A multi-electrode electroelastomer cylindrical actuator for multimodal locomotion and its modeling

Abstract

Dielectric elastomer actuators (DEAs) have received widespread attention in human-robot interaction and biomedical engineering due to their merits of large deformation, fast response, and excellent biocompatibility. The cylindrical DEA is one of the preferred structures, combining flexibility and compactness. However, the inherent non-linear behavior between the voltage and the actuator makes predicting the output performance during the design process difficult and encumbers its application, especially for multiple degrees of freedom. Herein, a dielectric elastomer spring-roll bending actuator capable of multimodal spatial locomotion using three pairs of electrodes is proposed in this paper. The electromechanical coupling behavior of the actuator under unidirectional bending deformation is described by analyzing the stress process between the spring and the film. The system's damping and excitation frequency relationship is obtained via a semi-analytical method. The experimental results validate the actuator design and show good consistency with the theoretical model. A prototype soft robot capable of running and turning is successfully demonstrated. The actuator also achieves various spatial trajectory paths via the cooperation between electrodes. Thus, the proposed scheme and modeling shed new light on the design and control of dielectric elastomers for multimodal deformation.