Strain-amplified electroactive polymer actuator for haptic interfaces

Abstract

The demand for actuators featuring biomimetic properties such as direct drive, high power density and intrinsic compliance is growing in robotics and bioengineering. Our work is aimed to increase the performance of a class of actuators utilizing active polymer components which are characterized under several different electrical stimulation conditions. In order to increase the active strain of the system we have considered a configuration inspired to McKibben muscle. In this configuration each active element is covered by a braid mesh shell (made with flexible, but not extensible, threads), which contracts when the element increases its volume. This technical solution amplifies the strain up to 50 times and can be utilized to reach tangible shortening of the actuator.