High-resolution electrohydrodynamic jet printing for the direct fabrication of 3D multilayer terahertz metamaterial of high refractive index

The fabrication of 3D metamaterials, such as multilayer structures, is of great interest in practical applications of the metamaterial. Here we present an electrohydrodynamic jet printing technique as a direct fabrication method of 3D multilayer metamaterial. By alignment of the nozzle movement, we could fabricate multiple layers of the metamaterial. Controlling an electrical pulse to make droplets on-demand, we fabricated a high refractive index metamaterial and compared the optical performances of a single layer and multiple layers, with 10 μm width and 5 μm gap of I-shaped meta-atoms on the polyimide substrate. The peak refractive index was 25.7 at 0.46 THz for a four-layer metamaterial.