A Novel Micromechanical Mode-Localized Resonator Utilizing Anti-Resonating Structures

A novel micromechanical mode-localized resonator has been demonstrated. In particular, a CMOS-MEMS clamped-clamped beam resonator topped with multiple cantilevers that serve as anti-resonating tuned-mass dampers yields a resonance frequency variation of 0.14% for an equivalent mass perturbation of one picogram added on the cantilever beams, resulting in a sensitivity as high as 10× compared to that simulated without the anti-resonating structures. Additionally, the pg-mass perturbation yields a variation of 2.93% in the magnitude of the frequency response of the presented mode-localized sensor, whereas the regular resonator exhibits nearly zero change. Unlike typical 2-degree-of-freedom mode-localized sensors that couple two identical resonators, this approach boosts the effect of mass perturbation by miniaturizing the secondary oscillating tank, which serve as the absorbers. Via the unbalanced coupling scheme, a larger percentage change in mass for a certain mass perturbation can be achieved, thereby resulting in a higher sensitivity.