Method for QCM Resonator Device Equivalent Circuit Parameter Extraction and Electrode Quality Assessment.

Dong Liu,Qiao Chen,Ziqiao Tang,Xiaoxiong Wang,Yan Yan,Haoran Li,Xiaoting Xiao

doi:10.3390/mi12091086

Abstract

Quartz crystal microbalance (QCM) resonators are used in a wide range of sensors. Current QCM resonators achieve a simultaneous measurement of multiple physical quantities by analyzing lumped-element equivalent parameters, which are obtained via the introduction of external devices. This introduction of external devices will probably increase measurement error. To realize the measurement of multiple physical quantities while eliminating the measurement error caused by external devices, this paper proposes a measurement method for the lumped-element equivalent parameters of QCM resonators without the need for extra external devices. Accordingly, a numerical method for solving nonlinear equations with fewer data points required and a higher accuracy was adopted. A standard crystal resonator parameter extraction experiment is described. The extracted parameters were consistent with the nominal parameters, which confirms the accuracy of this method. Furthermore, six QCM resonator device samples with different electrode diameters and materials were produced and used in the parameter measurement experiment. The linear relationship between the electrode material conductivity and motional resistance R1 is discussed. The ability of this method to characterize the electrode material and to detect the rust status of the electrode is also demonstrated. These abilities support the potential utility of the proposed method for an electrode quality assessment of piezoelectric devices.

Highlights

Quartz crystal microbalances (QCM), as microelectromechanical devices, have been widely used in sensing applications, including humidity [1,2,3,4], liquid [5], and gas sensors [6]
This paper presents a method to measure the equivalent parameters based on the phase–frequency curve of insertion loss (S21) of the resonator device
The experimental results are divided into three parts: (1) the measurement of the standard resonator device parameters, (2) the equivalent parameter measurement of the QCM resonator devices with different electrode diameters, and (3) the equivalent parameter measurement of the QCM resonator devices with different electrode materials

Summary

Introduction

Quartz crystal microbalances (QCM), as microelectromechanical devices, have been widely used in sensing applications, including humidity [1,2,3,4], liquid [5], and gas sensors [6]. Biosensors are primarily used in a liquid environment, and QCM loading has an inhomogeneous structure [10]. Under these conditions, QCM has an effect on the mass [11]. On the viscosity [12] This phenomenon is manifested in the complexity behind the frequency shift interpretation when QCM is used in liquid applications [11].

Methods

Results

Conclusion