乐甫波液相传感器的理论和实验分析
文献类型：学位论文
| 作者 | 陈烨 |
| 学位类别 | 博士 |
| 答辩日期 | 2008-05-30 |
| 授予单位 | 中国科学院声学研究所 |
| 授予地点 | 声学研究所 |
| 关键词 | 乐甫波传感器 层状结构 灵敏度 微流封装 |
| 其他题名 | Theoretical and Experimental Analysis of Love Wave Liquid Sensors |
| 学位专业 | 信号与信息处理 |
| 中文摘要 | 生物传感器技术自二十世纪八十年代以来，在全球范围内取得了飞速发展。生物传感器利用特定的生物或化学固定技术，将生物识别元件固定在换能器上，通过声、光、或电信号来检测待测物的量。 乐甫波传感器是一种新型的压电声表面波型传感器。乐甫波是在压电基片表面沉积的薄层声波导中传播的水平剪切波。一方面，由于乐甫波被声波导束缚在表面传播，所以乐甫波器件对表面干扰及质量负载相当敏感；另一方面，由于乐甫波只有平行于基片表面的剪切位移，所以不与液体耦合，传播损耗小，乐甫波器件适合于液相检测。另外，与常规传感器比较，乐甫波传感器还具有高灵敏度（mg-pg级）、检测快速、可原位表征、工艺简单、体积小、价格低、操作简单、可阵列化，低噪声等优点。 本文从理论与实验两个方面研究了乐甫波传感器。 理论上：本文首先研究了具有单层和双层声波导结构的乐甫波传感器。基于声波的波动方程和边界条件，推导出乐甫波频散方程，得到了液相条件下乐甫波的传播特性；然后，对于多层声波导结构的乐甫波传感器，为了避免求解大量声波方程和边界条件，本文基于声电类比原理，建立了多层声波导乐甫波传感器的传输线模型，用以分析多层声波导结构中的乐甫波传播特性；最后，根据上述求解出的传播特性，结合微扰理论得到乐甫波传感器的质量灵敏度，并且给出了质量灵敏度和声波导层材料及厚度的关系。从而为乐甫波传感器的设计提供了理论依据。 实验上：根据理论分析结果，设计并制作了乐甫波传感器件。波导层采用了声速低、声吸收较弱的SU-8聚合膜。以频响曲线和相位作为测量参数，测试了空载时不同声波导厚度的乐甫波器件，得到了乐甫波相速度和损耗与声波导厚度的关系。实验结果和理论结果基本符合。为了保护叉指换能器在测量时不受液体的影响，实验采用PDMS微流芯片对乐甫波器件进行封装，并将封装后的器件用于液相测量，实验中PDMS微流芯片有效地保护了叉指换能器。本文的工作为下一步研制适配子乐甫波生物传感器提供了理论依据和实验基础。 |
| 英文摘要 | Biosensor technology has made rapid development on a global scale since the 1980s. Biosensors are defined as analytical devices incorporating a biological material, a biologically derived material or a biomimic intimately associated with or integrated within a physicochemical transducer or transducing microsystem, which may be optical, electrochemical, mometric, piezoelectric, magnetic or micromechanical. Love wave sensor is a new type of piezoelectric surface acoustic wave sensors. Love waves, which are SH-polarized guided waves, propagate in a layered structure consisting of a piezoelectric substrate and a layer on top of it. On the one hand, because of the waveguiding effect, Love wave devices are very sensitive to surface perturbations and mass loading. On the other hand, since Love waves are SH-polarized and do not have elastic coupling loss in liquids, the propagation loss is low and .Love wave sensors are well suited for sensing applications in liquid. Compared with conventional sensors, Love wave sensors hold the following strengths: high sensitivity (mg-pg level), rapid response, in situ characterization, simple technology, small size, cost reduction, east of use, regular arrays, low loss etc. This paper investigates Love wave sensors from theoretical and experimental aspects. In theory, firstly, the paper investigates love waves behavior in a single-waveguide and double-waveguide structure respectively. The general dispersion equation and propagation characteristics in liquid phase are derived by solving elastic field equations with continuity boundary condition. Then, for multilayer structure, to avoid solving a number of elastic field equations with continuity boundary condition, an equivalent transmission line model is established on base of the analogy between acoustic and electrical waves to determine the propagation characteristics. Finally, combining with the perturbation theory, the relationship between the mass sensitivity and waveguiding layer material, thickness is presented according to the propagation characteristics. The analysis provides a theoretical foundation for the design of the Love wave sensor. In experiment, the Love wave devices are designed and fabricated on the base of theoretical analysis above. The Love wave guiding material is SU-8 polymer, which has a low shear velocity and low acoustic absorption. The frequency response and phase are adopted as measurement parameters. The Love wave devices with different waveguiding layer thicknesses are tested in the air to gain the relationship between phase velocity, insertion loss and layer thickness. The experimental results are almost equal to the theoretical evaluations. To shield the IDTs from liquids, in this thesis, PDMS microfluidic cell is fabricated to package the Love wave devices. The packaged devices are monitored in liquid condition. In the experiment, the PDMS micro-fluidic cell can prevent the presence of liquids on IDTs effectively. This work provides theoretical and experimental foundation for the future research on aptamer Love wave biosensors. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 67 |
| 源URL | [http://159.226.59.140/handle/311008/416]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 陈烨. 乐甫波液相传感器的理论和实验分析[D]. 声学研究所. 中国科学院声学研究所. 2008. |
入库方式： OAI收割
来源：声学研究所
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