A gas sensor array using carbon nanotubes and microfabrication technology

A nanosensor technology has been developed using single-walled carbon nanotubes (SWNTs) combined with silicon-based microfabrication processes. A sensor array containing twelve interdigitated electrode (IDE) pairs with different gap sizes has been designed. The IDE fingers were fabricated using photolithography and thin-film metallization techniques. SWNTs were grown directly on the IDEs for trace amounts of gas detection. This sensor array has been exposed to nitrogen dioxide at various concentrations from 10 ppm to 400 ppb, and ammonia from 50 to 5 ppm. The results show a very reproducible sensor performance from one sensor to the other in the array. (c) 2005 The Electrochemical Society.