Visokonivojsko modeliranje in nacrtovanje veckanalnega senzorskega sistema za zaznavanje razlicnih molekul v zraku/High-Level Modeling and Design of a Multichannel Sensor System for Vapor Trace Detection of Different Molecules in the Air

• Published in: Elektrotehniski Vestnik Vol. 82; no. 5; p. 253
• Main Author: Strle, Drago
• Format: Journal Article
• Language: English; Slovenian
• Published: 01.01.2015
• Subjects: Algorithms; Capacitance; Computer simulation; Design engineering; Digital signal processing; Multichannel; Sensors; Signal processing
• ISSN: 0013-5852; 2232-3236

Design, implementation and high-level modeling and simulation of a multi-channel sensor system for the vapor trace detection of different molecules in the air are presented in the paper. The detection is based on the change of the capacitance when a target molecules adsorb to the surface of a chemically-modified COMB capacitive sensor. An integrated low-noise analog electronic circuit with corresponding digital signal processing algorithms measures a small capacitance change. The detection limit is in the range below 1aF/[radic]Hz which makes it sure that the detection limit is in the range of three molecules of TNT in 1012 molecules of the carrier gas in one second, which ranks the sensitivity among the best in the world. The array of differently modified sensors provides the possibility to improve the selectivity; the low-noise signal processing provides a low detection level while a digital signal processing assures a multichannel processing of the signals in real time. A comparison is made between the simulation and measurement results.