Design and verification of a high-Q, high-sensitivity, multi-mode metasurface and measurement of its clothing fabric sensing performance

A multi-mode resonant metasurface based on asymmetry is verified and optimized in the 1.0–16.0 THz range. Two toroidal dipole modes (ETD1 and ETD2) with high Q values and high sensitivity are revealed by this asymmetry metasurface, which demonstrates resonant characteristics different from traditional metamaterials/metasurfaces. The figure of merit value and Q value are 216.7 and 2187. The measured sensitivities of the metasurface samples are as follows: The sensitivity of refractive index is 0.999 THz/RIU, the sensitivity of thickness is 15.023 THz/mm, and the sensitivity of air relative humidity is 7.36 THz/RH. These measurement results validate the diverse sensing performance of this asymmetric structure metasurface and provide a basis for the development of multifunctional sensors.