Mechanical domain coupled mode parametric resonance and amplification in a torsional mode micro electro mechanical oscillator

In this paper, we experimentally demonstrate non-degenerate parametric resonance in a torsional micro electro mechanical (MEM) oscillator with two interacting mechanical modes of oscillation. The parametric oscillation results from a displacement-dependent electrostatic force generated in both the modes of oscillation. There is a decoupling of the input and the output frequencies in this mode of operation where the system responds at the primary natural frequency when driven at the sum of the first two mechanical modes. This can be implemented in many commonly used MEM oscillator configurations including the cantilever beam geometry. In this mode of operation, single oscillator non-degenerate parametric amplifiers as well as resonant mode sensors based on the frequency selectivity of parametric resonance can be implemented.