Portable Sensor for Airborne Nano-Materials

ABSTRACT: Proposed is a miniature sensor for real time measurement of nano-particle number concentration, surface area and size distributions, and for time- and size-resolved collection of these particles for off-line analysis. This instrument combines two novel technologies: (1) a self-sustaining laminar-flow water condensation particle counter and collector developed by our firm and (2) the opposed migration aerosol size classifier developed at the California Institute of Technology. The self-sustaining water condensation counter provides single particle detection, does not require liquid fill reservoirs, and can be operated in any orientation. This condensation technology also provides concentrated particle deposit that is amenable to elemental or chemical analysis. The opposed migration aerosol classifier provides particle size-selection based on electrical mobility in an inherently more compact form than commercial mobility size classifiers. Both technologies are compatible with devices small enough to be wearable. This Phase I project aims to demonstrate the precision and accuracy of the combined technology, and that it may be made to be unobtrusive, battery operable and suitable for personal monitoring, reporting nano-particle number concentration, surface area, size distribution, while providing size- and time-resolved samples for off line analysis. BENEFIT: This instrument will provide a means to monitor, on a routine basis, human exposures associated with airborne synthesized nano-materials.