Funded by NSF
The purpose of this project is development of a new class of micro/nanoscale aerosol particle sensors. Both electrostatic resonant mass sensors and piezo-resistive impact (momentum) sensors were previously fabricated using micromachining techniques on silicon-on-insulator (SOI) substrates. After our groups’ novel ideas on thermally actuated resonators, we have been utilizing them as mass sensors for measurement of aerosol particles. These resonators are specifically designed for maximum tolerance of air viscous damping and deposited particles and are fabricated using a single-mask process on SOI substrates. The fabricated resonators are placed in a custom-made aerosol particle collection and deposition system. We have successfully shown shift in resonance frequency resulting from the particle mass loading.
Recently sensor sensitivities as high as 1.5 KHz/pg have been calculated which has enabled us to detect and measure individual single 1 micron airborne particles. Theses sensors offer the prospect of implementing miniaturized and low-cost instruments for air quality monitoring and environmental. Further characterization and optimization of the fabricated sensors and also new implementation methods are currently ongoing in the µnX lab.
- E. Mehdizadeh, J. C. Wilson, A. Hajjam, A. Rahafrooz, and S. Pourkamali, “Aerosol Impactor with Embedded MEMS Resonant Mass Balance for Real-Time Particulate Mass Concentration Monitoring,” International Conference on Solid State Sensors, Actuators, and Microsystems (Transducers), 2013.
- A. Hajjam, J. C. Wilson, and S. Pourkamali, “Individual air-borne particle mass measurement using high frequency micromechanical resonators,” IEEE Sensors Journal, vol. 11, no. 11, pp. 2883–2890. November 2011
- B. Harrington, A. Hajjam, J. C. Wilson, S. Pourkamali, R. Abdolvand, “Thin-film piezoelectric-on-silicon particle mass sensors,” IEEE international Frequency Control Symposium (IFCS), 2010.
- A. Hajjam, J. C. Wilson, A. Rahafrooz, and S. Pourkamali, “Fabrication and characterization of thermally actuated micromechanical resonators for airborne particle mass sensing, part II: device fabrication and characterization,” Journal of Micromechanics and Microengineering, Vol. 20, Issue 12, 125019, November 2010.
- A. Rahafrooz, and S. Pourkamali, “Fabrication and characterization of thermally actuated micromechanical resonators for airborne particle mass sensing, part I: resonator design and modeling,” Journal of Micromechanics and Microengineering, vol. 20, no. 12, 125018, November 2010.