Patent ID: 7915792

Claim:
An elastomer actuator having a sheet body, comprising: an elastic dielectric elastomer layer; and electrodes provided on the sides of the dielectric elastomer layer without performing a preliminary straining process, the elastomer actuator being a cylindrical body formed by rolling the sheet body in a spiral manner, wherein the elastomer actuator is actuated by applying a voltage to the electrode and stopping the voltage application, so that the dielectric elastomer layer is expanded and contracted, wherein a material forming the elastic dielectric elastomer layer has: a low strain region, where the value of a strain based on a stress acting on the dielectric elastomer layer varies from zero to a value that is greater than and close to zero; and a high strain region, where the value of the strain is greater than that in the low strain region, wherein the Young's modulus in the low strain region is less than the Young's modulus in the high strain region, and wherein a coil spring is located in the cylindrical sheet body.