As shown in Fig. and 1B, the metasurface can be toggled between high and low emissivity by modulating the optical properties of the CP spacer. The spacer, PANI-CSA, is an active CP transitioning between lossy dielectric and reflective metal when varying the doping level and oxidation state. PANI is known for the capability of undergoing Anderson-Mott transition from an insulator to a metal, exhibiting a wide range of DC conductivity from the order of 10 S/cm to up to 1100 S/cm . The counter anion serves as an extrinsic dopant and changes the electronic structure of the CP (Fig. ).