为了制作高灵敏度Love波传感器,分析了Love波在ST-石英和二氧化硅薄膜分层结构中的传播特性,并对该分层结构进行了相关的理论推导和计算。首先,从声学动力学方程出发,分析求解了该分层结构的波动方程,得到了在该分层结构的色散关系及位移表达式。基于得到的解析表达式分析了波结构,绘制了特性曲线,得到了Love波在该结构中的传播特性。最后,应用MEMS工艺制作了由ST-石英为基底、二氧化硅为波导层的Love波传感器,并通过电化学微电铸的方法进行了实验验证,且对理论灵敏度与实验灵敏度之间不一致的原因进行了分析。测试数据显示,该传感器的质量灵敏度为100cm2/g,最低检出限为3.65ng,结果证明了该Love波传感器基本满足高灵敏度生化检测的要求。
In order to obtain a high sensitive Love wave mass sensor,the Love wave propagation characteristics in a layered structure consisting of a ST-quartz and a silica were investigated theoretically and experimentally on the basis of acoustic dynamics,the wave equation for the layered structure was analyzed and its displacement and the dispersion curves were obtained by calculation.According to the computing results,a Love wave sensor with a SiO2 waveguide layer was designed and fabricated on a ST-quartz substrate by MEMS processes and its sensitivity was tested by electro-deposition experiment.The results indicate that the mass sensitivity of the device is 100 cm2/g and the detection limit is 3.65 ng,which meets the demand of biochemical detection for higher sensitivity basically.