Digitally Coded, Screen-Printed Flexible Metasurfaces for Tunable Electromagnetic Responses

We describe a strategy for fabricating programmable metasurfaces with binary spatial material coding on flexible polyethylene terephthalate (PET) substrates. It is based on a low-cost, environmentally friendly screen-printing technique to produce digitally coded metasurfaces. Fabrication is streamlined using simple tools such as a CO₂ laser cutter and adhesive photo paper to create custom stencil masks that define binary "0" and "1" patterns for metal ink deposition. We demonstrate multiple prototypes with distinct electromagnetic functionalities, including polarization-sensitive and frequency-selective transmission. Both experimental and numerical characterizations under transverse electric and transverse magnetic (TM) polarizations reveal very good agreement. To confirm the feasibility of our approach for wireless communication systems, we employed 64-QAM digitally modulated signals and analyzed the resulting constellation diagrams. Polarization selectivity was clearly evidenced: at 8.5 GHz, the TE-polarized transmission yielded an error vector magnitude (EVM) of 3.21 (transmission of -8.30 dB), while TM polarization resulted in severe signal degradation, with an EVM of 28.83 (transmission level of -37.86 dB). Furthermore, we assessed the metasurface performance under mechanical deformation using a semicircular curvature. The results confirm the robustness of the electromagnetic response under bending, highlighting the suitability for nonplanar surfaces. Overall, the low-cost, scalable methodology introduced here allows for producing digitally programmable metasurfaces using accessible tools and materials, offering a platform for real-world electromagnetic wave manipulation and wireless communication applications.