Optimized Microwave\nAbsorption and Structural Compression\nSensing via Magnetic Fiber-Infused Aerogels with Reduced Graphene\nOxide and Carbon Frameworks

Microwave absorption materials have\nbeen engineered with a range\nof desirable properties, including lightweight, thin profiles, broad\nabsorption bands, and strong absorption capabilities. However, the\ncomplex service environment is posing challenges on microwave absorption\ndevices and equipment structure deformation sensing, necessitating\ninnovative solutions to maintain safe operation. Herein, a 3D porous\ncomposite aerogel with magnetic fibers and reduced graphene oxide\nwas designed and prepared via a freeze-drying method. This aerogel\nexhibits exceptional microwave absorption performance and effective\nstructural deformation sensing capabilities. The composite aerogel\ncontaining 11.11 wt % magnetic fibers and subjected to heat treatment\nat 800 °C achieves remarkable microwave absorption with a minimum\nreflection loss (RL<sub>min</sub>) of −59.6 dB at a thickness\nof 1.9 mm and an effective absorption bandwidth (EAB) of 5.48 GHz\nat 2.0 mm. Additionally, the radar cross-section (RCS) value of this\naerogel coating on a perfectly electrically conducting (PEC) surface\nis reduced by 26.81 dBsm. The superior microwave absorption performance\nis attributed to the aerogel’s 3D porous structure, which facilitates\nmultiple reflections; the magnetic fibers, which contribute to magnetic\nloss; and the reduced graphene oxide, which enhances electric loss.\nFurthermore, the aerogel exhibits notable piezoresistive properties,\nwith a 60% reduction in resistivity at a 10% compression strain. The\nintegration of optimized microwave absorption capabilities and advanced\npiezoresistive properties presents an innovative solution for radar\nstealth surface deformation sensing, significantly enhancing equipment\nsurvivability in demanding operational environments.