Schematic of an LC-based fast tunable TMA. (a) Rendering of the LC cell. The top fused silica substrate, which can be of any thickness, is covered with a metal ground plane, and the bottom one with a metasurface. (b) Core region of the TMA. Both the metasurface and the metal ground plane are spin-coated with SD1 alignment layers which are homogenously aligned along the x axis. The cell is filled with LC NJU-LDn-4 drawn in by capillary action, which serves as the dielectric spacer with a thickness of 15 μm. (c) Optical microscope image of the metasurface. The diameter D of each disk electrode is 130 μm, and they are connected in the x direction by metal wires with a linewidth d = 10 μm; the period of the metasurface T = 150 μm.