Modeling of bi-equilibrium states in dielectric elastomer

•We identify a new transition behavior in deformation of dielectric elastomer from one equilibrium state to another.•This transition is modeled and explained physically, under the developed equations of state.•We also investigate how the electromechanical loads affect the transition, for predictable and attainable stable state.

Dielectric elastomer is a soft active material, producing fast deformation under voltage-activation. Under a specific boundary condition, trussed dielectric elastomer elongates mimicking the behavior of biological muscle. During this process, dielectric elastomer experiences a snap from one deformation mode to another, though both at the electromechanical equilibrium states. Based on thermodynamics, models are established to investigate electromechanical coupling at the two equilibrium states. Particular emphasis is devoted to establishing the governing equations of the two deformation modes with physical interpretations. The transition of equilibrium state is discussed, to predict the attainable stable state for application.