Thermal and strain-stiffening effects on the electromechanical breakdown strength of dielectric elastomers

The electromechanical breakdown strength determines the limit of a dielectric elastomer for its use in actuators and energy harvesters. We investigated experimentally and theoretically the thermal and strain-stiffening effects on the electromechanical breakdown strength. The stain-stiffening induced by large stretch highly enhance the maximum energy density and breakdown strength. A temperature dependence of breakdown strength is consistent with the electromechanical breakdown model by taking into account of the strain-stiffness effect of dielectric elastomer. Furthermore, the stain-stiffening also increases the thermal sensitivity of breakdown strength.