Date of Award

12-1990

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering

Department

Department of Electrical and Computer Engineering

First Advisor

Edward Kolesar, PhD

Abstract

This study used integrated circuit microsensors to detect organophosphorus compounds. Chemically-sensitive thin films, copper phthalocyanine, DFPase, succinyl chloride, succinylcholine chloride, 2- naphthol(B), and L-histidine dihydrochloride,were deposited on interdigitated gate electrode (IGE) structures, with an average thickness of 2000A. Thin film electrical performance characteristics were measured for several parameters, including: DC resistance, AC impedance, time-domain, and spectral responses from 10 Hz to 1 MHz. Each microsensor contained nine IGEs; each IGE possessed an in situ field-effect transistor amplifier. After purging each sensor with filtered air, it was exposed to one or two of the following gases: diisopropyl fluorophosphate (DFP), diisopropyl methylphosphonate, and dimethyl methylphosphonate at concentrations spanning 100 ppb to 10 ppm (at 90% relative humidity and 23° C). Testing was conducted with microsensors heated to 30, 50, and 70 degrees C. All six candidate films, demonstrated various degrees of sensitivity to the challenge gases at 30 degrees C. DFPase was especially sensitive to the challenge gases at 100 ppb. Only copper phthalocyanine and L- histidine dihydrochloride demonstrated sensitivity above 30 degrees C. In particular 2-naphthol(B) showed complete reversibility and succinyl chloride demonstrated partial reversibility at 30° C. Copper phthalocyanine was reversible only at 70° C. Succinylcholine chloride demonstrated a unique band-reject filter response to the presence of DFP in any challenge gas sample.

AFIT Designator

AFIT-GE-ENG-90D-07

DTIC Accession Number

ADA230161

Comments

The author's Vita page is omitted

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