Variable impedance due to electromechanical coupling in electroactive polymer actuators

This paper presents a variable impedance suspension system based on electroactive polymer (EAP) actuators, leveraging their inherent compliance and damping, light weight, and low power requirements. We describe the manufacturing process used to create a small, lightweight EAP suspension and a novel control circuit used to vary its properties. Next, we model the electromechanical coupling by which impedance values are changed, and experimentally verify its behavior. Of particular interest is the transient response, for example, as encountered when a robot touches down after jumping or gliding. We conclude with a discussion of the changes in performance that are possible when applying a variable impedance EAP suspension to a small flying and perching robot.