Mass Tuning in Weakly Coupled Low-Q Piezoelectric MEMS Resonator Arrays for Particulate Sensing

This paper reports the achievement of a mass balanced condition in a low-Q weakly coupled MEMS resonator array for ultrafine aerosol particulate sensing. The mass balancing technique enables the lifetime extension of such real-time particulate sensors without employing any wet or dry-cleaning techniques to remove particles from the resonators. This mass balancing is demonstrated for both the flexural and bulk modes of the same coupled resonator array occurring at ∼54kHz and ∼2.53MHz, respectively. This system also demonstrates for a degree of passive environment immunity to temperature effects by using an amplitude ratio output metric. The Q factor of the coupled MEMS resonator system do not degrade substantially with increased particulate loading.