Switchable VO₂ Metamaterial Based on Planar and Vertical Split Ring Resonators for High-Performance Sensing

We design a structure that combines planar and vertical split ring resonators (VSRRs). The numerical results show that the structure has excellent four-band transmission performance and exhibits an excellent quality-factor (Q-factor) of 1092 for the TE mode. The transmission performance of the proposed hybrid structure is systematically analyzed by comparing it with the performance of three other separate structures. The transmission mechanism is analyzed by finding the magnetic and electric distributions of the proposed structure in cross-profile. Our proposed hybrid structure exhibits a high-performance sensing characteristic by overlapping an analyte on it. In the structure, we use a vanadium dioxide (VO2) thin film as the bottom layer, which allows our proposed structure to act as a modulator. When VO2 is in a metallic state, the proposed structure exhibits absorption properties, while it exhibits transmission properties when the VO2 is in an insulating state. Finally, we also analyze the robustness of the structure. The results of our research may have potential applications in terahertz (THz) modulators and ultrasensitive sensors.