Theoretical and Numerical Investigations on a Silicon-based MEMS Chevron type thermal actuator

Abstract

This work aims to understand the thermo-electromechanical behaviour of a silicon-based, chevron type thermal actuator (TA) in microelectromechanical systems (MEMS). The analysis presents simple analytical and numerical models of the chevron type thermal actuator (CTA). The analytical models are compared with the results of finite element models (FEM) to optimise the TA design parameters and validate thermo-electromechanical analysis. Moreover, analytical models for deflection allow for a much easier optimisation and more straightforward design process than with the finite element approach. Since the deflection of chevron thermal actuators depends on many variables, design guidelines are introduced to create an optimum, efficient chevron thermal actuator for the desired deflection under a specified external load. This study shows that the CT A-optimised beam length is 2000 $\mu \mathrm{m}$ and optimised inclination is 5°. Chevron type TA deflection will be 50% less for higher inclination angles greater than those between 5°-10°. The minimum voltage required for the displacement of 3.5 $\mu \mathrm{m}$ is 3.3 V and a power consumption of approximately 3 mW was obtained from this study. This optimised design and thermo-electromechanical analysis can be used to design and investigate the high switching response in a silicon-based chevron type TA.