A Monolithically-Integrated μGC Chemical Sensor System

Gas chromatography (GC) is used for organic and inorganic gas detection with a range of applications including screening for chemical warfare agents (CWA), breath analysis for diagnostics or law enforcement purposes, and air pollutants/indoor air quality monitoring of homes and commercial buildings. A field-portable, light weight, low power, rapid response, micro-gas chromatography (mu GC) system is essential for such applications. We describe the design, fabrication and packaging of mu GC on monolithically-integrated Si dies, comprised of a preconcentrator (PC), mu GC column, detector and coatings for each of these components. An important feature of our system is that the same mechanical micro resonator design is used for the PC and detector. We demonstrate system performance by detecting four different CWA simulants within 2 min. We present theoretical analyses for cost/power comparisons of monolithic versus hybrid mu GC systems. We discuss thermal isolation in monolithic systems to improve overall performance. Our monolithically-integrated mu GC, relative to its hybrid cousin, will afford equal or slightly lower cost, a footprint that is 1/2 to 1/3 the size and an improved resolution of 4 to 25%.