ACES characterization of damping in micro-beam resonators

This study develops a preliminary model of Q-factor of MEMS resonators by using Analytical, Computational, and Experimental Solutions (ACES) methodology to investigate the effects of various damping mechanisms on the Q-factor of microelectromechanical resonators. Focus was made on the contributions of air damping, thermoelastic damping (TED), and surface damping to the Q-factor. Laser Doppler Vibrometry (LDV) and Michelson Interferometry were used to characterize the damping of tipless atomic force microscopy (AFM) probes through ring down tests. Tests were performed at various levels of vacuum with different beam geometries and coatings. COMSOL was used to model the TED as well as resonance characteristics of the beams and the computational results were compared to analytical and experimental results. It was found that as surface area to volume ratio increases beyond approximately 1 μm−1, surface damping becomes the dominant damping mechanism. Additionally air damping was significant at a vacuum level gr...