Vacuum Effect on Electromechanical Properties of Dielectric Elastomers: A Preliminary Study

Abstract

Environmental factors, such as temperature, humidity, and other external conditions, have a significant impact on the electro-induced deformation behavior of dielectric elastomers. Aiming at the potential application of dielectric elastomer driving structure in space exploration, the electromechanical deformation of dielectric elastomers in the vacuum environment is preliminarily investigated in this work. Firstly, the dielectric constant of VHB4905 was measured. Then, the vacuum effect on electromechanical behaviors of dielectric elastomers was characterized, including the electromechanical deformation, response, and viscoelastic creeping. The failure mode and stability of dielectric elastomer were also analyzed in detail. In the vacuum environment, the deformation of the dielectric elastomers decreases and the response speed becomes slow under the same voltage. There is a significant improvement in electromechanical breakdown voltage, maximum deformation capacity, and stability. In addition to the common failure phenomena such as electromechanical breakdown, film tearing, and wrinkling, new failure modes were observed under vacuum conditions, including external electric field breakdown and leakage current failure. Finally, the dynamic response characteristics of dielectric elastomers were examined, with results indicating that the material's inherent viscoelasticity has a far greater influence on dynamic behavior than the vacuum conditions. The results provide insight into the design of dielectric elastomer-based soft robots and actuators, particularly for applications in space exploration.

Keywords: Dielectric elastomer actuator, vacuum, electromechanical breakdown, stability