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

Mark C. Lonergan, Michael S. Freund, Erik J. Severin, Brett J. Doleman, Robert H. Grubbs, Nathan S Lewis

Research output: Chapter in Book/Report/Conference proceedingConference contribution

7 Citations (Scopus)


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.

Original languageEnglish
Title of host publicationIEEE Aerospace Applications Conference Proceedings
Editors Anon
Number of pages49
Publication statusPublished - 1997
EventProceedings of the 1997 IEEE Aerospace Conference. Part 4 (of 4) - Snowmass Village, CO, USA
Duration: Feb 1 1997Feb 2 1997


OtherProceedings of the 1997 IEEE Aerospace Conference. Part 4 (of 4)
CitySnowmass Village, CO, USA

ASJC Scopus subject areas

  • Engineering(all)

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