Characterization of a Laterally Oscillating Microresonator Operating in the Nonlinear Region

Microresonators are popular structures used in a variety of applications. They generally operate in the linear region where the vibration amplitude is limited, thereby limiting the signal-to-noise ratio. The nonlinear vibration region, where amplitudes and, consequently, the signal-to-noise ratio are relatively large, is generally avoided owing to instabilities and complexities in analysing the vibrations. In this work, a nonlinear dynamic model with a damping constant obtained from Monte Carlo simulation was derived to describe the vibration responses of microresonators operating in the nonlinear region. A laterally oscillating comb-drive driven resonator was designed, fabricated and characterized at various pressures and driving signals to validate the model. A simple method to extract the quality factor of the resonator in the nonlinear region was also proposed. The measured quality factors were compared with those obtained from the nonlinear model and a good agreement was obtained.