Optomechanics for NEMS based Mass Spectrometry

Nanoelectromechanical systems (NEMS) provide an ideal platform for single molecule sensing applications due to their minute size and high quality factors. One application is the measurement of the mass of individual adsorbed molecules, such as single proteins. The mass resolution is governed by the uncertainty in the measured resonance frequency, with contributions from the mechanics (e.g thermomechanical noise), readout circuitry noise, and the intrinsic instability of the resonator. As a result, a detailed understanding of phase noise is necessary for improved sensor performance. Here we detail a new scheme for NEMS mass sensing based on superconducting microwave cavity optomechanics. The optomechanical transduction scheme is expected to improve the phase noise and resulting mass resolution of NEMS sensors.