Air damping of mechanical microbeam resonators with optical excitation and optical detection

This paper is dedicated to both Finite Element Method (FEM) simulations and optical measurements of the mechanical quality factor dependence on air pressure of microbeam resonators. Firstly, a summary of previous theoretical works is given, for two different air cavity cases. Different damping mechanisms are discussed. Secondly, FEM simulation results using MEMCAD software are obtained for resonators with small air gaps. Finally, prototypes of silicon resonators are fabricated using SOI technology, and characterized under a precisely controlled vacuum chamber. In order to investigate both air cavity cases, optical excitation/detection is used. Good agreements are obtained with theory and simulations.