Thermally actuated MEMS resonant sensors for mass measurement of micro/nanoscale aerosol particles

This work presents thermally actuated micro-electromechanical resonant sensors capable of measuring the mass of micro/nanoscale aerosol particles deposited on them. The resonators were specifically designed for maximum tolerance of air viscous damping and deposited particles and were fabricated using a single-mask fabrication process on SOI substrates. The fabricated resonators were placed in a custom-made aerosol particle collection and deposition system. We have successfully shown up to 6 kHz (0.33%) shift in resonance frequency resulting from the particle mass loading. Sensor sensitivities are calculated to be in the order of hundreds of Hz/ng. The sensors presented in this work offer the prospect of implementing miniaturized and low-cost instruments for air quality monitoring and environmental research.