Towards electroactive gel artificial muscle structures

Polyvinyl chloride (PVC) gel is a promising, soft-smart material with electroactive properties, which can be used to make soft robotic actuators with impressive characteristics. However, until now, PVC gel actuators have always been made with rigid metal electrodes, preventing the fabrication of fully soft devices. Here, we present a novel conceptual design for PVC gel actuators. By moving the microstructure from the electrode to the gel itself, we enable PVC gels which exhibit linear contraction when sandwiched between planar electrodes made from any conductive material. We investigate four different microstructures, three of which exhibit higher displacements compared with a traditional (mesh-based) PVC gel actuator. The best performing gel achieved a displacement of 26% of the microstructure height. Finally, we demonstrate an entirely soft PVC gel actuator with thin conductive rubber electrodes. This article is a first step towards totally compliant artificial muscles made from soft electrodes and PVC gels.