Friday July 1, 2005
Tuesday July 5, 2005

"Room Temperature Operation of a Nanoelectromechanical Resonator Embedded in a Phase Locked Loop"
Mr. Onur Basarir
Boston University

We describe the operation of a phase locked loop (PLL) that tracks the high frequency (HF) electromechanical resonance of a nanoscale beam resonator. The fundamental in-plane flexural resonance of the beam resonator embedded in the PLL is actuated electrostatically and detected optically. PLL operation is demonstrated by locking stably to the resonance frequency of the beam, and by tracking this resonance frequency with high fidelity as the beam is mass loaded. Our numerical analyses explain the observed locking behavior and offer insight into designing more stable circuits. Feedback control schemes for nanoelectromechanical resonators, such as the one presented here, offer prospects for miniature timekeeping devices and ultrasensitive sensors.