SBIR Phase II: Development of Particulate Mass and Count Monitoring Instruments Using Micro-Electro-Mechanical Resonant Balances

This Small Business Innovation Research Phase II project aims to develop small size, light-weight, and affordable personal particulate matter (PM) dosimeters. The targeted battery powered instrument almost the size of a fountain pen can be clipped onto clothing and freely carried around. The instrument can sample the surrounding air, separate airborne particles into several size ranges, and measure the mass of particles collected from the air sample in each size range. The instrument is comprised of a miniaturized cascade impactor with micro-electromechanical resonant balances embedded within, as impaction substrates. The cascade impactor configuration separates airborne particles based on their size and deposits them onto the resonant balance surfaces. Added mass of the deposited particles causes a negative shift in the resonant frequency of the microscale resonant balances. Integrated electronics within the system measure the resonator frequency changes and calculate the deposited mass and consequently PM concentration in the air flow in real-time. Development of such instruments would be a major leap forward, not only in aerosol science and technology, but also in microsystems technology. This product would be the first commercial product using a microscale mass balance in a sensory application and could open the door to other possibilities. The broader impact/commercial potential of this project is in industrial hygiene for high dust work environments such as coal mines, underground construction sites, stone and wood cutting facilities, etc. Aerosol particles in the diameter range of a few microns and below pose serious threats to human health. While larger particles are filtered out by human nose and throat, finer particles can reach deep into the lungs and even other organs through the blood stream. It is well established that exposure to high particulate matter concentrations increases risk of various chronic diseases, lowers life expectancy, and in extreme cases leads to severe untreatable conditions such as Silicosis. Currently available particulate monitoring systems cannot address the need for a versatile, convenient, highly portable PM monitor. More importantly, the convenience, affordability, and versatility of the instrument allow tighter monitoring of PM levels and protecting every individual worker from harmful PM exposures. This could be a lifesaver for millions of workers in high risk environments.