An Integrated Design and Fabrication Strategy for Planar Soft Dielectric Elastomer Actuators

Abstract

Dielectric elastomers (DEs) are promising soft actuators for use in soft material robots, due to their considerable voltage-induced strain. The actuator's behavior is highly nonlinear due to the complex interplay between the DE, the support structure, and the input electric field, making it a big challenge to automatically design dielectric elastomer actuators (DEAs). Here, in this article, we present an integrated design strategy for planar DEAs, aiming to realize their full potential. To endow the actuator module with the maximal actuation strain, we carry out dimensionless analysis to identify the key design variables, develop a fast finite element analysis model, and thoroughly investigate how the geometric structuring and the material prestretch tailor the voltage-induced deformation. We also provide a fabrication strategy by patterning the compliant electrodes on the DE membrane and then directly printing the support structure made of thermoplastic polyurethane. The experiments show that the optimized actuator obtains a remarkable nominal strain up to 38.6%. We also characterize the dynamic performance of the optimized actuator, evaluate its energy density and power density, and develop a soft locomotion robot that can crawl through a confined tunnel, at a fast moving speed up to 0.17 body length/s.