Fig. 1. Schematic drawing of (a) floating terahertz metamaterials and (b) common terahertz metamaterial. Schematic drawing of fluid cells with (c) floating terahertz metamaterials and (d) common terahertz metamaterial.

Fig. 2. (a) Experimental and (c) simulated spectra of floating terahertz metamaterial with air and glycerol overlayers at h=30  μm. (b) Experimental and (d) simulated spectra of common terahertz metamaterial with air and glycerol overlayers.

Fig. 3. Near-field distributions of SRRs of (a) common and (b) floating terahertz metamaterials with glycerol overlayers.

Fig. 4. SEM images of floating terahertz metamaterials with photoresist patterns at h of (a) 6.6 μm, (b) 13.4 μm, (c) 18.2 μm, and (d) 27.2 μm.

Fig. 5. Experimental spectra of floating terahertz metamaterials with air and glycerol overlayers at h of (a) 6.6 μm, (b) 13.4 μm, (c) 18.2 μm, and (d) 27.2 μm.

Fig. 6. Near-field distributions of SRRs of floating terahertz metamaterials with glycerol overlayers at h of (a) 6.6 μm, (b)13.4 μm, (c) 18.2 μm, and (d) 27.2 μm.

Fig. 7. Experimental and simulated refractive index sensitivities of floating terahertz metamaterials with air and glycerol overlayers at various floating heights.

Fig. 8. Schematic drawings of protein binding of BSA and anti-BSA on (a) floating and (b) common terahertz metamaterials. Photos of water evaporation of (c) BSA and (d) anti-BSA aqueous solutions that are dropped on floating and common terahertz metamaterials.

Fig. 9. (a) Experimental spectra of floating terahertz metamaterial at air overlayer, BSA layer, and BSA/anti-BSA layer. (b) Experimental spectra of common terahertz metamaterial at air overlayer, BSA layer, and BSA/anti-BSA layer.

Fig. 10. Dependencies of ΔfF/ΔfC on β at arbitrary α=0.2, 0.4, 0.6, and 0.8.

Fig. 11. Dependencies of ΔfF/ΔfC, which involve nlif=1.30, 1.65, and 2.25, on β at α=0.6.

Fig. 12. Cases of (a) small, (b) middle, and (c) large β in design.

Fig. 13. (a) Simulated spectra of floating SRRs with and without complementary SRR at air and glycerol overlayers. (b) Simulated spectra of single complementary SRR at air and glycerol overlayers.

Fig. 14. Schematic drawing of terahertz absorbers that involve (a) floating and (b) common SRRs.