Activated Switching in a Parametrically Driven Micromechanical Torsional Oscillator

Parametric resonance and parametric amplification are important phenomena that are relevant to many fields of science. For mechanical systems, parametric driving typically involve modulating the spring constant [1, 2] or the moment of inertia near twice the natural frequency of the system. Parametric amplification has proved useful in improving the signal to noise before transduction of the mechanical displacement into an electrical signal [1]. Apart from amplifying a signal, parametric pumping can also reduce the linewidth of the resonance response, opening up new opportunities for biochemical detection using micro- and nano-mechanical devices in viscous environments [3]. Recently the sharp jump in the parametric response of micromechanical oscillators at subcritical bifurcation was used for accurate determination of the natural frequency to deduce device parameters [4].