English Abstract

Actuator, Sensor, and Generator Using Dielectric Elastomer

Seiki CHIBA *1
Mikio WAKI *2
*1:Chiba Science Institute, Tokyo, Japan
*2:Wits Inc., Tochigi, Japan
Nippon Gomu Kyokaishi,(2017),90(2),36-40 General Review in Japanese

Dielectric Elastomer (DE) has a very simple structure comprised of polymer films (elastomers) sandwiched by two electrodes made of a flexible and elastic material, and can operate as an electric control actuator.
The operating principle is to use the horizontal deformation of elastomers that is a consequence of the synergistic combination of an electrostatic force and a repulsive force between the electrodes generated when a voltage difference is applied between the two electrodes.
Using a DE actuator makes it possible to achieve a highly efficient transduction from electric energy into mechanical energy (the theoretical transduction efficiency is 80-90%), which translates into a considerable energy saving compared to other actuator technologies such as electric motors with gearboxes. At the material level, this material has fast speed of response (over 100,000 Hz has been demonstrated for small strains), with a high strain rate (up to 600%), high pressure (up to 8 MPa), and power density of 1 W/g (for comparison, human muscle is 0.2 W/g and an electric motor with gearbox is 0.05 W/g).
The generator mode in DE uses the actuator mode process in reverse, transforming mechanical energy originating from the physical deformation of the elastomer film into electrical energy.

Keywords: Dielectric Elastomer, Soft Actuator, Generator, Sensor, Large Strain Rate, High Pressure, Fast Response, Flexible Electrodes