Design of a microgripper for micromanipulation of microcomponents using SMA wires and flexible hinges

For this study, a simple and easily manufacturable microgripper was designed utilizing shape memory alloy (SMA) wire. First, a microgripper with flexible hinge structures was designed to enable the fine handling of micro parts. The structural design of the microgripper was refined by repeated FE analyses. The characteristics of its major components, including SMA wire and a strain gauge, were investigated by experiment, and on the basis of the results, a controller was designed and fabricated for the control of the gripping force of the microgripper. In addition, the PI control gain of the controller was determined by considering the characteristics of the SMA wire, which has hysteresis response characteristics to heating and cooling. Gripping force control testing was conducted using the fabricated microgripper and a PI controller, in order to verify the performance of the designed microgripper.