Shape memory alloy wires as actuators for a minirobot

Shape memory alloys are functional materials with favourable properties as actuating elements. The most important characteristics of these materials are presented, a description of shape memory effect principle is done and the specific operation of shape memory wires is described. Thus, such wire is initially elongated and when is heated over the phase transformation temperature, it will contract with an amount of 3–5% of the length, doing an action. The design of a minirobot actuated by NITINOL wires is marked out. It has four DOFs plus prehension function. The developed prototype is depicted.