Solid‐Liquid Alternating Bicontinuous Nanocomposite Film Uniting Ultrahigh Electromagnetic Interference Shielding, Mechanical Durability and Adaptive Infrared Camouflage

ABSTRACT 5G high‐power microelectronics require integrating electromagnetic interference (EMI) shielding, heat dissipation, mechanical durability, and infrared (IR) camouflage for diverse applications. Conventional materials, however, suffer performance trade offs from lacking synergistic effects between components. We have ingeniously designed a solid‐liquid alternating bicontinuous (S‐LAB) structure, which consists of a strongly coupled PEDOT:PSS@CNTs (PC) as the solid phase, polyvinyl alcohol and liquid metal (PLM) as the liquid phase, alternating with each other. The PC hydrogel exhibits reversible swelling and ion‐anchoring functionality. LM nanoparticles dispersed in polyvinyl alcohol are injected and immobilized between the PC layers through ion interactions. The LM incorporation significantly enhances electrical conductivity, electron mediated thermal transport, and flexibility. The S‐LAB design endows the PCPLM film with exceptional strength and toughness, and cooperative electron‐phonon thermal transport. Concurrently, the π‐π stacking PC hydrogel and the PC/LM bicontinuous heterogeneous interface greatly attenuate incident EM waves, enabling synergistic multi‐property enhancement. The PCPLM nanocomposite film exhibits: an electrical conductivity reaching 5317 S cm −1 , EMI shielding efficiency (SE) of 97.6 dB, 292.8 MPa tensile strength, 29.1 MJ m −3 toughness, and 28.31 W m −1 K −1 thermal conductivity, stable SE under extreme conditions, rapid temperature adaptation enabling passive/active IR camouflage, along with excellent energy conversion efficiency and de‐icing functionality.