JP3026043B2 - Polyurethane elastomer 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 polyurethane elastomer actuator utilizing the electric field orientation of a dielectric material of a polyurethane elastomer material.

[0002]

2. Description of the Related Art The following materials are conventionally known as piezoelectric materials. It is a piezoelectric ceramic typified by lead zirconate titanate (PZT), a piezoelectric polymer typified by polyvinylidene fluoride (PVDF), or a composite of these. These are actually used as speaker and headphone materials and have shown excellent performance for certain applications.

[0003] However, the above-mentioned piezoelectric material is usually about 10k.
Since a voltage as high as V is required and the amount of electrostriction to be driven is not so large, it is not suitable for use as an actuator. On the other hand, recently, an actuator material using a specific charged gel has been developed. However, this type of material involves a chemical reaction, and thus has a problem that electrolysis and heat generation occur.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an actuator which does not require a very high voltage and hardly causes electrolysis or heat generation.

[0005]

In order to solve the above-mentioned problems, a polyurethane elastomer actuator according to the present invention is a polyurethane elastomer having a dielectric polyol , wherein a direct current electric field is applied to the polyurethane elastomer. Thus, the polyol is oriented in an electric field direction.

[0006]

When a DC electric field is applied to the polyurethane elastomer actuator of the present invention, the dielectric polyol of the polyurethane elastomer or the polyol having a substituent having a relatively strong dipole moment is oriented in the direction of the electric field. Then, a change in the conformation of the polymer constituting the polyurethane elastomer is induced.

In the present invention, it is necessary to apply a DC electric field in order to orient the polyol in the direction of the electric field, and the voltage required for this purpose is as high as that required by conventional piezoelectric materials (such as piezoelectric ceramics). do not need. Further, when the polyol is oriented in the direction of the electric field, no chemical reaction is involved, and therefore, almost no electrolysis or heat generation is involved. According to the configuration of the present invention, an anisotropic force is generated at an extremely high speed, and a significant work can be performed using the generated anisotropic force, which can be used for actuation. The mechanism by which the deformation or actuation occurs in the present invention is based on the orientation of the dielectric polyol by the electric field and the change in the conformation of the polymer induced thereby.

Accordingly, a higher-order structure such as anisotropy of the aggregate state of the polymer chains constituting the polyurethane elastomer is one of the factors that determine the magnitude of actuation.
The structural change occurs continuously and linearly by the electric field, so that the generated force and deformation can be linearly controlled by the electric field. This means that the action is constant without depending on the current even when measured under the condition that the current flows through the system.

[0009] Under the condition that current does not actually flow (for example, 1 m
The fact that the actuation can be performed at about A) suggests that energy can be prevented from being thermally dissipated, and that electrical energy can be converted into mechanical energy with high efficiency. That is, the shape of the polyurethane elastomer can be changed only by molecular orientation in a state where the effective current is substantially zero, and the mechanical deformation energy generated at the time of this shape change is used for actuation.

On the other hand, the fact that the driving performance can be brought out only by controlling the polymer structure in a state where the solvent is not contained at all in the case of the gel-like material is required for polyurethane-based materials.
This is a very great advantage considering that elastomer materials are versatile materials.

[0011]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following embodiments. As described in the column of action, the mechanism of the polyurethane elastomer actuator of the present invention is caused by a conformational change of a polymer chain, and has a higher responsiveness compared to a conventional charged gel that involves a chemical reaction. Is extremely fast. The response speed depends on the inducibility of the polyurethane elastomer, but is generally on the order of milliseconds to 10 milliseconds. The amount of change most greatly depends on the structure and physical properties resulting from the degree of crosslinking inherent to the polyurethane elastomer.

In order to utilize the elastic function of the polyurethane elastomer for the actuator, the chemical structure was further searched. Structural necessary components of the polyurethane elastomer are three components, that is, a component constituting a soft segment and a hard segment, and a curing agent necessary for modifying physical strength. Therefore, the driving performance of various related compounds and their combinations by an electric field was examined.

