Broadband and Multiband Terahertz Metamaterials Based on 3-D-Printed Liquid Metal-Filled Microchannel

Recently, 3-D metamaterials with intricate geometries have received an ultrawide range of attractions due to the additional degrees of freedom to manipulate electromagnetic waves and thus expand the functionalities of metadevices. Nevertheless, the fabrication of 3-D metamaterials in the terahertz (THz) regime remains to be challenging. Here, we have proposed a simple and effective method to fabricate those 3-D metamaterials by integrating 3-D printing technology and liquid metal filling process. As a proof of concept, two kinds of typical metamaterials with broadband and multiband characteristics are fabricated by the as-presented fabrication strategy. The former consists of multilayer disks while the latter is comprised of orthogonally crossed vertical split rings. Experimental measurements validate that the physical responsive spectra agree well with the theoretical simulation. Given the simple and low-cost features of our proposed fabrication method for THz metamaterials, this method provides a promising approach for the development of THz meta-devices.