An Electro-Thermal Microgripper with Both Closing and Opening In-Plane Movement of the Arms

The paper presents the design, simulations, manufacturing and characterization results of an SU-8 microgripper with in-plane double action of the arms in order to obtain a double XY movement, for opening but also for closing the tips. The microgripper is electro-thermally actuated using three pairs of chevron actuators, two for closing the arms and only one for opening the tips. The microgripper was numerically analyzed using the finite element method and the Coventorware software in order to determine the electro-thermo-mechanical behavior. The fabrication is based on SU-8 polymer as structural material and Au for the heaters. Characterizations were performed in order to investigate the double action (open and close) of the microgripper tips. The measurements show a maximum in-plane opening of the microgripper tips of similar to 72 mu m for an electrical current of 61 mA, and a closing of the arms up to 19 mu m at 121.7 mA.