Fabrication of ultrathin flexible microwave shielding absorbers based on OA-γ-Fe2O3/GO synergistic superstructures

Abstract

To break through the performance bottlenecks of electromagnetic protection materials in terms of lightweight design, broadband absorption, and multifunctional integration, this work proposes a synergistic design strategy based on magneto–dielectric coupled absorbing units and periodic micro-circular array superstructures. At the microscopic scale, oleic acid (OA)-modified γ-Fe₂O₃/graphene oxide (OA-γ-Fe₂O₃/GO) composite absorbing units were constructed and organized into precisely controllable millimeter-scale periodic micro-circular arrays. Acting as an artificial electromagnetic structure capable of actively modulating the electromagnetic field distribution, the array enables multiple scattering, progressive attenuation, and continuous impedance transition within the interface, thereby significantly optimizing the energy dissipation pathways. A pressing process was employed to integrate polytetrafluoroethylene (PTFE) onto the fabric surface, realizing a high-performance composite fabric with an overall thickness of only 0.128 mm. The resulting composite exhibits outstanding performance, with a shielding effectiveness (SE_T) of 73.99 dB, a minimum reflection loss (RL_min) of −31.56 dB, and an effective absorption bandwidth (RL < −10 dB) spanning 10.93–11.83 GHz. Meanwhile, it demonstrates excellent multifunctional properties, including a water contact angle of 125.7°, a tensile strength of 142 MPa, and the retention of 93% of its initial shielding performance after 10 000 bending cycles. Compared with commercial thin shielding textiles, the proposed material achieves an improvement of over 20% in shielding effectiveness and over 30% in absorption performance. This study not only provides a high-performance electromagnetic protection material but also establishes a cross-scale “unit–structure” synergistic design framework, offering a new fundamental paradigm for developing intelligent and adaptive electromagnetic protection systems. The strategy holds great potential for applications in stealth technology, aerospace engineering, and wearable electronics.