Dielectric Elastomer Spring-Roll Bending Actuators: Applications in Soft Robotics and Design

Soft robotics is an emerging area that attracts more and more attention. The intrinsic flexibility and compliance of soft materials and structures would endow novel functions with soft robots. Dielectric elastomers could deform sustainably subjected to external electrical stimuli and become promising materials for soft robots due to the large actuation strain, low elastic modulus, fast response, and high energy density. This article focuses on the fabrication, applications, and design of the dielectric elastomer spring-roll bending actuators. The actuator with large electrically induced bending angle has been made and demonstrated the applications in flexible gripper and inchworm-inspired soft crawling robot. The basic performance of the gripper and the crawling robot has been characterized. Furthermore, a thermodynamic model has been established to investigate the deformation and failure of such actuators. Comparison between theoretical and test results shows that the model is suitable for the prediction of the performance of the actuator. Then the influence of some design parameters on the performance of the actuator has been analyzed and discussed based on the model. The results could provide guidance to the design and optimization of such actuators for different applications.