Directly heated quartz crystal microbalance with an integrated dielectric sensor

Cross sensitivity, especially to humidity, is a common problem in the analysis of chemical gas sensor signals. To identify the contributions of two gas components at least two suitable signals are needed. This article presents a new chemical sensor unit which is a combination of a quartz crystal microbalance and a dielectric sensor. Thus it yields information about both the mass and the dielectrice of the same chemical sensitive film. To make this an universal element for gas sensing, a heater and a temperature gauge are also integrated directly on the quartz by thin film technology. This allows the application of temperature modulation techniques to the quartz microbalance principle.