Optimized Microwave Absorption and Structural Compression Sensing via Magnetic Fiber-Infused Aerogels with Reduced Graphene Oxide and Carbon Frameworks

Microwave absorption materials have been engineered with a range of desirable properties, including lightweight, thin profiles, broad absorption bands, and strong absorption capabilities. However, the complex service environment is posing challenges on microwave absorption devices and equipment structure deformation sensing, necessitating innovative solutions to maintain safe operation. Herein, a 3D porous composite aerogel with magnetic fibers and reduced graphene oxide was designed and prepared via a freeze-drying method. This aerogel exhibits exceptional microwave absorption performance and effective structural deformation sensing capabilities. The composite aerogel containing 11.11 wt % magnetic fibers and subjected to heat treatment at 800 °C achieves remarkable microwave absorption with a minimum reflection loss (RLmin) of −59.6 dB at a thickness of 1.9 mm and an effective absorption bandwidth (EAB) of 5.48 GHz at 2.0 mm. Additionally, the radar cross-section (RCS) value of this aerogel coating on a perfectly electrically conducting (PEC) surface is reduced by 26.81 dBsm. The superior microwave absorption performance is attributed to the aerogel’s 3D porous structure, which facilitates multiple reflections; the magnetic fibers, which contribute to magnetic loss; and the reduced graphene oxide, which enhances electric loss. Furthermore, the aerogel exhibits notable piezoresistive properties, with a 60% reduction in resistivity at a 10% compression strain. The integration of optimized microwave absorption capabilities and advanced piezoresistive properties presents an innovative solution for radar stealth surface deformation sensing, significantly enhancing equipment survivability in demanding operational environments.