LAUSR

Abstract Reducing the operating voltage of dielectric elastomer actuator (DEA) without compromising breakdown strength (Eb) and elasticity has been one of the grand challenges to its practical application in various fields, such as the wearble devices. In this study, novel dielectric elastomers offering intrinsically good integrated performances are achieved by introducing CNT-Al2O3 core-shell nanostructures to form various nanocomposites. Dielectric constants (er) of these nanocomposites show a rapidly increasing with the increase of loading amount of CNT-Al2O3 fillers, while the elastic modulus (Y) and the breakdown strength (Eb) vary slightly. By incorporating 0.9 wt.% CNT-Al2O3 fillers, the dielectric constant and actuation coefficient of the nanocomposite increase more than by 200% compared with the pristine DEA, and the breakdown strength remains above 65 V/μm. Correspondingly, the actuation strain of the 0.9 wt.% composite is 200% higher than that of pristine DEA under the same driving voltage. For the same actuation strain or deflection, the required driving voltage of the actuator made of CNT-Al2O3 nanostructure-based composite is only 50% of that of pristine DEA. Consequently, the achieved balance among a high er, high Eb, and stable Y in our system can assure a high actuation strain under a low driving field, stable stiffness, and improved safety for DEA. In addition, since the tunable electromechanical sensitivity encompasses a wide range, the as-prepared nanocomposites offer an alternative candidate to fabricate the smart devices integrated with various strain components by modulating the composition of the materials.