Accession Number:

ADA139636

Title:

CHEMFET (Chemically Sensitive Field-Effect Transistor) Chemical Warfare Agent Detector.

Descriptive Note:

Final rept. 15 Dec 81-15 Jan 83,

Corporate Author:

UTAH UNIV SALT LAKE CITY DEPT OF BIOENGINEERING

Personal Author(s):

Report Date:

1983-12-01

Pagination or Media Count:

17.0

Abstract:

In detector technology, one item whose feasibility as a cockpit chemical warfare agent detector has been demonstrated is the chemically sensitive field-effect transistor CHEMFET. The overall objective of the present effort was to test and evaluate CHEMFET semiconducting polymer gate electrode material and to design, build and optimize a breadboard detector by using selected material. A membrane consisting of a poly vinyl pyrrolidone, poly vinyl alcohol, and copper II bipyridine mix the selected material was cast over coppercopper bipyridyl electrodes for form a cell, the resistance of which was shown to change on exposure to organophosphonates and other vapors. These resistance changes, however, originated at the metal-polymer contact and were not due to change in bulk resistivity. Since this membrane could not then be used as a gas-sensitive layer in a CHEMFET structure as had originally been hoped, the direction of the research was changed. Because of the extreme sensitivity of impedance measurements, made as a function of diisopropyl methylphosphonate DIMP and other organophosphorous vapor concentrations, an effort has been planned and is progressing towards building a dedicated battery-operated low-frequency bridge to measure the impedance of the organophosphonate sensitive resistance cell.

Subject Categories:

  • Chemical, Biological and Radiological Warfare

Distribution Statement:

APPROVED FOR PUBLIC RELEASE