STTR Phase I: Novel real-time particulate matter (PM) sensor for air quality measurements

The broader impact/commercial potential of this Small Business Technology Transfer Research (STTR) Phase I project will lie in the improved ability to accurately monitor indoor and outdoor airborne particles using the proposed low-cost, broad size-range, aerosol sensor to be developed in this research project. Inhalation of aerosol particles can result in adverse human health effects, with the critical parameter from a health effect perspective being the concentration of particles smaller than 2.5µm, i.e. PM2.5. Measurements of PM2.5 are critical to understand the extent of particulate exposure that populations experience in different environments. This project?s proposed approach is to measure particle concentrations by charging them and sensing their abundance using sensitive low-current circuits. This approach allows for measurements over a broad size range and at low-cost. Most of the currently available aerosol sensors are only sensitive to particles larger than ~ 500 nm, and hence are unreliable for ambient measurements. The proposed sensor will, thus, likely generate a significant interest in the aerosol research community and the ambient air quality monitoring industry. The technical objectives in this Phase I research project are to demonstrate the feasibility of accurate aerosol concentration measurements over a size range of 10 nm to 2.5 µm using an electrical-sensing technique. The intellectual merit of the proposed project lies in the novel combination of electrical-mobility aerosol classification, printed electrodes, low-current sensing electronics, and advanced inversion algorithms to result in a low-cost real-time, wide size-range, aerosol sensor. With printed electrodes, the signal response from the sensor can be tailored to be proportional to total particle volume concentration, and, thus, to PM2.5. The research objectives are to demonstrate the accuracy of volume concentration measurements made with our sensor for a range of particle types and size distributions. The successful completion of this project should result in a prototype sensor that can accurately measure total aerosol concentrations in different ambient conditions. This would be a first critical step towards the final development of a low-cost sensor for large-scale air quality measurements.