A new inter-phalangeal actuator for dexterous micro-grippers

Abstract

This paper presents a shape memory alloy (SMA) actuator aimed to be integrated in the phalanx of a dexterous micro-gripper. Its original design mechanically decouples motion transmission from force transmission. After a brief discussion on the operating principles of the actuator, the kinematics of the mechanism and its general features are specified. A thermo-mechanical model of the SMA fibers dynamics is then derived from an experimental analysis. Based on this model, a rational design methodology is proposed for the actuator. The last part of the paper shows experimental results. A prototype has been developed using the proposed design methodology. The paper shows the open loop results of this device. Additionally, a position switching mode controller is designed to improve precision and robustness.