A Novel Multilayer Broadband Terahertz Metamaterial Absorber Based on Three- Dimensional Printing and Microfluidics Technologies

The manufacturing of three-dimensional (3D) metamaterials remains a major challenge and the narrow-band absorption characteristics limit the practical applications of terahertz metamaterial absorbers. To this end, we propose to combine the 3D printing technology with the microfluidics technique to fabricate a terahertz (THz) metamaterial absorber with a relative broad band (∼0.3 THz) under 1 THz. Here, the absorber consists of embedded multilayer disk microfluidics channels stacked vertically within the resin and filled with liquid metal (LM). It has been demonstrated that the experimental results agree well with the simulations, where the absorber exhibits polarization sensitive and incident angle insensitive in the frequency range from 0.25 to 0.6 THz. The proposed method enables the fabrication of terahertz metamaterial devices with complex structures in a fast, simple and low-cost way, which is no longer limited to conventional photolithography processes. This approach effectively stimulates many potential applications in emerging THz technologies, such as sensing, imaging, and wireless communications.