Quartz crystal resonator measurements can be used for polymer materialcharacterization. The non-gravimetric regime of these resonators isexploited: the electrical response of polymer-coated quartz resonatorsdepends on the polymer shear modulus. Previously reported methods employ anelectrical admittance analysis together with difficult and time-consumingdata fitting procedures to calculate the film shear modulus. Thiscontribution presents a fast and accurate three-step method for thecalculation of complex shear moduli of polymer films from quartz crystalresonator measurements. In the first step, the acoustic load impedance iscalculated from the electrical admittance of the quartz crystal. The keypoint of this method is the application of a family of approximations forthe calculation of the shear modulus from the acoustic load impedance in thesecond step. In the third step, the best approximation is improved furtherin an iterative procedure.
© 1999, by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.