Optically Transparent Metasurface Absorber Based on Reconfigurable and Flexible Indium Tin Oxide Film.

In this paper, we present a flexible, breathable and optically transparent metasurface with ultra-wideband absorption. The designed double layer of indium tin oxide (ITO) films with specific carved structure realizes absorption and electromagnetic (EM) isolation in dual-polarization, as well as good air permeability. Under the illumination of x- and y-polarization incidence, the metasurface has low reflectivity and transmission from about 2 to 18 GHz. By employing ITO film based on polyethylene terephthalate (PET), the presented metasurface also processes the excellent flexibility and optically transparency, which can be utilized for wearable device application. In addition, the dual-layer design enables mechanically-reconfigurable property of the metasurface. The transmission and reflection coefficients in two polarizations show distinct difference when arranging the different relevant positions of two layers of the metasurface. A sample with 14*14 elements is designed, fabricated and measured, showing good agreement with the simulation results. We envision this work has various potentials in the wearable costume which demands both EM absorption and isolation.