Synergistic Dielectric-Magnetic Design of EGaIn/TPU/Fe3O4 Flexible Composites for Microwave Absorption

To overcome the challenges of insufficient flexibility and limited absorption performance in conventional electromagnetic wave (EMW) absorbers, this study synthesized a flexible ternary composite composed of EGaIn/TPU/Fe 3 O 4 via ultrasonic dispersion and magnetic stirring encapsulation. Due to the synergistic interaction between the liquid metal conductive network, Fe 3 O 4 magnetic loss units, and the elastic TPU matrix, the composite simultaneously exhibits excellent mechanical flexibility and EMW absorption. With 5 vol% Fe 3 O 4 loading, the composite achieves a minimum reflection loss (RL min ) of −41.4 dB and an effective absorption bandwidth (EAB) of 2.25 GHz at 1.5 mm, while maintaining outstanding mechanical properties (including tensile strength of 10.9 MPa, elongation at break of 658.7%, and elastic modulus of 3.56 MPa). This “conductive-magnetic-flexible” synergistic design provides valuable guidance for the developing of next-generation flexible stealth coatings and wearable electromagnetic shielding materials. Highlights Conductive-magnetic-flexible design is enabled by EGaIn/Fe 3 O 4 /TPU composites. Composites exhibit strong mechanical stability and wearable properties. The synergistic EGaIn/Fe 3 O 4 /TPU structure achieves excellent MA performance.