Detection and mass measurement of individual air-borne particles using high frequency micromechanical resonators

This work demonstrates detection and mass measurement of single micro/nanoscale air-borne particles using thermally actuated high frequency micromechanical resonators. Single crystalline silicon dog-bone resonators with resonant frequencies in the tens of MHz range were fabricated using a single mask process on SOI substrates. The mass sensitivities of the resonators were characterized using artificially generated airborne particles and mass sensitivities as high as 1.6kHz/pg were demonstrated. Due to the high mass sensitivities, the shift in the resonator frequencies caused by every individual particle is distinguishable. The measured mass sensitivities are in good agreement with the calculated values based on the resonator physical dimensions.