The polyurethane elastomer can be obtained by the following method. That is, the reaction is carried out by a conventionally known method using a polymer polyol, an organic polyisocyanate and a chain extender. For example, a method of reacting this polymer polyol with an organic polyisocyanate to obtain a urethane prepolymer and then reacting it with a chain extender, or a so-called one-shot method of simultaneously reacting the three components at a predetermined ratio. And so on. The NCO / OH molar ratio between the polymer polyol and the organic polyisocyanate is preferably in the range of 1.5 to 9.

As the polyisocyanate, 2
As long as it has at least two isocyanate groups,
For example, trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4
-Trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, 4,
4'-methylenebis (cyclohexylisocyanate), 1-methyl-2,4-cyclohexanediisocyanate, 1-methyl-2,6-cyclohexanediisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1,4-bis (isocyanatomethyl ) Cyclohexane, m-phenylene diisocyanate, p-
Phenylene diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, dianidin diisocyanate, 4, 4'-
Diphenyl ether diisocyanate, 1,3-xylylene diisocyanate, ω, ω'-diisocyanate-
Examples thereof include 1,4-diethylbenzene, polymethylene polyfernyl polyisocyanate, and modified isocyanurates, carbodiimides, and burets of these polyisocyanates. These are 1
Only one species may be used, or two or more species may be used in combination.

As the polyol, one or two of polyester-based polyol, polyether-based polyol, polycarbonate-based polyol and polybutadiene-based polyol are used.
It is possible to use a mixture of at least two or more kinds, or a mixture of the polyol and a polyolefin-based polyol as appropriate. As the polyester-based polyol, for example, a condensate of a polycarboxylic acid and a low-molecular-weight polyol,
There are those having a molecular weight of 500 to 10,000. In particular,
Poly (ethylene adipate) ("PEA"), poly (diethylene adipate) ("PDA"), poly (propylene adipate) ("PPA"), poly (tetramethylene adipate) ("PBA"), poly (hexamethylene adipate) ) (“PHA”), poly (neopenthylene adipate) (“PNA”), polyol consisting of 3-methyl-1,5-pentanediol and adipic acid, random copolymer of PEA and PDA, and PEA and PPA Random copolymer, PEA and PBA random copolymer, PHA
And a PNA random copolymer, or a caprolactone polyol obtained by ring-opening polymerization of ε-caprolactone, a polyol obtained by ring-opening β-methyl-δ-valerolactone with ethylene glycol, etc. It is preferable that the molecular weight is 500 to 10,000)
And each can be used alone or in combination. Furthermore, examples of the polyester polyol include a copolymer of at least one of the following acids and at least one of glycols.

Acids: terephthalic acid, isophthalic acid, phthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecane diacid, dimer acid (mixture), paraoxybenzoic acid, trimellitic anhydride, ε-caprolactone, β-methyl-δ valerolactone. Glycol: ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, polyethylene glycol, polytetramethylene glycol, 1,4-cyclohexanedimethanol, penta Erythritol, 3-methyl-1,5-pentanediol.

As the polyether polyol, for example, an alkylene oxide (eg, ethylene oxide, propylene oxide) obtained by ring-opening addition polymerization using a polyhydric alcohol (eg, diethylene glycol) which is an active hydrogen compound as an initiator, specifically, Examples include polypropylene glycol ("PPG"), polyethylene glycol ("PEG"), and a copolymer of propylene oxide and ethylene oxide. In addition, there is one having a molecular weight of 500 to 5,000, which is provided by cationic polymerization of tetrahydrofuran. Specifically, it is polytetramethylene ether glycol ("PTMG"), and tetrahydrofuran is a copolymer with another alkylene oxide, specifically, a copolymer of tetrahydrofuran and propylene oxide, and tetrahydrofuran. Copolymers with ethylene oxide and the like (all of which preferably have a molecular weight of 500 to 10,000) can be mentioned, and they can be used alone or in combination.

