Towards an Ultra Sensitive Hybrid Mass Sensor Based on Mode Localization without Resonance Tracking

Abstract

We present a mode localized mass sensor prototype based on a hybrid system excited at a fixed frequency slightly below the resonances. Indeed, we show, both theoretically and experimentally, that this condition yields higher sensitivities and similar sensitivity ranges than that of resonance peak tracking while being less time consuming than a classical open-loop configuration due to the absence of frequency sweep. The system is made of a quartz resonator and a hardware that includes a resonator and the coupling. The digital aspect allows maximum sensitivity to be achieved with a fine tuning of the different parameters and the implementation of a coupling, regardless of the physical resonator geometry. This allows the generation of mode localization on shear waves resonant structures such as the quartz cristal microbalance widely used in biosensing. This solution has been successfully implemented using resin micro balls depositions. The sensitivities reach almost their maximum theoretical values which means this fixed frequency method has the potential to reach lower limit of detection than the open loop frequency tracking method.

Design and dynamic analysis of a highly sensitive MEMS gyroscope based on mode localization

“…Recently, to significantly improve the sensitivity of MEMS sensors, the mode localization effect of weakly coupled resonator systems (WCRS) has attracted a lot of attention [14][15][16]. Mode localization is a physical phenomenon that occurs in periodic structures [17].…”

Enhancing the linear dynamic range of a mode-localized MEMS mass sensor with repulsive electrostatic actuation

“…For MEMS sensors, the authors often investigate the number of coupled resonators [7][8][9], and the use of other kind of resonators and coupling [10,11]. Recently, the coupling between resonators of different physical nature has been proposed [12,13].…”