Chemically deposited Cu nanocubes on a PUA gyroid lattice for lightweight and flexible electromagnetic interference shielding

Electromagnetic pollution poses significant risks to electronic devices and human health, highlighting the need for mechanically robust, lightweight, and cost-effective electromagnetic interference (EMI) shielding materials. 3D-printed structures with nanomaterial-engineered surfaces offer a promising method for tailoring mechanical and electrical properties through multiscale design. Herein, we present a facile strategy for fabricating lightweight and flexible EMI shielding structures by chemical deposition of nanostructured metal coatings onto 3D-printed polymeric substrates. Copper nanocube-decorated polyurethane acrylate (Cu/PUA) structures with triply periodic minimal surface (TPMS) architectures are fabricated to materialize this design. The densely arrayed nanocubes enhance electrical conductivity and enlarge the interfacial surface area, while the continuous curvature and interconnected porosity of the TPMS design promote multi-reflection and internal absorption of incident electromagnetic waves. Thus, gyroid-structured Cu/PUA achieves an average total shielding effectiveness of 76.64 dB in the X band, corresponding to an attenuation of 99.999998% of incident waves. Despite an ultralow density (0.41 g cm^-3), the material exhibits an excellent compressive strength of 0.54 MPa and a flexural strength of 0.51 MPa. This approach offers a scalable and versatile route to multiscale synergistic modification, demonstrating the potential of architected nanostructured composites for EMI shielding applications.