Phononic Frequency Combs For Engineering MEMS/NEMS Devices With Tunable Sensitivity
Adarsh V. Ganesan, Ashwin Seshia, Jason J. Gorman
Over the past two decades, MEMS resonators have received considerable attention for physical, chemical and biological sensing applications. Typically, the operation of MEMS resonant sensors relies on the tracking of a resonance frequency using a feedback oscillator. The sensitivity of these sensors is limited by physical parametric variations, as in the Youngs modulus, and noise in the oscillator circuit, such that improvement in the sensitivity can require significant effort in the design, fabrication, ovenization, and control of the resonator. In this paper, we experimentally demonstrate an alternative sensing approach based on a newly documented physical phenomenon, phononic frequency combs, where the sensitivity can be actively tuned by the drive conditions. In addition, the spectral response of frequency combs enables an N+1 fold enhancement in the sensitivity, with 2N+1 being the number of spectral lines associated with a frequency comb.