Static and Dynamic Amplification Using Strong Mechanical Coupling

Amplifying the signal-to-noise ratio of resonant sensors is vital toward the effort to miniaturize devices into the sub-micro and nano regimes. In this work, we demonstrate theoretically and experimentally amplification through mechanically coupled microbeams. The device is composed of two identical clamped-clamped beams, made of polyimide, connected at their middle through a third beam, which acts as a mechanical coupler. Each of the clamped-clamped microbeams and the coupler are designed to be actuated separately, hence providing different possibilities of actuation and sensing. The coupled system is driven into resonance near its first resonance mode and its dynamics is explored via frequency sweeps. The results show significant amplification in the resonator’s amplitude when the signal is measured at the midpoint of the coupler, compared to the response of the individual uncoupled beams. The static pull-in characteristics of the system are also studied. It is shown that the compliant mechanical coupler can serve as a low-power RF switch actuated at low voltage loads.