Benzene monitoring by micro-machined sensors with SnO₂ layer obtained by using micro-droplet deposition technique

SnO₂ thin layers were deposited by the way of the micro-droplet technique. The sensor substrate consisted of a thin membrane developed on oxidised silicon wafer. The sensing layers were deposited by means of the micro-droplet technique into thin layers of about 100nm. Such devices were tested for benzene detection. The obtained results showed a very high sensitivity for this chemical compound since 500ppb were detected. The results presented in this paper were not focused on the reactional mechanism of benzene detection but rather on the development of a cheap and sensitive sensor using sol–gel and micro-droplet processes. Since these layers were elaborated using solely tin oxide, the as-obtained sensors are not selective but these one are intended to be used by coupling with additional devices such as chromatographic micro-column and micro-pre-concentrators.