Design optimization of polymeric Out-of-plane electro-thermal actuator

In this paper, we report the design, simulation and optimization of a novel polymeric out-of-plane electro-thermal micro-actuator. The electro-thermal micro-actuator consists of tri-layers: the passive Ni layer, an expanding SU-8 layer and a curling S-shaped Ni heater. The tri-layer actuator is accompanied with a suspended structure to produce an out-of-plane movement perpendicular to the substrate, under a pulse current. Firstly, this proposed device is advanced. By means of FEA (finite element simulation with ANSYS™), the geometric structure is optimized and the electro-thermal capabilities are determined theoretically. The simulation shows the actuator can obtain the best capabilities, when the thickness of actuating SU-8 layer is 12μm; the thicknesses of the heating layer and passive Ni layer are all 4μm.