MEMS technology was used to fabricate arrays of sensor for detecting the explosive micro particulate residue found in mine fields. MEMS devices were fabricated by a surface micromachining process provided by MCNC. The sensor consists of a bimorph structure of polysilicon/gold cantilevers. An optical detection system was designed to detect the deflection of the cantilevers. The sensors were heated by either radiation or conduction using an UV lamp and a small heater under the sensor chip respectively. The deflection of the cantilevers with increasing temperature is presented. Experiments have been performed to detect the response of the cantilevers in the presence of an explosive particle. The cantilevers show a response due to the presence due to the presence of nanograms of TNT and RDX in the vicinity of the cantilevers. Currently it is understood that the response shown by the cantilevers is due to the vaporization of the micro particles, which pulls significant heat out of the temperature sensitive beams causing detectable beam motion. The chemical selectivity of the sensor is provided by the unique melting temperatures of TNT and RDX.

Date Published: 2 August 1999
PDF: 7 pages
Proc. SPIE 3710, Detection and Remediation Technologies for Mines and Minelike Targets IV, (2 August 1999); doi: 10.1117/12.357055

Published in SPIE Proceedings Vol. 3710:
Detection and Remediation Technologies for Mines and Minelike Targets IV
Abinash C. Dubey; James F. Harvey; J. Thomas Broach; Regina E. Dugan, Editor(s)