Chip-scale aerosol impactor with integrated resonant mass balances for real time monitoring of airborne particulate concentrations

This work presents chip-scale integration of MEMS resonant mass balances along with aerosol inertial impactors (airborne micro/nanoparticle collectors). A three mask microfabrication process has been developed to produce the main components; mass balance, impactor nozzle, and impaction micro-chamber on a single SOI substrate. In addition to extreme miniaturization of a conventionally bulky setup and allowing real-time particulate mass concentration data collection, this approach addresses assembly challenges for discrete versions of such systems, e.g. misalignment between MEMS resonators and nozzles. Furthermore, small nozzle diameters achievable through microfabrication, minimizes the air flow and therefore pump capacity requirements.