涂覆聚合物膜的Love波传播特性

Propagation Properties of Love Waves in Polymer-Coated Devices

该文计算了涂覆聚合物膜的Love波传感器波速和波导层相对膜厚的关系,并进行了实验验证。Love波器件以ST-90°X石英晶体为基片,在基片表面镀一层不同膜厚的聚乙烯醇(PVA)膜作为波导层兼吸湿层。采用网络分析仪测量了相对湿度35%左右器件的工作频率和插入损耗分别随膜厚的变化,算出Love波波速和PVA相对膜厚的关系,当PVA膜厚度从0增大到波长的5%时,Love波速度由约4 992m/s降低到4 840m/s,和理论计算结果一致。

In this paper,the relationship between Love wave velocity and the polymer film thickness was studied by combination of test and numerical calculation.The Love wave device consists of two interdigital transducers（IDTs）,an ST-90°Xquartz substrate,and a polyvinyl alcohol（PVA）layer.A network analyzer was used to measure the operation frequency and insertion loss of the sensor along with the change of film thickness at the relative humidity of 35%.Based on the experimental data,the relationship between Love wave velocity and the polymer film thickness was calculated and the propagation characteristic of Love wave was verified.When PVS film thickness was increased from 0to 5% of the wavelength,the Love wave velocity decreased from ～4 992m/s to 4 840m/s,which is consistent with the calculated results.