A Soft Biomimetic Module of Elephant Trunk Driven by Dielectric Elastomers

Compared to rigid manipulators, soft robot has advantages in complex working environments. In this paper, a soft and super lightweight biomimetic elephant trunk is proposed. The biomimetic elephant trunk is driven by dielectric elastomer actuators (DEAs) and operates by the deformation of its structure. To realize a large structural deformation and balance the rigidity requirement, a novel design concept was proposed that is using a group of symmetrical driving actuator areas on the surface of the structure. The relationship between the deformation and the voltage-induced strain was analyzed. Limited by the experimental conditions, only two connected modules were fabricated. However, the output force of the two-module device increased noticeably with the number of DEA film layers; with only three layers of DEA films, the force output reached 41 times its own weight. The experimental results indicate that the module is suitable to make a full-length biomimetic elephant trunk, which has highly redundant degrees of freedom (DOFs).