Semi-analytical modeling of electro-strictive behavior in dielectric elastomer tube actuators

Abstract

Dielectric elastomer tube actuators (DETAs) facilitate versatile soft robotic motions when activated by electric fields. However, optimizing their performance necessitates understanding complex deformation behaviors under different electrical loading patterns. While prior analytical models provide valuable insights, many rely on assumptions like infinite-length and uniform conditions, limiting their ability to capture experimentally-observed nonuniform deformations. This paper presents a semi-analytical approach permitting both radial and longitudinal electrostatic effects by modeling a dielectric tube of effectively infinite-length. It also incorporates the crucial compression-torsion behavior for soft actuator designs. We validate the model against finite element simulations, achieving excellent agreement. Our efficient technique successfully predicts intricate deformation phenomena in DETAs under combined electrical, mechanical, and geometric effects. Results show the model effectively captures axial and twisting deformations, overcoming limitations of linear twist angle assumptions. This analytical framework offers a powerful tool for optimizing next-generation soft actuators across diverse cutting-edge engineering and robotic applications.