Modeling and Characterizing a Fiber-Reinforced Dielectric Elastomer Tension Actuator

Abstract

Creating dielectric elastomer actuators (DEAs) that mimic natural muscle has proven difficult, as a DEA provides in-plane expansion when actuated, while natural muscle creates contraction upon stimulation. Using a composite fiber-mesh dielectric, a DEA can create planar contraction when compressed through the thickness due to reorientation of the fiber reinforcement. This letter investigates the performance of a fiber-reinforced dielectric elastomer tension actuator (FRDETA) under a variety of loading conditions. We present modeling that considers the extensibility and packing density of the embedded fiber reinforcement to predict the mechanical response of the actuator. We then experimentally validate the results and determine the optimal fiber angle to maximize mechanical work for a FRDETA under a dead load. The FRDETAs tested were able to obtain tensile stresses of 880 kPa, tensile strains up to 14.7%, and a mass-specific energy density of 10.7 J/kg, which all fall within the ranges reported for natural muscle. Overall, these tensile actuators present an easily implementable solution for creating tension in larger soft robotic systems.