A Flexible Wireless Sensor based on SRR for Nondestructive Detection of Metal Crack

To meet the demand for wireless, passive, and real-time detection of surface cracks in infrastructures such as bridges and pipelines, this paper designs a crack sensor based on the Split Ring Resonator (SRR) structure. Firstly, the key parameters of the sensor are optimized using HFSS software to obtain a design scheme with high Q-factor. The electric field distribution characteristics of the sensor are analyzed, and the response of its resonant frequency is verified by simulating the variation of crack width, thus confirming the feasibility of the sensor for crack detection. Then, a 0.1 mm-thick flexible PI film is selected as the substrate, and the sensor fabrication is completed via the gold plating process. Finally, a test platform is built to verify the sensor performance. The test results show that the sensor can achieve non-contact crack width detection with a sensitivity of 60 MHz\/mm. This sensor with the advantages of flexibility, miniaturization and networkability, exhibits broad application potential in surface crack detection for bridges, pipelines and other related fields.

为满足桥梁、管道等基础设施表面裂缝无线、无源且实时检测的需求，本文设计了一款基于开口环谐振器（Split Ring Resonator, SRR）结构的裂缝传感器。首先，本文采用HFSS软件对该传感器的关键参数进行优化，得到了具备高品质因数的设计方案。随后，本文分析了该传感器的电场分布特性，并通过模拟裂缝宽度变化验证了其谐振频率响应特性，由此证实了该传感器用于裂缝检测的可行性。接着，本文选用厚度为0.1mm的柔性聚酰亚胺（Polyimide, PI）薄膜作为基板，并通过镀金工艺完成了传感器的制备。最后，搭建测试平台以验证传感器性能。测试结果表明，该传感器可实现非接触式裂缝宽度检测，灵敏度可达60MHz/mm。这款兼具柔性、小型化与网络化优势的传感器，在桥梁、管道等领域的表面裂缝检测中展现出广阔的应用前景。