An investigation of polymer-carbon black composite gas detectors

In this paper, we describe the development of novel chemical gas sensors. These sensors consist of sensitive films and interdigited microelectrodes. The sensitive films are made of insulating polymers mixed with conducting carbon black. Interdigitated microelectrodes made of gold are fabricated on the silicon by VLSI technology and packaged. With the deposition of different polymer films on the interdigitated electrodes, we can make various polymer-carbon black composites chemresistive gas microsensors. When the sensitive films are exposed to organic gases, these films will absorb the gases and swell, that is, the resistance of the films goes to increase. We test two kinds of microsensors exposed in the same concentrations of organic gases. By principle component analysis of responses of microsensors, it is clear that two kinds of the same concentration different gases can be easily discriminated.