Prediction of quartz crystal microbalance gas sensor responses using a computational chemistry method

Abstract

The characteristics of quartz crystal microbalance (QCM) gas sensors depend on the kinds of sensing films coated on their electrodes. Although it is essential, in an odor sensing system, to know the characteristics of various sensing films, they have not been characterized well enough to predict the sensor responses without any experiments. Hence, we tried to predict sensor responses using a computational chemistry method. The prediction of the sensor responses enables us to easily design the combination of sensors in an odor sensing system. In this study, we calculated the amounts of gas molecules such as alcohols, aromatics, ketones, esters, alkanes and perfumes sorbed into typical sensing films, and compared them with experimental results. Consequently, it was found that the tendency of QCM sensor responses to vapors over a wide range of odor intensity could almost be predicted by a computational chemistry method if the chemical structures of the film and gas molecules are known. Moreover, the effects of sensing film polarities appeared significant in both simulations and experiments.