Controllable wrinkling in a prestretched dielectric elastomer sheet with striped electrodes.

Abstract

Controllable wrinkling of dielectric elastomer (DE) sheets is often applied to achieve some special applications such as diffraction gratings, optical sensors, soft actuators, and adjustable wetting surfaces. It is required to precisely predict and control the threshold voltage and wavelength of wrinkling. In view of the weakness of loss of tension criterion, a nonlinear plate theory considering the bending energy of DE sheet is utilized to investigate the wrinkling phenomenon in a prestretched DE sheet with striped electrodes. The results show that the threshold voltage of wrinkling is bigger than the corresponding voltage obtained from loss of tension, which results from the fact that the bending energy has a certain inhibiting effect on wrinkling of the DE sheet. Furthermore, the threshold voltage and wavelength of wrinkling can be effectively regulated by controlling prestretch. The striped electrodes can also effectively control the threshold voltage and wavelength. Especially, there exists an optimal width ratio of electrode corresponding to the lowest threshold voltage. The proposed method can be used to predict and control the behavior of wrinkling in the engineering applications of DE structures.