Detection of dilute aromatic VOCs using WO 3 thin film sensors equipped with Au interdigitated microelectrode

Abstract

Sensing properties to dilute aromatic VOCs (toluene, xylene, ethylbenzene, and styrene) have been investigated for the WO 3 thin film microsensors equipped with Au interdigitated microelectrode. The sensor response (S=Ra/Rg) was increased with decreasing teeth distance of interdigitated electrode in the range of 2-5 μm. The WO 3 microsensor with 2 μm interdigitated electorde showed the highest sensor response to dilute aromatic VOCs at 500 °C The WO 3 microsensor with 2 μm interdigitated electrode exhibited the sufficient sensor response (S>3) to 0.01 ppm aromatic VOCs, particularly high sensor response (S=6) to 0.01 ppm xylene, at 500 °C with the excellent response-recovery characteristics. This behavior suggests that the WO 3 thin film microsensors equipped with Au interdigitated microelectrode can be used as a high sensitivity aromatic VOC sensor. © 2008 The Institute of Electrical Engineers of Japan.