冷凝吸附式声表面波气体传感器响应机理及应用研究

The SAW gas sensors based on the condensate-adsorption effect with the characteristics of wide span, high speed, great ability of anti-disturbance， high sensitivity, low-cost, are more effective in real-time monitoring, and exhibit the high prospect and significant academic value in the environment pollution and public security, and the research on them has become another hot spot in sensor technology. However, current Response-Mechanism patterns of the SAW sensors based on the condensate-adsorption effect are not quite accurate. Furthermore, no theoretical pattern of and research on the key condensate-adsorption efficiency has been established and conducted. This research aims to work out the sensors based on the condensate-adsorption effect and promote their application by breaking through the key technologies-analyzing the basic theoretical pattern，researching on the relationship between the condensate-adsorption effect and threshold detection limit, and prioritizing the physical structure of the said sensors. The main contents of this proposal include: (1)the investigating of the absorption characteristics of the gas on the ST-X quartz chip and on the interdigital transducers (IDTs); (2) the analyses on the response mechanism and threshold detection limit of the sensors based on the condensate-adsorption effect; (3) the fabrication of the SAW resonator with low insertion loss and single-mode control, and the development of the SAW oscillator with excellent frequency stability, in which the fabricated SAW resonator was used as feedback; (4) the establishment of experimental platform and the confirmation by experiments. The proposal is of great significance in promoting the real application of such kind of sensors.

基于冷凝吸附模式的声表面波气体传感器因具有检测范围宽、速度快、抗干扰能力强、灵敏度高、成本低等特点，使其在现场实时检测领域极具优势，在环境污染、公共安全等的质量监测方面显示出极大应用前景与重大学术价值，成为传感器技术当前研究的又一热点。但目前针对冷凝吸附式气体传感器的响应机理分析模型不够准确，而且对其中关键的冷凝吸附效率问题几乎没有相应的理论模型及研究。本项目拟通过对冷凝吸附式SAW传感器的基础理论模型的分析，冷凝吸附效率与检测下限关系的研究、物理结构的优化制备等，促进其真正走向实用化。主要研究内容为：（1）气体在ST-X石英基片表面及金属叉指电极上的吸附特性研究；（2）冷凝吸附式SAW传感器的响应机理及检测下限研究；（3）低损耗与单模式控制的SAW谐振器及以此为频控原件的振荡器的研制；（4）实验平台的搭建及实验验证。本项目的开展对冷凝吸附式声表面波气体传感器的真正实用化具有重要的意义。

目前针对冷凝吸附式气体传感器的响应机理分析模型不够准确，而且对其中关键的冷凝吸附效率问题几乎没有相应的理论模型及研究。本项目通过对冷凝吸附式SAW传感器基础理论模型的建立，响应机理的研究，冷凝吸附效率与检测下限关系的研究、低损耗与单模式控制的SAW谐振器的优化制备，并搭建实验平台对理论研究结果进行了实验验证等，取得以下成果1)确立了吸附效率与基片表面性状、SAW叉指电极材料、冷凝温度梯度的关系，设计出了对易挥发性气体吸附效率有明显提高的声表面波器件表面加工工艺方法；2)建立了基于冷凝吸附模式SAW气体传感器响应机理及质量检测下限的理论分析模型；3)完成了冷凝吸附式SAW气体传感器的气体实验，并建立了相应的测试评价方法；4)在本项目的研究工作中，目前已申请专利2项，其中发明专利一项，已发表标记论文9篇，录用待发表的标记论文2篇。通过本项目的开展，为冷凝吸附式声表面波气体传感器的真正实用化奠定了理论基础，同时对于丰富质量检测类SAW传感器响应机理分析、高性能检测器结构的优化分析等具有重要的意义。