Understanding fundamental trade-offs in nanomechanical resonant sensors

Nanomechanical resonators are used as high performance detectors in a variety of applications such mass spectrometry and atomic force microscopy. Initial emphasis nanomechanical resonant sensor research was on increasing the sensitivity to level single molecule, atom beyond. On other hand, there where speed detection is crucial, prompting recent works that emphasize sensing schemes with improved time resolution. We first develop general modeling framework encompassing all resonator tracking currently use, by extending previous work. then explore fundamental trade-offs between accuracy three architectures, namely feedback-free open-loop approach, positive-feedback based self-sustaining oscillator, negative-feedback frequency-locked loop scheme. comparatively analyze them unified manner, clarify some misconceptions seem exist literature, unravel their versus characteristics.