Development of Pneumatic Rotary Soft Actuator.

Abstract

A soft actuator with an inherent flexibility has been required to build up a soft mechanical drive system such as a human collaboration robot. In this study, a rotary type soft actuator made of silicone rubber driven with a compressed air has been developed. This actuator can realize the desired rotary operation by using the fiber reinforcement and the partial difference of stiffness owing to the rubber thickness. In this paper, the structure and operation principle of the actuator is described, and fundamental properties of actuator are experimentally investigated. the experimental results show that the actuator has the sufficiently large operational angle and the dynamic characteristics of a damping the elasticity component. Its application to a soft robot finger and a robot hand are discussed. Owing to the flexibility of actuator, this hand can grasp unshaped or flexible objects without any complicated control algorithm. The availability of this actuator is confirmed through some experiments.