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Array-based vapor sensing using chemically sensitive, polymer composite resistors

Lonergan, Mark C. and Freund, Michael S. and Severin, Erik J. and Doleman, Brett J. and Grubbs, Robert H. and Lewis, Nathan S. (1997) Array-based vapor sensing using chemically sensitive, polymer composite resistors. In: 1997 IEEE Aerospace Conference proceedings. IEEE , Piscataway, NJ, pp. 583-631. ISBN 0-7803-3742-5.

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We describe herein the construction of simple, low-power, broadly responsive vapor sensors. Insulating polymer-conductor composites have been shown to swell reversibly upon exposure to vapors. Thin films of polymer composites have been deposited across two metallic leads, with swelling-induced resistance changes of the films signaling the presence of vapors. To identify and classify vapors, arrays of such vapor-sensing elements have been constructed, with each element containing either carbon black or poly(pyrrole) as the conducting phase mixed with one of several different organic polymers as the insulating phase. A convenient chemical polymerization of poly(pyrrole) which allows a high degree of processibility is also described. The differing gas-solid partition coefficients for the various polymers of the sensor array produce a pattern of resistance changes that can be used to classify vapors and vapor mixtures. This type of sensor array has been shown to resolve common organic solvents, including molecules of different classes (such as aromatics from alcohols) as well as those within a particular class (such as benzene from toluene and methanol from ethanol). The response of an individual composite to varying concentrations of solvent is shown to be consistent with the predictions of percolation theory. Accordingly, significant increases in the signals of array elements have been observed for carbon black-polymer composites that were operated near their percolation thresholds.

Item Type:Book Section
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URLURL TypeDescription
Freund, Michael S.0000-0003-1104-2292
Grubbs, Robert H.0000-0002-0057-7817
Lewis, Nathan S.0000-0001-5245-0538
Additional Information:© 1997 IEEE. Date of Current Version: 06 August 2002. This work was supported in part by the Caltech Consortium in Chemistry and Chemical Engineering, the E.I. DuPont de Nemours and Company, Inc. and the Eastman Kodak Company, and by the National Aeronautics and Space Administration and the National Science Foundation, grant CHE-9202583. M.C.L. acknowledges Caltech for an Arthur Amos Noyes Fellowship and B.J.D. acknowledges the Natural Science and Engineering Research Council of Canada for a 1967 Centennial Fellowship and the O'Brien Foundation for financial support. We thank Profs. J.J. Hopfield and J.M. Bower, and the members of their research groups, for helpful discussions.
Funding AgencyGrant Number
Caltech Consortium in Chemistry and Chemical EngineeringUNSPECIFIED
E.I. DuPont de Nemours and Company, Inc.UNSPECIFIED
Eastman Kodak CompanyUNSPECIFIED
Caltech Arthur Amos Noyes FellowshipUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
O'Brien FoundationUNSPECIFIED
Record Number:CaltechAUTHORS:20120126-094442947
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Official Citation:Lonergan, M.C.; Freund, M.S.; Severin, E.J.; Doleman, B.J.; Grubbs, R.H.; Lewis, N.S.; , "Array-based vapor sensing using chemically sensitive, polymer composite resistors," Aerospace Conference, 1997. Proceedings., IEEE , vol.3, no., pp.583-631 vol.3, 1-8 Feb 1997 doi: 10.1109/AERO.1997.574914 URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:28979
Deposited By: Tony Diaz
Deposited On:26 Jan 2012 23:12
Last Modified:09 Nov 2021 17:02

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