Design and Simulation of a One Degree of Freedom SMA Bundle Actuated Finger

Abstract

–In this paper a bundled shape memory alloy (SMA) actuator is proposed. A 0.15 mm diameter Nickel Titanium based commercially available actuator known as Flexinol® is used to develop a 12-string bundled actuator. Strain characteristics of the bundled actuator are investigated by using a custom-built test rig equipped with load cell and laser displacement sensor. A set of three bundled actuators in a special configuration is proposed for actuation of a one degree of freedom finger. The proposed finger is made from three phalanges, links and pin supports. This configuration results in six distinct positions of the finger. The simulation of the finger is carried out by using a software package known as Working Model® . The joint angles in various positions of the finger are calculated by using strain data of the bundle.