Effect of temperature on the electromechanical actuation of viscoelastic dielectric elastomers

The electromechanical deformation of viscoelastic dielectric elastomers (DEs) is primarily governed by three material parameters: permittivity, Young's modulus, and relaxation time. All three parameters are functions of temperature, so a complete description of the electromechanical behaviour of a DE must take thermal effects into account. In this paper, we have established a physical model for viscoelastic DEs that takes temperature effects into consideration. The actuation of a DE was measured under different temperatures to verify the model. A peak actuation stretch was obtained at around 363 K both experimentally and theoretically. Moreover, we also demonstrate the contribution of strain-stiffening induced by greater pre-stretching to the improvement of thermostability.