Transient quartz crystal microbalance behaviors compared

A new method for studying the properties of the loaded quartz crystal microbalance (QCM) called the "dissipation technique'' is generating a great deal of interest. The QCM is excited near its resonant frequency and then short-circuited, the decay time of the current being a measure of the dissipation. The existing steady-state methods to model the QCM are not applicable. The inventors of the technology from the Chalmers Institute of Technology obtained useful transient solutions using a mechanical model. We show that transient solutions to the QCM problem can also be obtained using the electromechanical model, which had earlier been used for the steady-state studies. Using this model, it is possible to find two separate methods of solution, each of which can distinguish between short-circuit and open-circuit transient behaviors. We compare these solutions with one another and also with the Chalmers results. We also show experimental data comparing the solutions for the case of water-glycerol mixtures of various concentrations. (C) 2001 The Electrochemical Society.