Development of gas sensors by microwave transduction with phthalocyanine film

This work presents a new transduction mode for gas sensing using a passive microwave circuit at room temperature. The design of the sensor includes a microstrip line where is deposited a thin molecular layer of cobalt phthalocyanine (CoPc). The material is sensitive to ammonia and toluene. Submitted to an electromagnetic incident wave in the microwave range, the sensor response is a reflected wave. In the presence of ammonia, the reflected wave is specific to the species concentration. The sensor response is the reflected wave over the incident wave ratio at each frequency traduced by the reflected coefficient. The study deals with the influence of molecular sensitive materials on the sensor response in the presence of ammonia (or toluene) in an argon flow. (C) 2012 Elsevier Ltd .... Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o.