Evolutionary Electromechanical Stability in Stressed Viscoelastic Dielectrics

Constant mechanical load offers stabilization in the electromechanical actuation of dielectric elastomer. Due to the viscoelasticity, the electromechanical coupling performance of dielectric elastomer varies with time as its stability evolves. The parameters of viscoelasticity are calibrated experimentally. By establishing a thermodynamics model, the evolutionary paths of electromechanical deformation are classified and investigated, where a transition, from unstable to stable, is identified. The critical time and critical load on the transition is determined, providing a path forward for improving performance of dielectric elastomer.

Highly improved electro-actuation of dielectric elastomers by molecular grafting of azobenzenes to silicon rubber

Electromechanical deformation of silicone rubbers was efficiently improved by chemically grafting with strong polar azobenzenes.

Temperature Influence on the Viscoelastic Electromechanical Deformation of Dielectric Elastomer

Temperature can significantly affect the performance of a viscoelastic dielectric elastomer (DE). In the current study, we use a thermodynamic model to characterize the influence of temperature on the viscoelastic electromechanical response undergoing a constant electric load by taking into account the temperature dependent elastic modus and dielectric constant. Due to the significant viscoelasticity in the dielectric elastomer, DE membrane creeps in time and the inelastic stretch of DE is smaller than that of the total stretch. The results show that the total stretch of the viscoelastic electromechanical deformation increases with the increasing temperature until suffering electromechanical instability at a high temperature; the actuation performance is dominated by the moduli of the elastomer. This may be used to guide the design of dielectric elastomer actuators undergoing temperature variation.