Vibration Characteristics Analysis And Numerical Simulation Of New Polymer Quartz Piezoelectric Sensor

This paper studied the vibration behavior of a new type of polymer quartz piezoelectric sensor. The substraten of new polymer quartz piezoelectric sensor is a type AT cut quartz piezoelectric wafer with piezoelectric effect. There are three thin plates polymer ring-quartz disc-polymer ring by means of evaporation on substrate surface using "vacuum electron beam dispersion (EBD) coating technology". This sensor collects information by adsorption-stripping properties of polymer thin film materials for material under test. It realizes detection function by using the pattern recognition system to simulate human olfactory system with advantages of simple structure, quick detection and low cost. The working principle of new type polymer quartz piezoelectric sensor is based on the Sauerbrey equation of quartz crystal microbalance (QCM). The adsorption properties of the polymer film sensor surface causes the changes of quality of the sensor and leads to changes in its natural frequency. Through the piezoelectric effect of type AT cut quartz piezoelectric crystal, electrical signal is output containing its natural frequency. The main contents of this article include the following sections:(1) Based on analysis of the physical and chemical properties of gas under test and polymer materials, the affinity was studied between different kinds of polymer and the identification of gas under test, and the thin film formula was obtained in view of adsorption-stripping properties of polymer thin film materials for material under test; Through the experimental study, the best preparation technology of different polymer material was obtained by the "vacuum electron beam dispersion (EBD) coating technology" and developed the polymer quartz piezoelectric sensor with specific adsorption properties for materials under test.(2) In view of the theoretical study on the vibration behavior of new polymer quartz piezoelectric sensor, the model of three thin plates ring-disc-ring was established; Based on the Kirchhoff plate theory, the mechanical model of displacement field and electric potential field distribution was studied by assuming the vertical displacement of the neutral surface. The bending moment and shear force of the quartz substrate with piezoelectric effect was listed under the action of force electric coupling and the characteristic equation containing the natural frequency was obtained under the condition of fixed support.(3) The1-100order natural frequency was calculated through assignment on geometry size, the material property of model based on MATLAB software platform. The modal analysis of polymer quartz piezoelectric sensor mechanical model was carried out through ANSYS finite element software and obtained1-100order natural frequency and vibration modes. By comparing the1-100order natural frequency of the theoretical value and the simulation value, it is concluded that the mechanical model based on the theory of Kirchhoff plate conforms to the new type of polymer quartz piezoelectric sensor, and the mechanical model provides a theoretical support for optimizing the design of new type polymer quartz piezoelectric sensor.