The polycarbonate-based polyol is obtained by condensation of a conventionally known polyol (polyhydric alcohol) with phosgene, chloroformate, dialkyl carbonate or diallyl carbonate, and is known to have various molecular weights. Particularly preferred as such a polycarbonate-based polyol is one using 1,6-hexanediol, 1,4-butanediol, 1,3-butanediol, neopentyl glycol, or 1,5-pentanediol as the polyol. Having a molecular weight of about 500 to 10,000. Each of them can be used alone or in combination.

The following can be used as the polybutadiene-based polyol. The hydroxyl group-containing liquid diene polymer has a molecular weight of 600 to 3000, an average number of functional groups of 1.7 to 3.0, and has 4 to 12 carbon atoms, a diene polymer, a diene copolymer, and a diene monomer and carbon number. Copolymers with 2 to 2.2 α-olefinic addition polymerizable monomers. Specific examples thereof include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, and butadiene-n-octadecyl acrylate copolymer. These liquid diene-based polymers can be produced, for example, by reacting a conjugated diene monomer by heating in a liquid reaction medium in the presence of hydrogen peroxide.

Further, the polyol component may be blended with a polyolefin-based polyol in which the double bond of the liquid diene-based polymer is saturated. As a curing agent,
It may be one commonly used in curing a urethane prepolymer to form a polyurethane elastomer. For example, a polyol compound, a polyamine compound and the like can be mentioned. Any of a primary polyol, a secondary polyol, and a tertiary polyol may be used as the polyol compound. Specifically, trimethylolpropane (“TM
P "), ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pecatanediol, 1,6-hexanediol, propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3-pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3- Hexanediol, cyclohexanediol, 2-ethyl-2- (hydroxymethyl) -1,3-propanediol and the like can be mentioned. As the polyamine compound, any of primary amine, secondary amine, and tertiary amine such as diamine, triamine, and tetraamine can be used. Specifically, aliphatic amines such as hexamethylenediamine, 3,3′-dimethyl-4,
An alicyclic amine such as 4'-diaminodicyclohexylmethane, 4,4'-methylenebis-2-chloroaniline,
Aromatic amines such as 2,2'3,3'-tetrachloro-4,4'-diaminophenylmethane and 4,4'-diaminodiphenyl; and 2,4,6-tris (dimethylaminomethyl) phenol; Can be These curing agents may be used alone or in combination of two or more.

As a method for mixing the above-mentioned curing agent with the urethane prepolymer obtained from the above composition and curing the urethane prepolymer, the mixing ratio of the curing agent to the urethane prepolymer, curing temperature, curing time, etc. And can be performed by a known method. The polyurethane elastomer used in the present invention may contain additives and the like. Additives include, for example, nonionic plasticizers, flame retardants, fillers, stabilizers, colorants, and the like.

Examples of the plasticizer include dioctyl phthalate (“DOP”), dibutyl phthalate (“DBP”),
Dioctyl adipate ("DOA"), triethylene glycol dibenzoate, tricresyl phosphate,
Dioctyl phthalate, fatty acid ester of pentaeristol, dioctyl sebacate, diisooctyl azelate, dibutoxyethoxyethyl adipate and the like can be used.

After molding a large number of polyurethane elastomers having the above-mentioned composition combinations into a plate having a thickness of 2 mm, a DC electric field was applied thereto and the mechanical response was measured using a strain sensor. That is, the upper and lower surfaces of the polyurethane elastomer molded into a plate shape were sandwiched between electrode plates, and a voltage was applied. The change in thickness of the polyurethane / elastomer was observed with a strain sensor, and the effects of potential and current were measured.

Hereinafter, specific examples will be described. Each example was performed according to the following procedure. A polyisocyanate component (hereinafter referred to as (2)) is added to 100 parts by weight of a polyol component (hereinafter referred to as (1)) and reacted at 85 ° C. for 1 hour under a nitrogen stream to obtain a urethane prepolymer having a terminal isocyanate group. . Isocyanate group (“NCO”) content of the obtained urethane prepolymer, and 80 ° C.
Was measured (shown in Tables 1 and 2). The viscosity of the urethane prepolymer was determined using a Haake rotational viscometer, Rotovisco RV-12.

