Plant stem inspired gradient structured composite aerogel enabling green EMI shielding, radar stealth and thermal management.

With the rapid iteration from 5G to 6G technology and the advanced integration of high-power electronic devices, electromagnetic interference (EMI) has emerged as a critical bottleneck restricting equipment reliability and the stealth performance of military hardware. Conventional shielding materials not only readily cause secondary pollution because of their high surface reflectivity, but also fall short of simultaneously meeting multiple requirements, including lightweight design, thermal management and infrared stealth. To address these challenges, inspired by the porous structure of plant stems, a gradient-structured composite aerogel featuring a conductive-magnetic dual network was fabricated via electrospinning and freeze-drying techniques. The gradient layer design progressively optimized impedance matching, thereby creating an absorption-dominant green EMI shielding mechanism. The results show that the composite aerogel achieves a high EMI shielding effectiveness of 60.98 dB and a low reflectivity of 12.54% over the 8.2-12.4 GHz. This effectively prevents secondary electromagnetic pollution while also delivering excellent radar stealth performance, with a minimum reflection loss (RLmin) of -39.6 dB. Additionally, the as-prepared composite aerogel integrates exceptional electrothermal and photothermal conversion capabilities (with a steady-state temperature exceeding 110 °C) along with remarkable thermal insulation properties. Consequently, this study provides a promising technical pathway for the development of lightweight, low-reflection and multifunction-integrated EMI shielding materials, demonstrating broad application prospects in aerospace, military camouflage and wearable electronics.