ANN ARBOR—There’s a bit of magician’s art to what Ted Zellers is trying to do. As he explains it, he and his colleagues are trying to take an instrument the size of a small refrigerator and reduce it to the size of a sugar cube. Zellers, professor of environmental health sciences at the U-M School of Public Health, and his fellow researchers are trying to miniaturize a gas chromatograph—a powerful analytical instrument capable of measuring complex mixtures of volatile organic chemicals at trace concentrations in a matter of minutes. If the project is successful, workers in high-risk occupations ultimately will be able to wear this "MicroGC" as a means of monitoring and protecting them against chemical, and even microbial, exposures. The device also has important implications for homeland security, Zellers says. It’s one of several research projects currently being conducted under the auspices of the Center for Wireless Integrated MicroSystems (WIMS), an Engineering Research Center funded by both the National Science Foundation and a consortium of companies, and designed to serve as a worldwide focal point for work in microsystems. Launched in 2000 and directed by Professor Ken D. Wise of the U-M College of Engineering, the center combines efforts on micro-power circuits, wireless interfaces, sensors and actuators, and wafer-level packaging to create miniature information-gathering modules that can act as bridges to the molecular world. "Essentially, these are smart wireless microelectromechanical systems, or MEMS," said Wise. MEMS technology has widespread potential applications in both electronics and communications. The U-M is the center’s lead university; Michigan State University and Michigan Technological University are partners. The WIMS team plans to unveil a preliminary version of the MicroGC at a meeting this May with the National Science Foundation. As a co-leader of the center’s Sensors and Microinstruments group, Zellers has oversight of the MicroGC effort as well as specific responsibility for several component development efforts. Bench-scale GCs already exist and are widely used in environmental laboratories. Capitalizing on recent advances in microfabrication, Zellers and his colleagues are seeking to build in several unique features to the WIMS MicroGC, such as tunable separations and microsensor-array detection, to make the instrument small and versatile enough for a broad range of applications, from ambient air monitoring to meteorological measurements and occupational health and safety monitoring. A "meso-scale" prototype of the MicroGC has already proved capable of identifying and quantifying the components of mixtures of 30 vapors at part-per-billion concentrations in just 10 minutes. Related web links:

Zellers’ faculty profile page: www.sph.umich.edu/ehs/ih/ih_faculty/zellers.html

Center for Wireless Integrated MicroSystems: www.engin.umich.edu/relations/corporate/ops/erc_wims.html

For more on U-M School of Public Health: www.sph.umich.edu/

www.engin.umich.edu/relations/corporate/ops/erc_wims.html

www.sph.umich.edu/