100 parts by weight of the urethane prepolymer obtained as described above is kept at 80 ° C., and a curing agent (hereinafter referred to as (3)
Was melted and mixed, poured into a 2 mm-thick mold kept at 110 ° C. in advance, and left in an oven at 110 ° C. for 16 hours to complete the curing reaction. Then, the hardness (JIS-A) was measured (shown in Tables 1 and 2).
Here, the melting temperature when using 4,4′-methylenebis (dichloroaniline) as the curing agent was 140 ° C., and the melting temperature when using other curing agents was 80 ° C. Example 1 (1) Average molecular weight (refers to number average molecular weight; the same applies hereinafter)
1.979 of polyethylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd., trade name: PEG-2000) and polypropylene glycol having an average molecular weight of 2.007 (manufactured by Sanyo Chemical Industry Co., Ltd., trade name: Sanix PP2000) 7:
Blend with 3. (2) Paraphenylene diisocyanate (manufactured by DuPont, the same applies hereinafter): 16.1 parts by weight. (3) 4,4'-methylenebis (dichloroaniline)
(TCDAM, manufactured by Ihara Chemical Industry Co., Ltd.
The same applies hereinafter): 12.7 parts by weight. Example 2 (1) Poly-β-methyl- having an average molecular weight of 1.042
δ-Valerolactone polyol (Kuraray Co., Ltd., trade name Klapol L1010). (2) Paraphenylene diisocyanate: 30.7 parts by weight. (3) 1,4-butanediol (manufactured by Kanto Chemical Co., Ltd .; the same applies hereinafter): 5.8 parts by weight. Example 3 (1) Poly-3-methyl- having an average molecular weight of 1.510
1,5-pentane adipate polyol (Kuraray Co., Ltd., trade name Kurapol P1510). (2) Paraphenylene diisocyanate: 21.2 parts by weight. (3) 1.5 parts by weight of 1,4-butanediol and 2.9 parts by weight of trimethylolpropane (manufactured by Kanto Chemical Co., Ltd .; the same applies hereinafter). Example 4 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-pentane adipate polyol (manufactured by Kuraray Co., Ltd., trade name: Kurapol P3010, the same applies hereinafter). (2) Paraphenylene diisocyanate: 10.9 parts by weight. (3) 1,2-propanediol (manufactured by Kanto Chemical Co., Ltd .; the same applies hereinafter): 1.0 part by weight and trimethylolpropane: 1.4 parts by weight. Example 5 (1) Polypropylene glycol having an average molecular weight of 10.389 and capped with ethylene oxide (manufactured by Asahi Glass Co., Ltd., trade name X8202D, and so on). (2) Paraphenylene diisocyanate: 3.1 parts by weight. (3) 1,4-butanediol: 0.2 parts by weight and trimethylolpropane: 0.5 parts by weight. Example 6 (1) Polypropylene glycol having an average molecular weight of 10.389 and capped with ethylene oxide. (2) 4,4'-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Millionate MT, the same applies hereinafter): 4.8 parts by weight. (3) 1,4-butanediol: 0.2 parts by weight and trimethylolpropane: 0.4 parts by weight. Example 7 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-pentane adipate polyol. (2) Paraphenylene diisocyanate: 10.9 parts by weight. (3) Trimethylolpropane: 2.8 parts by weight. Example 8 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-pentane adipate polyol. (2) 4,4'-diphenylmethane diisocyanate: 17.0 parts by weight. (3) Trimethylolpropane: 2.8 parts by weight. Example 9 (1) Poly-3-methyl- having an average molecular weight of 2.945
