基于电磁超表面的主动调控及高性能太赫兹传感器设计与机理研究

Due to the characteristics of spectral resolution, non-destructive and label-free features, terahertz (THz) sensing technology based on electromagnetic metasurfaces has very important application prospects in the fields of material identification, qualitative/quantitative analysis and biomedical detection, becoming an interesting research topic. However, most of the THz metasurface sensors are currently constructed of metal materials, and there are two major problems of ohmic loss and difficulty in active modulation, which greatly limits the performance of the sensor. Here, the work to be carried out in this project mainly includes: (1) Design and study the THz metasurface structure with toroidal dipole resonance response dominated to achieve ultra-high quality factor Q; Combining the toroidal metasurface structure with the microfluidic channel, a THz sensor with ultra-high sensing performance FoM is designed to realize sensing detection of gas and liquid; (2) Using low-loss dielectric materials instead of metals, designing and constructing THz metasurface sensors to solve ohmic losses that metal materials cannot avoid, and improving sensing performance; (3) Designing metasurface sensors by using graphene and flexible materials like PDMS instead of metal and hard substrate such as quartz and silicon; The graphene Fermi level and the metasurface structure shape are changed by means of external bias voltage and mechanical force, realizing the active modulation of the sensor.

由于具有特征光谱分辨能力、非破坏和无标记等特点，基于超表面的太赫兹传感技术在物质识别、定性/定量分析以及生物医学检测等领域具有非常重要的应用前景，成为国内外研究热点。但是，目前大部分太赫兹超表面传感器都由金属设计构造，存在欧姆损耗和难以主动调控两大问题，致使传感器性能受到很大限制。针对上述问题，本项目拟开展的工作主要包括：（1）设计研究环形偶极子共振响应占主导的太赫兹超表面结构，实现超高品质因子Q；将环形超表面结构与微流体通道结合，设计具有超高传感性能FoM的太赫兹传感器，实现对气体、液体的传感检测；（2）利用低损耗介质材料替代金属，设计构造太赫兹超表面传感器，解决金属材料无法避免的欧姆损耗问题，提高传感性能；（3）利用石墨烯、柔性基底材料如PDMS替代金属及石英、硅等硬质基底，设计超表面传感器；通过外加偏压、机械力等方式改变石墨烯费米能级及超表面结构形状，实现传感器的主动调控功能。

由于具有特征指纹谱、非破坏以及无标记等特点，太赫兹超表面传感在物质识别、定量检测领域具有重要应用前景。项目通过研究高Q值超表面传感器，增强太赫兹与物质相互作用，实现高效、多功能检测识别。主要研究内容有：1）研究设计集成微通道的TD共振超表面传感器，其Q值和FoM值达到1103和244，并实现对极性、非极性液体检测识别；2）提出设计TD共振介质超表面，其Q值和FoM值达到3189、515，传感性能大大优于同类型金属超表面传感器；3）设计TD-BIC共振多功能高效超表面传感器，实现高Q、高传感灵敏度S以及高FoM，突破传统频移传感厚度检测限制，实现对纳米薄膜高效检测；4）研究集成石墨烯、相变材料的法诺共振超表面，实现对共振振幅、频率的动态调控及主动传感；5）研究葡萄糖无水、一水混合物，防腐剂混合物太赫兹光谱，结合机器学习和波谱解析方法，实现对混合物快速识别和定量检测。项目发表SCI论文9篇，被引用150余次，申请专利4项（授权2项），参加学术会议3次。项目执行期内，项目负责人入选陕西省青年科技新星、中国科学院西部青年学者A类。