A simple and accurate model for Love wave based sensors: Dispersion equation and mass sensitivity
A simple and accurate model for Love wave based sensors: Dispersion equation and mass sensitivity
复制标题
基于乐夫波的传感器的简单而准确的模型：色散方程和质量灵敏度
DOI：
10.1063/1.4886773
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发表时间：
2014-07-01
期刊：
影响因子：
1.6
通讯作者：
Liu, Jiansheng
中科院分区：
文献类型：
--
作者：
Liu, Jiansheng
色散方程是分析声波在层状结构中传播特性的重要工具。对于乐甫波（LW）传感器，考虑各向同性基片的色散方程过于粗糙，难以得到精确解;考虑压电基片的全色散方程过于复杂，难以得到简单实用的表达式，难以优化LW传感器。在这项工作中，色散方程被引入到具有各向异性考虑的衬底和各向同性的引导层的层状结构中的Love波，质量灵敏度的直观表达式也推导出基于色散方程。新的方程是在简单的形式类似于以前报道的简化模型与各向同性基板。通过引入Maxwell-Weichert模型，这些方程也适用于含有粘弹性导向层的LW器件，由复质量灵敏度的真实的部分和虚部分分别得到质量速度灵敏度和质量传播损耗灵敏度。以ST-90度X石英结构上弹性SiO2层中的Love波为例，比较了不同色散方程和相应的质量灵敏度计算得到的速度和归一化灵敏度。数值结果表明，该方法的计算结果与压电基片法的计算结果非常接近。另一个数值计算的情况下，LW传感器与粘弹性引导层进行。如果层的粘性不太大，对速度和质量速度灵敏度的真实的部分影响相对较小;传播损耗和质量损耗灵敏度与引导层的粘性成正比。(C)2014年作者。
Dispersion equation is an important tool for analyzing propagation properties of acoustic waves in layered structures. For Love wave (LW) sensors, the dispersion equation with an isotropic-considered substrate is too rough to get accurate solutions; the full dispersion equation with a piezoelectric-considered substrate is too complicated to get simple and practical expressions for optimizing LW-based sensors. In this work, a dispersion equation is introduced for Love waves in a layered structure with an anisotropic-considered substrate and an isotropic guiding layer; an intuitive expression for mass sensitivity is also derived based on the dispersion equation. The new equations are in simple forms similar to the previously reported simplified model with an isotropic substrate. By introducing the Maxwell-Weichert model, these equations are also applicable to the LW device incorporating a viscoelastic guiding layer; the mass velocity sensitivity and the mass propagation loss sensitivity are obtained from the real part and the imaginary part of the complex mass sensitivity, respectively. With Love waves in an elastic SiO2 layer on an ST-90 degrees X quartz structure, for example, comparisons are carried out between the velocities and normalized sensitivities calculated by using different dispersion equations and corresponding mass sensitivities. Numerical results of the method presented in this work are very close to those of the method with a piezoelectric-considered substrate. Another numerical calculation is carried out for the case of a LW sensor with a viscoelastic guiding layer. If the viscosity of the layer is not too big, the effect on the real part of the velocity and the mass velocity sensitivity is relatively small; the propagation loss and the mass loss sensitivity are proportional to the viscosity of the guiding layer. (C) 2014 Author(s).