1,5-pentane adipate polyol (Kuraray Co., Ltd., trade name Kurapol P3010). (2) 4,4'-diphenylmethane diisocyanate: 17.0 parts by weight. (3) Polyethylene adipate polyol having an average molecular weight of 993 (Nipporan 4002, manufactured by Nippon Polyurethane Industry Co., Ltd.): 29.2 parts by weight. Example 10 (1) Poly-3-methyl- having an average molecular weight of 1.948
1,5-pentane adipate polyol (manufactured by Kuraray Co., Ltd., trade name: Klapol P2010, the same applies hereinafter). (2) Paraphenylene diisocyanate: 16.4 parts by weight. (3) 1,2-propanediol: 3.2 parts by weight. Example 11 (1) Poly-3-methyl- having an average molecular weight of 1.948
1,5-pentane adipate polyol. (2) Paraphenylene diisocyanate: 16.4 parts by weight. (3) 4,4'-methylenebis (dichloroaniline)
... 10.3 parts by weight and triisopropanolamine (manufactured by Kanto Chemical Co., Ltd.) ... 1.1 parts by weight. Example 12 (1) Polybutylene adipate polyol having an average molecular weight of 2.055 (Nipporan 4010, manufactured by Nippon Polyurethane Industry Co., Ltd.). (2) Paraphenylene diisocyanate: 15.6 parts by weight. (3) 1,4-butanediol: 0.8 parts by weight and trimethylolpropane: 3.0 parts by weight. Example 13 (1) Polybutylene adipate polyol having an average molecular weight of 2.477 (Nipporan 3027, manufactured by Nippon Polyurethane Industry Co., Ltd.). (2) Paraphenylene diisocyanate: 12.9 parts by weight. (3) 1,4-butanediol: 0.8 parts by weight and trimethylolpropane: 3.0 parts by weight. Example 14 (1) Polycaprolactone polyol having an average molecular weight of 1.996 (Placcel 220, manufactured by Daicel Chemical Industries, Ltd .; the same applies hereinafter). (2) Paraphenylene diisocyanate: 16.0 parts by weight. (3) 1,3-butanediol (manufactured by Kanto Chemical Co., Ltd .; the same applies hereinafter): 3.8 parts by weight. Example 15 (1) Polycaprolactone polyol having an average molecular weight of 1.996. (2) Paraphenylene diisocyanate: 16.0 parts by weight. (3) 1,3-butanediol: 2.8 parts by weight;
1,4-butanediol: 1.0 part by weight. Example 16 (1) A polyol composed of ethylene glycol having an average molecular weight of 1.993, butylene glycol and adipic acid (manufactured by Sanyo Chemical Industry Co., Ltd., trade name: Sun Ester 24)
620). (2) Paraphenylene diisocyanate: 16.1 parts by weight. (3) 1,4-butanediol: 2.5 parts by weight and trimethylolpropane: 1.4 parts by weight. Example 17 (1) Polytetramethylene ether glycol having an average molecular weight of 1.986 (PTG manufactured by Hodogaya Co., Ltd.)
2000SN). (2) Paraphenylene diisocyanate: 16.1 parts by weight. (3) Trimethylolpropane: 3.6 parts by weight. Example 18 (1) Polyethylene adipate polyol having an average molecular weight of 2.022 (Nipporan 4040, manufactured by Nippon Polyurethane Industry Co., Ltd.). (2) Tolylene diisocyanate: 17.2 parts by weight. (3) Trimethylolpropane: 3.6 parts by weight.

