Lectura sin contacto de resonadores de cristal de cuarzo para aplicaciones de microbalanzas multicanal

Abstract

A configuration and method for contactless readout of the resonance response of a multichannel quartz crystal microbalance (MQCM) is presented. The configuration uses a crystal with a large common electrode on the front face, and small electrodes on the back face, leading to localized sensing regions. Each back electrode is capacitively coupled to a separated tip electrode, consisting of a small disc and a active guard ring. A model composed of a Butterworth-Van Dyke (BVD) circuit and a coupling capacity in series and expressions showing the influence of the coupling on the measured parameters and frequencies of the resonators are presented. Experimental results show that a mass load added on the front electrode can be consistently detected and measured.