Chemical Warfare Agent Detection Using MEMS-Compatible Microsensor Arrays

Published

August 1, 2005

Author(s)

Douglas C. Meier, C J. Taylor, Richard E. Cavicchi, Edward White, M W. Ellzy, K B. Sumpter, Stephen Semancik

Abstract

Microsensors have been fabricated consisting of TiO2 and SnO2 sensing films prepared by chemical vapor deposition (CVD) on MEMS- (micro-electromechanical systems) compatible array platforms. Response measurements from these devices to the CW agents GA (tabun), GB (sarin), and HD (sulfur mustard) at concentrations between 5 and 200 nanomoles/mole (ppb) in dry air, as well as to CW agent simulants CEES (chloroethyl ethyl sulfide) and DFP (diisopropyl fluorophosphate) between 250 and 3000 ppb, are reported. The microsensors exhibit excellent signal-to-noise and reproducibility. The temperature of each sensor element is independently controlled by embedded microheaters that drive both the CVD process (375 C) and sensor operation at elevated temperatures (325 C to 475 C). The concentration-dependent analyte response magnitude is sensitive to conditions under which the sensing films are grown. Sensor stability studies confirm little signal degradation during 14 hours of operation. Use of pulsed (200 ms) temperature-programmed sensing (TPS) over a broad temperature range (20 C to 480 C) enhances analyte selectivity, since the resulting signal trace patterns contain primarily kinetic information that is unique for each agent tested.

Citation

IEEE Sensors Journal

Volume

5

Issue

No. 4

Pub Type

Journals

Keywords

chemical vapor deposition, chemical warfare agent, conductometric gas sensor, MEMS, metal oxide film, microhotplate, microsensor

Citation

Meier, D. , Taylor, C. , Cavicchi, R. , White, E. , Ellzy, M. , Sumpter, K. and Semancik, S. (2005), Chemical Warfare Agent Detection Using MEMS-Compatible Microsensor Arrays, IEEE Sensors Journal (Accessed April 23, 2024)