The role of shear modulus and viscosity of thin organic films on the adsorption response of QCM sensors

Abstract

This work reports on the results of numerical calculations of quartz microbalance (QCM) sensors' response under the adsorption of analyte molecules. The influence of share modulus and viscosity has been studied. It was shown that even in the case of sufficiently thin films (hundreds of nanometers), the viscosity effects can significantly affect the sensor response during adsorption. In the case of sufficiently thick layers, the viscosity effects can turn out to radically change the response of QCM to the adsorption of volatile molecules. Thus, utilizing QCM-based sensors in a viscous medium, it is necessary to take into account not only the mass loaded (adsorbed) onto the quartz surface but also the effect of viscosity on sensor response.