Biomimetic air sampling for detection of low concentrations of molecules and bioagents : LDRD 52744 final report.

Hughes, Robert Clark

Sandia National Laboratories

关键词: Biological Warfare Agents;    Microsensors.;    Silkworm;    Chemical Explosives;    Micromachining-Technological Innovations;   

DOI  :  10.2172/918207
RP-ID  :  SAND2003-4707
RP-ID  :  AC04-94AL85000
RP-ID  :  918207

美国|英语

来源: UNT Digital Library

【 摘 要 】

Present methods of air sampling for low concentrations of chemicals like explosives and bioagents involve noisy and power hungry collectors with mechanical parts for moving large volumes of air. However there are biological systems that are capable of detecting very low concentrations of molecules with no mechanical moving parts. An example is the silkworm moth antenna which is a highly branched structure where each of 100 branches contains about 200 sensory 'hairs' which have dimensions of 2 microns wide by 100 microns long. The hairs contain about 3000 pores which is where the gas phase molecules enter the aqueous (lymph) phase for detection. Simulations of diffusion of molecules indicate that this 'forest' of hairs is 'designed' to maximize the extraction of the vapor phase molecules. Since typical molecules lose about 4 decades in diffusion constant upon entering the liquid phase, it is important to allow air diffusion to bring the molecule as close to the 'sensor' as possible. The moth acts on concentrations as low as 1000 molecules per cubic cm. (one part in 1e16). A 3-D collection system of these dimensions could be fabricated by micromachining techniques available at Sandia. This LDRD addresses the issues involved with extracting molecules from air onto micromachined structures and then delivering those molecules to microsensors for detection.