The dimensions, shape, and measurement conditions of the elastomer molded as described above are as follows. Elastomer dimensions: 25 mm long x 25 mm wide x 2 mm thick. Elastomer shape: Flat, plate-like, with rubber-like elasticity. Applied voltage: 100 V to 1000 V, changed current value: 1 mA to 10 mA. When the applied voltage was less than 100 V, no deformation of the elastomer could be observed. Voltage 100V
The amount of change of the elastomer in the direction of the electric field observed as described above monotonically increased with an increase in the voltage. The maximum change of the elastomer in the direction of the electric field is shown in Example 4.
23.2 under the conditions of a voltage of 500 V and a current of 1 mA
μm (1.16%). Heat generation was not observed under the condition of 3 mA or less throughout the examples. The temperature of the elastomer was measured with a thermocouple inserted into the elastomer.

Tables 1 and 2 show the measurement results of the polyurethane elastomer actuator in each of the examples.

[0028]

[Table 1]

[0029]

[Table 2]

Next, each measurement result is evaluated. (Evaluation 1) In Example 4, a rapid contraction of 1.16% was observed in the electric field direction when an electric field of 500 V was applied. This is more than 100 times as large as the driving amount of 0.1% or less of the piezoelectric material polyvinylidene fluoride film under the same conditions. The response speed is several times slower than that of the polyvinylidene fluoride film, but it is considered to be very high considering that the elastic body has a hardness of 65 in JIS-A value. Incidentally, when the response speed is compared with that of the PZT-immobilized epoxy resin used as the electrostrictive material at the same driving amount, the response speed is two to three times faster.

In this embodiment, a large driving amount can be obtained by applying the low electric field as described above, and therefore, under the condition that almost no current value is observed without dielectric breakdown. (Evaluation 2) In Examples 10, 14, and 16 as well, large driving by an electric field is also observed. These are the implementation
It is presumed that, as in Example 4 , all have a relatively strong dipole moment such as an ester in the soft segment.

As to the types of polyols, ester-based polyols showed the largest variation, followed by ether-based polyols. In addition, in order to investigate the influence of the magnitude of the dipole moment, an experiment using only an olefin system having a weak dipole moment was conducted, but there was almost no change. (Evaluation 3) Structural necessary components of the polyurethane elastomer are three components of a component constituting a hard segment and a soft segment and a curing agent necessary for modifying physical strength. To generate a larger drive,
It is considered that a curing agent that easily inhibits generation of a segment is preferable. In one embodiment, it is desirable to use a curing agent having a side chain. This is because the presence of a side chain makes it difficult to form a hydrogen bond and thus hardly generates a hard segment, so that regulation by the hard segment on a structural change when a DC electric field is applied can be eased.

The polyurethane elastomer actuators of these embodiments are not driven by crystal grain boundaries like piezoelectric ceramics but are essentially different in principle, and are composed of soft actuators constituting an amorphous region of polyurethane elastomer. This is due to the electric field orientation of the segment dipole.
Therefore, it can be driven at a low voltage. In other words, the driving principle of this is a conventionally known orientation crystallized PV.
It is considered to be based on a novel driving principle completely different from the phenomenon of distortion due to the electric field of the DF and the grain boundaries.

Further, since the behavior of each soft segment causes distortion of the entire polyurethane elastomer actuator, a large force can be generated. Furthermore, since the polyurethane elastomer can be driven at a low voltage, that is, at a low energy, and the polyurethane elastomer is elastic and soft, it is possible to obtain an actuator having excellent workability. Also,
When a polyurethane elastomer is used, an actuator having an extremely large driving amount can be manufactured by changing the combination of the chemical compositions.

The polyurethane elastomer / actuator obtained as described above can be micromachined by microfabrication, so that it can be applied to manipulators used in microsurgeries that require high precision, soft and fine action. It is.

[0036]

As described above, according to the present invention, by applying a DC electric field, the dielectric polyol component is oriented in the direction of the electric field, and the structure of the elastomer is changed anisotropically. The shape of the elastomer can be changed only by molecular orientation in a state where the effective current is virtually zero (that is, while minimizing heat generation),
Further, the mechanical deformation energy generated at the time of this shape change can be effectively applied to actuation.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshiaki Kasazaki 172 Ikezawa-cho, Yamatokoriyama-shi, Nara Pref. Nita Plant (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 41/00- 41/26

Claims (1)

(57) [Claims] 1. A polyurethane elastomer having a dielectric polyol , wherein the polyol is oriented in the direction of an electric field by applying a DC electric field to the polyurethane elastomer. Elastomer actuator.