has a ratio within a specific range, exhibits distortion behavior when irradiated with light, and further developed the photodistortion properties using a photostriction actuator. The present invention was achieved by devising a method for using the method as a method. In a photostrictive actuator, a high electric field is generated inside the solid-state element by light irradiation (this is called a photovoltaic effect), and distortion is induced by the piezoelectric effect caused by the electric field. Therefore, since no electric power is required to drive the photostrictive actuator, the auxiliary equipment can be easily simplified even when compared to a piezoelectric actuator. Furthermore, since the photostrictive actuator can be operated by irradiating light even from a remote location, it can be advantageously used especially when installing the actuator in a location where it is difficult to install wiring facilities. According to the research of the present inventor, not all zirconium lead lanthanum titanate exhibits photostrictive properties, but those with a specific component ratio, that is, those with the general formula (Pb _1-x La _x ) (Zr _y Ti _z ) _1-x/4 O ₃ [However, 0.0001≦x≦0.09, 0.3≦y≦0.8,
and y+z=1] Only zirconium lead lanthanum titanate shown as follows exhibits photostrictive properties that can be used practically. In particular, in the above general formula, 0.01≦x≦0.06 and
It is preferable that 0.4≦y≦0.7, and more preferably 0.02
Those satisfying ≦x≦0.04 and 0.05≦y≦0.60 exhibit particularly high photostriction characteristics. The zirconium lead lanthanum titanate exhibiting photostrictive properties provided by the present invention can be produced by appropriately adjusting the component ratio according to a known method for producing zirconium lead lanthanum titanate. That is, for example, PbO, La ₂ O ₃ , ZrO ₂ ,
and TiO ₂ according to the desired composition and sintering this using a known hot press sintering method or the like. When using the zirconium lead lanthanum titanate exhibiting the photostrictive properties of the present invention as a photostrictive actuator, for example, the sintered body is cut into chips of an appropriate size, electrodes are attached to the surface of the chips, and then polarization treatment is performed. etc. Although there is no particular limitation on the light that can be used when using the photostrictive actuator of the present invention, the maximum performance is found in the wavelength range from ultraviolet light to visible light. Further, both full-color light and monochromatic light can be used. However, in terms of energy efficiency and ease of operation, it is practically advantageous to use ultraviolet light made monochromatic using a filter or the like, or argon laser light. Note that the photostrictive actuator material of the present invention can also be used as a photoacoustic conversion element. Next, Examples and Comparative Examples of the present invention will be shown. [Examples 1 to 5 and Comparative Example 1] By adjusting the blending amounts of PbO, La ₂ O ₃ , ZrO ₂ and TiO ₂ , the general formula: (Pb _1-x La _x ) (Zr _y Ti _z ) ₁ Zirconium lead lanthanum titanate with varying xyz _{at -x/4} O
A sintered body was produced by sintering at 1220°C. This sintered body was cut into chips of 3 mm x 2.6 mm x 14 mm, and electrodes were attached to the surface using silver paste.
Next, the chip was polarized in the direction in which it was cut out by 3 mm, and then the cut surface of 3 mm x 14 mm was optically polished. The above optically polished surface was irradiated with light obtained by filtering high-pressure mercury lamp light to make it almost monochromatic (approximately 366 nm). This irradiation was carried out under the conditions that the externally applied electric field was zero, the electrodes were kept open, and light energy was applied to the optically polished surface in steps at a rate of about 17 mW/cm ² . The photo-induced strain of the sample chip caused by the above irradiation was measured using a strain gauge. The result is the first
Shown in the table.

【table】

[Table] That is, zirconium lead lanthanum titanate having the component ratio specified in the present invention exhibits remarkable photostrictive properties and is useful as a material for photostrictive actuators.

Claims (1)

[Claims] 1 General formula: (Pb _1-x La _x ) (Zr _y Ti _z ) _1-x/4 O ₃ [However, 0.0001≦x≦0.09, 0.3≦y≦0.8,
and y+z=1] A photostrictive actuator material made of zirconium lead lanthanum titanate. 2. The photostrictive actuator material according to claim 1, wherein in the general formula of zirconium lead lanthanum titanate, 0.01≦x≦0.06 and 0.4≦y≦0.7. 3. The photostrictive actuator material according to claim 2, wherein in the general formula of zirconium lead lanthanum titanate, 0.02≦x≦0.04 and 0.5≦y≦0.60.