Gas microsensors based on polymer-carbon black composites

We describe novel chemical gas sensor arrays based on polymer-carbon black composites. Four different polymers, poly(4-vinyl phenol), poly(ethylene oxide), polycapraclactone (PCL) and polyethylene-co-vinylacetate (PEVA), are employed as the sensing materials which are fixed on the array of interdigitated microelectrode pairs. The resistance changes of the sensors to four organic gases (acetone, ethanol, toluene and methanol) at 500 ppm concentration have been examined. By principal component analysis of the responses of the microsensors, it is clear that four kinds of the same concentration of the different gases can easily be discriminated. Furthermore, when some gases, such as ethanol and acetone, are detected using the sensing membranes of poly(4-vinyl phenol) and poly(ethylene oxide), the relationship between the resistance changes and gas concentration in the range from 300 ppm to 1500 ppm can be approximated to a straight line.