Design and analysis of novel micro displacement amplification mechanism actuated by chevron shaped thermal actuators

摘要

This paper presents design and analysis of microelectromechanical system (MEMS) based displacement amplification mechanism actuated using thermal actuators with enhanced performance. The proposed model consists of chevron shaped thermal actuators, an amplification mechanism capable of amplifying displacement 20 times and an electrostatic comb drives for sensing displacements. When voltage is applied to thermal chevrons, displacement is produced which is then amplified 20 times. Steady state static thermal electrical analysis is performed under variable resistivity and voltage bias of 2V. In-plane reaction forces of magnitude 194.2 and 150.91 mu N along X and Y-axis, respectively, thus producing displacement of 0.11 and 2.22 mu m along X and Y-axis, respectively. Time domain simulations of device are carried with constant electrical resistivity, variable voltage and convective boundary conditions. Modal analysis of the mechanism is carried out to predict the natural frequencies and associated mode shapes of mechanism during free vibrations. The desired mode is at frequency of 286.160kHz. Dynamic simulations including direct integration-transient, transient modal and steady state modal analysis are performed on the device for time span of 0.0006s, under application of 25g and frequency range of 200-300kHz. Simulation results prove the viability of the mechanism as an amplification device with enhanced voltage-stroke ratio.