Dynamic Response of Inflated Dielectric Elastomer Actuators Considering Material Viscoelasticity

Dielectric Elastomers (DEs) belong to a class of electrostatically driven ElectroActive Polymers (EAPs) employed effectively in electromechanical transduction technology. Inflated Dielectric Elastomer Actuators (DEAs) represent a special class of electromechanical transducers that exploit electro-elastic instability phenomena to generate out-of-plane axial symmetric deformations of circular membranes made up of non-conductive rubbery materials. Practically, DE membrane-based Inflated DEAs execute the transient motion which is significantly affected by the viscoelastic behavior of the DE membrane. In this paper, we present a nonlinear theoretical electromechanical framework to interrogate the effect of membrane viscoelasticity and strain stiffening effect on the dynamic behavior of the Inflated DEAs. The developed dynamic model investigates the DC and AC response, effects of membrane viscoelasticity on the stability transition, and natural frequencies of the Inflated DEAs. Further, a qualitative corroboration with experimental observations is articulated, highlighting the practical feasibility of the developed model. The results revealed in this study can find its potential use in the efficient design and development of inflated DEAs subjected to a time-dependent motion.