  We demonstrate a 3D printed holographic metasurface antenna for beam-focusing
applications at 10 GHz within the X-band frequency regime. The metasurface
antenna is printed using a dual-material 3D printer leveraging a biodegradable
conductive polymer material (Electrifi) to print the conductive parts and
polylactic acid (PLA) to print the dielectric substrate. The entire metasurface
antenna is 3D printed at once; no additional techniques, such as metal-plating
and laser etching, are required. It is demonstrated that using the 3D printed
conductive polymer metasurface antenna, high-fidelity beam focusing can be
achieved within the Fresnel region of the antenna. It is also shown that the
material conductivity for 3D printing has a substantial effect on the radiation
characteristics of the metasurface antenna.
