Friday, 4 November 2005 - 8:00 AM
593a
On-Chip High Speed Gas Chromatograph (Gc) with Carbon Nanotube Sensors
Adarsh D. Radadia1, Richard I. Masel
1, Michael S. Strano
2, Mark A. Shannon
3, and Keith Cadwallader
4. (1) Chemical and Biomolecular Engineering, University of Illinois, 600 S. Mathews St., Urbana, IL 61801, (2) Chemical and Biomolecular Engineering, University of Illinois, Urbana-Champaign, 600 S. Mathews, Urbana, IL 61821, (3) Univeristy of Illinois at Urbana-Champaign, 122 MEB, 1206 W. Green St., Urbana, IL 61801, (4) Food Science & Human Nutrition, University of Illinois at Urbana Champaign, 202 ABL, 1302 W Pennsylvania, Urbana, IL 61801
A micro-GC allows for small, handheld, low power equipments with on-chip devices for environmental sampling. In order to use a micro-GC as a fast chemical warfare agent scanner in highly industrious places like airports, there is a definite need for reduction in analysis times from the current state of the art. Current technology cannot scan (separate and detect) air samples in relatively short times (~ 4 seconds). High speed analysis GC requires 1) a continuous sampling part , 2) a preconcentration part, 3) micro-columns with high separation efficiency and resolution ability and 4) a detector with fast analysis time.
We use standard microfabrication techniques to create each of the components and test individual performance. Integration of the fabricated parts will not be demonstrated. A MEMS pump with a fluctuating polyimide membrane is fabricated to form the continuous sampling component of the GC. Preconcentration principle is demonstrated in a microfluidic processor with valves using metal-organic framework molecules as the adsorbing species. Micro-columns are fabricated in silicon using DRIE technique. High resolution columns are fabricated after studying effects of 1) various micro-channel bend geometries and 2) micro-channel configurations on chip. The detector side effort is focused on building a carbon nanotube based chemi-sensors. Carbon nanotubes are highly promising materials for sensing chemical species like thionyl chloride and dimethylmethylphosphonate, a simulant for chemical warfare agent sarin. Results of individual operational components are evaluated using an ordinary modified GC.
See more of #593 - Topical Sensors: Design, Fabrication and Application of Microsensors I (T5002)
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