Design of an Accordion-Fold-Inspired Soft Electrohydraulic Actuator for Angular Motion

Angular motion of soft actuators is important for utilization in robotic systems. In the robots, the angular motion should enable agile movement and a wide range. This study proposes a novel design of a soft electrohydraulic actuator inspired by an accordion with an improved angular deformation range. The actuator generates instantaneous hydraulic force and achieves a fast response within 0.15 s upon activation. Furthermore, the accordion-fold structure of the actuator induces large rotational deformations of 171 degrees. We conduct a series of experiments to investigate the angular motion characteristics from the geometrical parameters of the actuator. Additionally, based on the experimental results, we demonstrate how to apply electrohydraulic actuators to animate objects.