Shipping Container Remote Sensing

There is a large and growing demand for chemical sensors in various uses, including sensitive detection of chemical warfare agents, detection of gas leaks of various sorts, air quality monitoring, and to monitor various chemical processes. As chemical sensors become less expensive, less obtrusive, and more readily networked for computer control, they will become ubiquitous in sensing and controlling many processes ranging from chemical creation to traffic control. We propose to fabricate a MEMs-based quadrupole mass spectrometer that can offer chip-level integration with power supplies and control logic, that would be small enough to place in almost any system with minimum perturbation, and that should offer high sensitivity and high rejection of cross-talk with other species. These systems should be smaller than 1 cm3, weigh less than 20 g, and consume only a few watts. The density of mass spectrometers available permits us to simultaneously search for many species and use the results to reject any residual cross-talk that might exist. In particular, by checking various mass ratios we can unambiguously separate signals from O2, Cl2, NH3, I2, or H2O2. The ubiquity of such systems will permit widespread deployment of "artificial noses" of high sensitivity to monitor chemical distribution levels.