A sub-second QCM humidity sensor with low hysteresis base on Nafion thin film

In this paper, we developed a QCM humidity sensor with Nafion thin film coated on its electrode. An impedance-based QCM measurement system proposed in our previous work was used for measurement without oscillators. The experimental results indicate that the obtained QCM sensor has an ultrafast response speed (0.6/0.9 s) and very low hysteresis (1.61% RH). This may be related to the low amount of Nafion on the QCM electrode and the thin enough film generated on it.