Trivedi Shyam, Nemade Harshal B
Center for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
Center for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India; Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
Ultrasonics. 2018 Mar;84:150-161. doi: 10.1016/j.ultras.2017.10.004. Epub 2017 Nov 3.
The paper presents 3D finite element simulation and analysis of Love wave resonator with different guiding layer materials and investigation of the coupled resonance effect with ZnO nanorods on the device surface. Analytical estimation of phase velocity and mass sensitivity of Love wave device with SiO, ZnO, gold, SU-8, and parylene-C as guiding layer materials is performed for comparative analysis. Simulations are carried out to study the variation in electromechanical coupling coefficient, displacement profile and frequency response of the Love wave resonator. SU-8 offers high mass sensitivity of 1044 m/kg while gold layer provides maximum K of 8.6%. In comparison to SiO and ZnO, polymers exhibit sharp rise and fall in K within a narrow range of normalized layer thickness (0.03-0.1). ZnO nanorods of varying height and surface nanorod density are designed over the Love wave resonator with SiO as the waveguiding layer. In the presence of coupled resonance, the nanorods and substrate vibrate in unison causing an increase in average stress and mass sensitivity but leads to decrease in the electromechanical coupling coefficient of the device. Surface nanorod packing density of 25 μm offers high mass sensitivity of 1304 m/kg that is 20 times greater in comparison to the mass sensitivity of a plain Love wave device.
本文介绍了具有不同导向层材料的乐甫波谐振器的三维有限元模拟与分析，以及对器件表面氧化锌纳米棒耦合谐振效应的研究。对以二氧化硅、氧化锌、金、SU-8和聚对二甲苯-C作为导向层材料的乐甫波器件的相速度和质量灵敏度进行了解析估计，以进行对比分析。开展模拟以研究乐甫波谐振器的机电耦合系数、位移分布和频率响应的变化。SU-8提供了1044 m/kg的高质量灵敏度，而金层提供了8.6%的最大机电耦合系数。与二氧化硅和氧化锌相比，聚合物在归一化层厚度的窄范围内（0.03 - 0.1），机电耦合系数呈现急剧上升和下降。在以二氧化硅作为波导层的乐甫波谐振器上设计了不同高度和表面纳米棒密度的氧化锌纳米棒。在耦合谐振存在的情况下，纳米棒和衬底同步振动，导致平均应力和质量灵敏度增加，但器件的机电耦合系数降低。表面纳米棒堆积密度为25μm时提供了1304 m/kg的高质量灵敏度，这比普通乐甫波器件的质量灵敏度高20倍。
