Numerical study of bimetallic actuated micro-membrane with large deformations

This paper presents a new method to better predict bimetallic thermally actuated membrane behavior in micro-electro-mechanical systems based on finite element method simulations. Unlike previous approaches, this new method includes heat transfer analysis to evaluate the temperature distribution under definite power actuation. Large deflection behavior (larger than one half of the membrane thickness) is predicted from the evaluated temperature distribution and additional applied pressure. Ultra-thin membranes for high displacements have been fabricated using an IC-compatible process flow. Their thermal and mechanical characteristics are compared with simulation predictions. The results under pressure show a lower than 4% difference between experiments and theoretical predictions.