Volatile organic compounds (VOC's) have been recognized as the principal pollutants in the atmosphere. The U.S. Environmental Protection Agency (EPA) found that almost 50% total estimated lifetime cancer cases could be attributed to VOC's. The specific goal of this Phase I feasibility study proposed here is the development and validation of a novel microsensor breadboard system which will provide a reliable and highly sensitivite monitoring of VOC's. This novel micro gas sensor system will be based on a Micro Electro-Mechanical Systems (MEMS) implementation consisting of an ultra- fast micro Gas Chromatograph (mGC) and an array of optical cantilevers based highly sensitive micro gas sensor. The sensor system will small enough to be wearable or hand carried (size of an iPod), highly efficient, rugged, with an integrated detection and identification system for detection and analysis of Volatile Organic Compounds (VOCs). This proposed device, which will be called VOCAS, will be able detect and accurately analyze VOC's of interest with high specificity at ppm to sub-ppb levels with greatly reduced false positives. Detection levels are better than those of mass spectrometry over a large range of chemicals without the need for a complicated, bulky vacuum system. Our long term goal is to provide a noninvasive, low-profile, near real-time (within 15 seconds), affordable personal environmental exposure monitor platform for monitoring VOC's. This platform, which will be virtually unnoticed by the user for maximum performance and convenience, will provide a rugged, quantitative, reliable, in-field highly sensitive (sub ppb in some cases) measurement of personal-level, point-of-contact exposure to a variety of VOC's of particular interest to health conscious end-users, sports enthusiasts, the immunocompromised, and medical professionals. Integrated Bluetooth communication protocols will be employed to send real-time information wirelessly to a cell phone or PDA. In turn, this information can then be sent wirelessly to online databases for storing and processing information relating personal health with personal environmental factors and user demographics. Key attributes of the VOCS platform include: 1) Vastly increased sensitivity (low ppb), 1-to-2 orders of magnitude superior to current in-situ devices, 2) reduction of false positives due to specificity superior to current in-situ devices, 3) MEMS based chip sized detector module, enabling hand-held/wearable iPod sized field-portable miniature system, and 4) ambient-pressure operation without complicated vacuum systems. We envision that in addition to NIEHS uses, this proposed detector system has several other potential applications such as military uses (detection of many types of explosives and of chemical warfare agents), medical uses (breath analysis), and law enforcement uses (narcotics).
The NIEHS has determined the need for developing and validating new products/devices to improve our ability to precisely measure environmental exposures to individuals utilizing small, field deployable/wearable devices capable of measuring simultaneously and in near real time, multiple agents within a single exposure class such as volatile organic compounds (VOC's). Current detection methods for measuring the concentration of VOC's are inadequate because they require bulky, expensive equipment or off-site spectrochemical analysis. As a joint collaborative effort between a highly innovative small company, Imaginative Technologies (IT) and University of Minnesota (UM) this project will design, and build a breadboard sensor which will be based on a MEMS implementation consisting of an ultra-fast Gas Chromatograph (GC) and a highly sensitive optical array of cantilevers for the detection and identification of VOC's. This unit in breadboard form will be used to demonstrate parts-per-billion for detection and identification of VOCs with about 15 sec response time. This initial development phase will explore the possibility of a sensor platform (including associated data acquisition, logging and communication subsystems) which will be small enough to be wearable/handcarried (size of an iPod), highly efficient, and rugged enough to be used in the field. Cost-effective and accurate monitoring will allow workers to identify and avoid dangerous situations. Integrated data-logging capabilities will provide employers, regulators, and researchers with reliable exposure records.
