Miniature Environmental Air Sampler Using Aerogel for Biological Material Collection and Fluid Reduction

Sensors exist to detect biological warfare agents and to provide an early warning so that precautionary and countermeasures can be implemented if necessary. Current assay technology is capable of detecting quantities of bacteria, viruses, and toxin molecules to levels as low as 10-12g. Introduction of the collected material into some assay devices requires sample reduction to liquid phase. An advanced material called aerogel will be investigated for utility in an automated collection subsystem. In terms of aerodynamic filtration efficiency, aerogel has outstanding potential due to its nanometer-size pore structure. The porosity of aerogel reaches 99.8% which could produce an ultra-low pressure drop that directly reduces power consumption. The inner surface area of this material is approximately 1600 m2/g and it may be possible to treat it with reactants to enhance the entrapment of biological agents. The most applicable property for this research is that aerogel can be made either hydrophilic or hydrophobic. This allows easy reduction of the collected sample to liquid phase with a simple aqueous process. Phase I research will focus on measuring the fundamental filtration/collection properties of aerogel followed by several baseline collection subsystem designs.