Architected elastomer networks for optimal electromechanical response

Abstract

Dielectric elastomers (DEs) that couple deformation and electrostatics have the potential for use in soft sensors and actuators with applications ranging from robotic, biomedical, energy, aerospace and automotive technologies. However, currently available DEs are limited by weak electromechanical coupling and require large electric fields for significant actuation. In this work, a statistical mechanics-based model of DE chains is applied to elucidate the role of a polymer network architecture in the performance of the bulk material. Given a polymer network composed of chains that are cross-linked, the paper examines the role of cross-link density, orientational density of chains, and other network parameters in determining the material properties of interest including elastic modulus, electrical susceptibility, and the electromechanical coupling. From this analysis, a practical strategy is presented to increase the deformation and usable work derived from (anisotropic) dielectric elastomer actuators by as much as 75−100%.