声表面波痕量硝基芳香爆炸物传感器敏感机理与性能优化研究

The terrorist bombing which becomes increasingly rampant is the greatest menace to the global people at present. How to detect the explosive rapidly, accurately, instantly and efficiently is the subject which both the international anti-terrorism and the field of public safety pay high attention to. SAW sensors measure the changes of the phase velocity caused by the interaction between the detected gas and the sensitive film to accomplish the gas concentration detecting. As the new means for detecting trace explosive, they have many advantages, such as high sensitivity and integration, quick response, low cost and on-site detection, etc. Currently the native and foreign research on solving the key technical problems about the SAW explosive sensors is strikingly absent from the physical insight. In this project, starting with the optimization of the device configuration, the response mechanisms, function structure and performance optimization of the SAW explosive gas sensors are investigated by the COM theory and FEM method in order to lower the insertion loss and increase the sensitivity, resolution and frequency stability. After solving the basic theoretical issues, the SAW explosive gas sensors with high frequency, high Q value, single resonant mode and compact structure are designed, which can achieve the real-time detection for the trace explosive nitroaromatics. The research results provide a new means for anti-terrorism and explosion proof and have great significance for protecting the country and the life and property safety.

当今日益猖獗的爆炸袭击恐怖活动，是世界人类面临的最大威胁。如何快速、准确、实时、高效地检测爆炸物是国际反恐和公共安全领域高度关注的课题。声表面波传感器通过测量被测气体与敏感膜相互作用所引起的SAW相速度变化完成气体浓度检测，其作为新型爆炸物痕量检测手段具有灵敏度高、集成度高、响应快、成本低、适于现场检测等优点。目前国内外从物理层面上解决SAW爆炸物传感器的关键技术问题明显不足。本项目从优化器件结构入手，以降低器件插入损耗、提高灵敏度、分辨率和频率稳定性为目的，采用COM理论和有限元手段，对SAW爆炸物传感器响应机理、功能结构及性能优化进行研究，解决关键科学问题，设计出高频、高Q值、单一谐振模式、结构紧凑的SAW爆炸物传感器，实现痕量硝基芳香爆炸物现场实时检测。本项目研究成果为反恐防爆工作提供了新手段，对于保护国家和生命财产安全具有重大意义。

当今日益猖獗的爆炸袭击恐怖活动，是世界人类面临的最大威胁。如何快速、准确、实时、高效地检测爆炸物是国际反恐和公共安全领域高度关注的课题。SAW传感器通过测量被测气体与敏感膜相互作用所引起的SAW相速度变化完成气体浓度检测，其作为新型爆炸物痕量检测手段具有灵敏度高、集成度高、响应快、成本低、适于现场检测等优点。目前国内外从物理层面上解决SAW爆炸物传感器的关键技术问题明显不足。本项目从优化器件结构入手，以降低器件插入损耗和提高灵敏度为目的，解决关键科学问题，主要研究内容包括：（1）爆炸物气体响应的动力学过程研究；（2）SAW爆炸物气体传感器响应机理研究；（3）SAW爆炸物气体传感器设计与仿真。项目采用线性溶剂化能方程理论模型量化敏感膜和爆炸物气体间的吸附作用，选择了具有最大吸收强度的PDMS作为爆炸物敏感膜；利用微扰理论获得了聚合物粘弹性敏感膜在不同力学状态下SAW损耗和速度变化量变化趋势，得出当PDMS处于玻璃-橡胶态、初始膜厚 时足以检测500ppb浓度TNT气体；设计了悬浮电极单向换能器（FEUDT）结构SAW气体传感器，利用有限元方法验证了FEUDT结构的单向传播性，提取了COM参数：｜κ11Λ｜=12.57，｜κ12Λ｜=0.02，｜ζ｜2Λ/ωC=0.014和∠(ζ2/κ12)=68.41，发现当a/p=0.92和h/p=0.015时，反射和换能中心位相差角为44.8°，非常接近理想值45°；运用坡印廷矢量研究了FEUDT结构传感器能量传输特性，发现衬底中几乎没有以体波形式损失的声能量，而且FEUDT周期越多获得的方向性更强；对比了基于传统IDT和FEUDT的延迟线型和谐振型TNT气体传感器灵敏度，发现FEUDT型SAW传感器可以有效减小插入损耗，而且FEUDT谐振型传感器灵敏度（94.8Hz/ppb）比延迟线型（46.2Hz/ppb）更大。项目研究成果为反恐防爆工作提供了新手段，对于保护国家和生命财产安全具有重大意义。