Tunable EMI shielding-thermal management ultrathin films: Asymmetric magneto-electric gradient architecture enabling shielding-flexibility synergy

Advancements across diverse technical fields are driving increasing demands for electromagnetic interference (EMI) shielding materials. The development of multifunctional EMI shielding films that reconcile high shielding effectiveness with mechanical flexibility is crucial to mitigate secondary EM pollution. This study proposes a structural design strategy that leverages intrinsic properties of distinct layers to achieve multifunctionality and enhanced overall performance. The core design comprises an asymmetric multilayer film with magnetic graphene decorated with metal-organic framework derivatives, highly conductive multi-walled carbon nanotubes, and a high-strength flexible Polyether ether ketone film as the upper, lower, and intermediate support layers, respectively. By modulating magnetic and conductive module thicknesses, the EMI shielding properties become tunable, yielding high shielding effectiveness (58.5 dB) and low reflection coefficient (R) (0.44). Meanwhile, the highly integrated packing enhances the construction of the in-plane heat transfer channels and simultaneously possesses excellent low-pressure electrothermal conversion capability and fast-response photothermal conversion performance. Finite element simulations confirm a tunable shielding mechanism and elucidate the heat-transfer and thermal-management mechanisms under high anisotropic thermal conductivity. This multilayer design achieves a critical balance of flexibility, strength, high EMI shielding/low reflection, and efficient active-passive thermal management, demonstrating significant potential for high-performance electronic applications.