Verification of the resonance properties of the electromagnetic dipole-hybrid mode and magnetic toroidal dipole mode of the metasurface and its clothing fabric sensing performance

Here, a metasurface design strategy with high-quality factors and figure of merit (FOM) value is proposed and verified in the 4.0–20.0 THz range. By introducing symmetry breaking, the disk array is transformed into a tetramer cluster structure. The electromagnetic dipole-hybrid (ED–MD) mode and the magnetic toroidal dipole (MTD) mode are excited by the proposed metasurface. The ED–MD mode and MTD mode show high quality factors and extremely narrow bandwidth, which are beneficial for clothing fabric sensing applications. The amplitude and resonance positions can be modulated by using asymmetric parameters. The ED–MD mode exhibits a measured refractive index sensitivity of 921.25 GHz/RIU, and the corresponding FOM value is 3.56 × 104 in the clothing fabric sensing. This proposed metasurface verifies the asymmetric resonance characteristics and the clothing fabric sensing applications.