Dynamic Mechanical and Electromechanical Behavior of Microporous Dielectric Elastomer in Soft Robotics Actuators

This study reports the behavior of a microporous polyacrylate dielectric elastomer under controlled mechanical and electrical loading to assess its suitability for soft actuators in robotics. The investigation focuses on the behavior of elastomers subjected to cyclic mechanical loading with prestrain conditions, evaluating stress-softening, energy dissipation, and residual strain over multiple cycles to understand the suppression of the Mullins effect. Further, the impact of repeated electrical loading, with and without preload conditions, is analyzed by examining area strain, energy conversion efficiency, and electrical breakdown strength to evaluate the feasibility of the actuator for real-world applications. The findings reveal that the stresses in the elastomer with reserved strain conditions reduce significantly (about 80%) between the first two cycles and diminish to stabilization with repeated mechanical loading. Also, repeated electrical loading in an actuator made of prestrained elastomer, under preload conditions, is observed to stabilize actuation and improve breakdown strength from 6 to 22 kV. This work demonstrates the importance of considering the preload and prestrain conditions in stabilizing the performance of microporous elastomers, enhancing their reliability for soft actuators and similar electromechanical devices.