Other Research
- Q-factors of Nano and Micro Scale Oscillators (R.B. Bhiladvala and Z.J. Wang, Phys. Rev. E 69, 036307 (2004) [PDF]) Oscillating beams at micron and nano scales can potentially be used as detectors of small masses such as biological cells. The quality of a detector depends on the damping in the system. In collaboration with research groups at Cornell Center for Material Research, we investigated the effects of air damping on a small oscillating beam at high frequency, typically, 108 Hz. Because of high frequency, the usual Stoke's drag has to be replaced by the unsteady Stoke's drag in the continuum limit. In addition, at these small scales, the continuum limit breaks down at various pressure for a given size. We calculated Q-factors as a function of pressure over the range from 10-5 torr to 105 torr, which covers free molecular, cross-over, and continuum regimes. While it is advantageous to use micro-scale beam in the low pressure limit, use of nano-scale beam becomes advantageous above a cross-over pressure.