Abstract-Frequency-switchable VO-based coding metasurfaces at the terahertz band

Jiahui Li, Yating Zhang, Jining Li, Jie Li, Yue Yang, Jin Huang, Chengqi Ma, Zhenzhen Ma, Zhang Zhang, Lanju Liang, Jianquan Yao



https://www.sciencedirect.com/science/article/abs/pii/S0030401819309204

In this paper, a frequency-switchable terahertz coding metasurface is demonstrated based on the phase transition of vanadium dioxide. Temperature excitation can initiate the insulator–metal transition of vanadium dioxide, thereby changing the resonant frequency of the metal-vanadium dioxide composite unit structure, then changing the operating frequency of the entire coding metasurfaces. We first design a 1-bit coding metasurface whose working frequency can be switched between 1 THz and 1.4 THz, with a switching bandwidth of 0.4 THz. Further more, a 2-bit coding metaurface is designed, whose working frequency can be switched between 1 THz and 1.5 THz with a switching bandwidth of 0.5 THz. This work provides a new design idea for the terahertz active coding metasurfaces which opens up a broad path for coding metasurface applications such as wireless terahertz communications.

Abstract-Sensitive detection of cancer cell apoptosis based on the non-bianisotropic metamaterials biosensors in terahertz frequency

Zhang Zhang, Hongwei Ding, Xin Yan, Lanju Liang, Dequan Wei, Meng Wang, Qili Yang, and Jianquan Yao

https://www.osapublishing.org/ome/abstract.cfm?uri=ome-8-3-659&origin=search

The apoptosis of cancer cells was experimentally measured by terahertz (THz) biosensors based on the metamaterials (MMs). The non-bianisotropic resonance with an electric field of up to 106 V/m was exhibited at 0.85 THz, where the magnetic dipoles were cancelled in the unit cell. The simulate results show the dependence of the frequency shift on the occupying ratio and refractive index of analytes. The theoretical sensitivity was calculated to 182 GHz/RIU. The experimental results imply that the resonant frequency would red shift with the increase of the concentration of cancer cells. Furthermore, the apoptosis of cancer cells HSC3 under the effect of drug concentration from 1 to 15 μM and drug action time from 24 to 72 hours were also studied by the biosensors, respectively. It shows that the trend agrees with the results measured by the biological CCK-8 kits method. Our proposed MMs-based biosensors may supply a novel viewpoint on cell apoptosis from a physical perspective and be a valuable complementary reference for biological study.

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