Search Results for keyword MEMS

2 Related Projects

  • A MEMS Micro Gas Chromatograph
    The determination of complex mixtures of toxic gases and vapors remains a challenging analytical problem of critical importance in human exposure assessments, industrial emission monitoring, biomedical surveillance and diagnosis, and homeland security. To address this problem, we are developing a wireless MEMS micro-GC (uGC) that includes a sample inlet with particulate filter, passive calibration-vapor source, multi-stage preconcentrator/focuser (uPCF), dual-column separation module with pressure- and temperature-programmed separation tuning, an array of microsensors for analyte recognition and quantification, system pressure and temperature sensors, and a vacuum pump and valves to direct sample flow. The ultimate goal is a high-performance micro-instrument that occupies only 1-2 cm3, operates on a few mW average (battery) power, provides simultaneous determinations of complex vapor mixtures at low- or sub-part-per-billion (ppb) levels in a few minutes, has an embedded controller, and can be remotely controlled and interrogated through an RF-MEMS wireless communication link. Recent progress has produced our so-called "Gen-0.5" prototype whose key analytical components are shown above. Tradeoffs in system performance are being characterized and used to guide design revisions being incorporated into the smaller and more highly integrated Gen-1 prototype also shown above. This work is funded by the Engineering Research Centers Program of the National Science Foundation under Award Number EEC-9986866.

  • Designed Materials for an Integrated Vapor Preconcentrator
    This project seeks to specify the optimal quantities and types of high-surface-area adsorbent materials for the u-preconcentrator/focuser (uPCF) module of the WIMS uGC, and to define the optimal operating conditions for the uPCF.

1 Related Group

  • Zellers Lab - Integrated Environmental Microsystems
    The assessment of human exposure to complex mixtures of natural and anthropogenic chemicals ranks among the most important global environmental health challenges. Our ability to meet evolving needs in this area relies critically on innovations in exposure science and technology. Advances that facilitate accurate, high-resolution measurements are integral to mankind's efforts to unravel the intricate relationships between exposure and the risks of adverse health effects, and to minimize such risks.Professor Zellers' research and teaching interests lies at the intersection of Environmental Health Science, Chemistry, and Engineering. His work deals with the fundamental and applied aspects of exposure science and technology and contributes to the broad goal of developing the means to quantitatively analyze complex chemical mixtures of arbitrary composition in field settings.

1 Related Research Area

  • Lab On A Chip
    Increasing evidence suggests that the number of vapors that can be simultaneously recognized and differentiated with standalone sensor arrays is limited and that quantitative analyses of even moderately complex vapor mixtures requires coupling the microsensor array to an upstream GC separation stage. For detecting low analyte concentrations, preconcentration may also be required, particularly for applications in monitoring indoor air-quality (IAQ), ambient environmental contamination, breath biomarkers of exposure/disease, and explosives detection in airports or other public places, where target-vapor concentrations are typically in the low- or sub-part-per-billion range.

    Therefore, the integration of microsensor arrays with micromachined preconcentration and chromatographic stages to create uGC systems capable of analyzing complex vapor mixtures of arbitrary composition is being actively explored. Such integration can lead to a synergy of components capabilities that enhances overall performance. These 'lab-on-a-chip' microsystems are created using Si micromachining, or so-called MEMS technology (MEMS: microelectromechanical systems), and are designed to operate at ultra-low power.