Sun Xiaqing, Fu Quanhong, Fan Yuancheng, Wu Hongjing, Qiu Kepeng, Yang Ruisheng, Cai Weiqi, Zhang Nan, Zhang Fuli
Research & Development Institute in Shenzhen, Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, and Department of Applied Physics, School of Natural and Applied Sciences, Northwestern Polytechnical University, Xi'an, 710072, China.
School of Mechanical Engineering, Northwestern Polytechnical University, Xi'an, 710072, China.
Sci Rep. 2019 Apr 1;9(1):5417. doi: 10.1038/s41598-019-41681-5.
Active control of metamaterial properties is of great significance for designing miniaturized and versatile devices in practical engineering applications. Taking advantage of the highly temperature-dependent permittivity of water, we demonstrate a water-based metamaterial comprising water cubes with thermally tunable Mie resonances. The dynamic tunability of the water-based metamaterial was investigated via numerical simulations and experiments. A water cube exhibits both magnetic and electric response in the frequency range of interest. The magnetic response is primarily magnetic dipole resonance, while the electric response is a superposition of electric dipole resonance and a smooth Fabry-Pérot background. Using temporal coupled-mode theory (TCMT), the role of direct scattering is evaluated and the Mie resonance modes are analyzed. As the temperature of water cube varies from 20 °C to 80 °C, the magnetic and electric resonance frequencies exhibit obvious blue shifts of 0.10 and 0.14 GHz, respectively.
在实际工程应用中，对超材料特性进行主动控制对于设计小型化和多功能器件具有重要意义。利用水的介电常数对温度高度敏感的特性，我们展示了一种由具有热可调米氏共振的水立方组成的水基超材料。通过数值模拟和实验研究了水基超材料的动态可调性。在感兴趣的频率范围内，水立方表现出磁响应和电响应。磁响应主要是磁偶极共振，而电响应是电偶极共振和平滑法布里-珀罗背景的叠加。使用时间耦合模理论（TCMT），评估了直接散射的作用并分析了米氏共振模式。当水立方的温度从20°C变化到80°C时，磁共振频率和电共振频率分别出现明显的蓝移，分别为0.10和0.14 GHz。
