Self-sustained micromechanical resonant particulate microbalance/counters

This work presents the technological basis for implementation of MEMS-based air-borne particulate counters capable of simultaneous mass measurement of individual particles. Self-sustained thermal-piezoresistive micromechanical oscillators with frequencies in the few MHz range have been used as high-precision microbalances eliminating the need for supporting analog circuitry. Mass sensitivity of the sensors were measured using artificially generated aerosol particles to be in the 10-30 Hz/pg range allowing detection and mass measurement of individual particles with submicron diameters.