An Electromechanical Model for the Estimation of Breakdown Voltage in Stretchable Dielectric Elastomer

Dielectric elastomer (DE) is capable of large deformation under electrical excitation. However, DE is susceptible to breakdown failure in this electromechanical actuation. Using an analogy of fracture mechanics, we establish an energetic model to estimate the breakdown voltage of DE in actuation. The non-linear characteristics, including material parameters, stretch ratios, and ambient temperature are involved to determine the critical condition of breakdown failure. The model is verified by experimental data of VHB membranes, and then extended to different DE materials. With respect to applications, two types of classic dielectric elastomer actuators (DEAs) are analyzed, and their breakdown voltages are evaluated. This study can provide a path for optimization of DE in electromechanical actuator and insulator applications.