Long‐Life‐Cycle and Damage‐Recovery Artificial Muscles via Controllable and Observable Self‐Clearing Process

Abstract

Dielectric elastomer actuators (DEAs) exhibit a collection of excellent performances to be the next‐generation artificial muscles, yet they suffer from short lifespan and premature breakdown. Self‐clearing of defects from thin, compliant electrodes can potentially solve these problems, yet this process is currently neither observable nor controllable. Herein, a dimensionless indicator named capacitor retention is proposed to indicate the remaining capacity to generate force/displacement of a DEA during self‐clearing. This indicator can be conveniently monitored during the short‐term and long‐term degradation of the actuators with different configurations and different driving modes. Based on this indicator, DEAs’ dielectric strength is redefined. With the assistance of scalable manufacturing of multilayered DEAs, several key factors that affect the conditions under which the self‐clearing phenomena occur, as well as how they affect the dielectric strength of the actuators, are investigated. Finally, through self‐clearing preprocess, using appropriate combinations of factors derived from the earlier investigations, high‐performance DEAs with unidirectional strain of 9.4%, power density of 301 W kg−1, >1 million life cycles at a resonant frequency of 125 Hz, and the ability to recover from multiple times of external damages are achieved. This work can potentially produce long‐life and highly robust artificial muscles for DEAs’ future applications.