Terahertz imaging with metamaterials for biological applications

Terahertz (THz) technology has become more widespread due to its diverse range of potential applications, particularly when combined with various functional metamaterials using cutting-edge nanotechnology techniques. In this report, we introduce a highly improved THz imaging technology by comparing complementary metamaterials intuitively based on Babinet's principle. The THz reflectance spectra for the complementary metamaterials exhibit a significant and distinct association with the polarization angle. Four different polarization angles and metamaterial pattern geometries were tested for the reflectance imaging of a target image pattern. Field enhancement on the metamaterial surface was also investigated using finite element simulations to support the experimental results. Optimizing the metamaterial based on the experimental and calculation results led to high image contrast and quality. The proposed label-free imaging platform was then employed to produce clear contrast images for mouse brain tissue and HEK-293 cells, thus highlighting the potential application of this system to real biological samples.