Generation of narrow linewidth sidebands by resonant excitation of torsional mode in a microcantilever resonator

Microelectromechanical system (MEMS) resonators are versatile and miniaturized devices capable of resonating at specific frequencies for numerous technological applications. Quality (Q) factor and frequency stability are two critical parameters that determine the performance of MEMS resonators. A higher Q-factor typically translates to narrower resonance peaks, leading to improved sensitivity in sensing applications. Frequency stability, on the contrary, refers to the ability of a resonator to maintain its operating frequency over time and under varying environmental conditions. We explore in this study the feasibility of improving the linewidth and the frequency stability of a microcantilever resonator through resonant excitation. We discover that parametric excitation enables mode coupling between its first torsional mode, ft, and the second flexural mode, f2, and generates two resolved sidebands. The sidebands exhibit narrow linewidths and improved frequency stability over the two original modes, with tunable frequency capacity that can be achieved by adjusting the excitation voltage. This approach offers a versatile method for the design of highly stable MEMS resonators in practical applications.