Snap-through instability in rotating dielectric elastomer tubes

Abstract

Dielectric elastomers (DEs) have been widely used in soft robotics, high-performance actuators, and bioengineering. However, they may suffer from more failure modes than pure elastic elastomers when undergoing rotational motion. In this paper, we present a theoretical analysis of the finite deformation of rotating DE tubes, addressing the challenges associated with rotational motion in DEs. Our study focuses on the combined influence of a radial electric field and an axial pre-stretch. We numerically calculate three different materials, including neo-Hookean, Gent, and Ogden models, for rotating DE tubes and find that the snap-through instability caused by rotation occurs only in tubes with the Ogden model, resulting in dramatic deformation. Moreover, we study the effects of geometric dimensions and external loads and reveal the competition mechanism between the snap-through instability and electrical breakdown of DE tubes under external voltage. Significantly, our work presents practical thresholds that offer comprehensive guidance for designing and controlling of rotating DE tubes, preventing electrical breakdown during rapid deformation through the adjustment of external loads. This study provides novel insights and practical recommendations for the field of nonlinear deformation in rotating DE tubes.