Fabrication of an electro-thermal micro-gripper with elliptical cross-sections using silver-nickel composite ink

This paper proposes a rapid fabrication process for miniaturized electro-thermal grippers by using silver nickel composite ink. Thick resistive structures are dispensed on a silicon wafer by a dispenser, and the parameters of the dispenser can be controlled for different thicknesses of hot and cold arms in a micro gripper. The fabricated single layer structures are almost symmetric about a central plane of symmetry, thus largely suppressing the out-of-plane deflection. Due to cross-sectional area difference of the cold and hot arms, the micro-gripper can be driven by applying dc voltages. Electrical and mechanical behaviors of the micro-grippers are simulated and tested, and the simulation results are in accordance with the experiment results. The simulated maximum temperature is 155 degrees C, and occurs at the hot arms with an input voltage of 1.54 V. The measured displacement of the micro-gripper is observed to be 311 mu m for an applied current of 0.26A with maximum power dissipation of 0.4W. The fabricated micro-gripper can grip a small styrofoam ball with a diameter of 1.3 mm between both tips. (C) 2016 Elsevier B.V. All rights reserved.