Simplified discrete model for axisymmetric dielectric elastomer membranes with robotic applications

TL;DR

This paper introduces a simplified 1D discrete differential geometry model for axisymmetric dielectric membranes, enabling efficient simulation of their nonlinear electro-mechanical behavior for soft robotic applications.

Contribution

The paper presents a novel DDG-based numerical model that accurately captures the nonlinear dynamics of inflatable dielectric membranes, improving simulation efficiency and aiding soft robot design.

Findings

Model accurately predicts membrane behavior under pressure and electrical stimuli.

Snap-through phenomena enhance the functional range of soft robots.

Validated with hyperelastic benchmarks and applied to robotic prototypes.

Abstract

Soft robots utilizing inflatable dielectric membranes can realize intricate functionalities through the application of non-mechanical fields. However, given the current limitations in simulations, including low computational efficiency and difficulty in dealing with complex external interactions, the design and control of such soft robots often require trial and error. Thus, a novel one-dimensional (1D) discrete differential geometry (DDG)-based numerical model is developed for analyzing the highly nonlinear mechanics in axisymmetric inflatable dielectric membranes. The model captures the intricate dynamics of these membranes under both inflationary pressure and electrical stimulation. Comprehensive validations using hyperelastic benchmarks demonstrate the model's accuracy and reliability. Additionally, the focus on the electro-mechanical coupling elucidates critical insights into the membrane's behavior under varying internal pressures and electrical loads. The research further translates these findings into innovative soft robotic applications, including a spherical soft actuator, a soft circular fluid pump, and a soft toroidal gripper, where the snap-through of electroelastic membrane plays a crucial role. Our analyses reveal that the functional ranges of soft robots are amplified by the snap-through of an electroelastic membrane upon electrical stimuli. This study underscores the potential of DDG-based simulations to advance the understanding of the nonlinear mechanics of electroelastic membranes and guide the design of electroelastic actuators in soft robotics applications.