Multi-frequency interrogation of nanostructured gas sensor arrays

In this paper, for the first time two types of highly sensitive nanostructured metal oxides are specifically designed to reveal the physicochemical mechanisms enhanced by multi frequency interrogation. Both types of films employ identical silicon transducers but while the first one is designed for its response kinetics to be limited by gas diffusion, the second one is designed for its response kinetics to be limited by reaction. Indeed, our results employing a multi-frequency approach show that the optimal temperature modulation frequencies needed to selectively detect hydrogen are significantly higher for the second type of sensors.