This chapter presents the design, fabrication, numerical simulations and experimental investigations of a polymeric microgripper designed using the cascaded V-shaped electrothermal actuators. The microgripper has a total length around 1 mm and a total thickness of only 20 μm. The microgripper was simulated using electro-thermo-mechanical finite element method (FEM) in order to check the performance of the gripper. As structural material of the microgripper, the SU-8 biocompatible polymer was used during the fabrication process. A fabrication process was implemented to realize the microgripper using a symmetrically sandwich structure. The metallic micro-heaters were encapsulated in the polymeric actuation structure of the microgrippers to reduce the undesirable out-of-plane displacement of the gripper tips and the mechanical stress, to improve the thermal efficiency, and for obtaining the electrical isolation of the structure. Experimental testing has been performed to determine the openings and the temperatures of the microgripper tips as function of electrical current. A displacement of the tips of more than 50 μm can be obtained at an electrical current of around 26–28 mA. A comparison between the simulation results and the measurements were also presented.
Part of the book: Actuators