Nonlinearity-assisted frequency stabilization for nanowire array membrane oscillator

The sensitivity of a micro/nano-scale mechanical mass sensor is limited by its frequency stabilities, which are affected by various frequency noises. Typically, device nonlinearity is intentionally avoided, because higher amplitude fluctuations in the nonlinear region could be translated into frequency variability. Here, we successfully used damping nonlinearity bifurcation to stabilize a mechanical membrane oscillator frequency to 0.04 ppm, a reduction by two orders of magnitude over that from linear motion. This method presents a general mechanism for oscillation frequency stabilization. We recently presented a DNA mass sensor with femto-molar sensitivity - coupled with the result in this paper, the sensitivity of the mass sensor could be improved by a factor of two orders of magnitude.