3D‐Printed Gradient‐Porous MXene@mRGO@SiO ₂ Microspheres/SiC Hybrid Elastomer for Broadband Electromagnetic Wave Absorption

Abstract 3D printing via direct ink writing (DIW) enables the precise fabrication of macroscale architectures for high‐performance electromagnetic wave absorption elastomers (EMWAEs). However, achieving inks that combine excellent printability with superior electromagnetic and mechanical properties remains challenging. Here, a scalable fabrication strategy employing MXene@modified‐RGO@SiO 2 microspheres synthesized through continuous spheroidization is presented. The incorporation of SiO 2 nanoparticles on the microsphere surface preserves the spherical morphology, enhances dispersion within the silicone elastomer matrix, and optimizes rheological behavior for stable DIW extrusion. Guided by electromagnetic simulations, three‐layer gradient‐porous structures is designed and printed that maximize interfacial polarization and multiple scattering effects. The resulting elastomers exhibit a minimum reflection loss (RL min ) of −44 dB and a maximum effective absorption bandwidth of 7.2 GHz at a thickness of only 3 mm. In addition to their outstanding electromagnetic performance, the printed materials demonstrate improved thermal conductivity and tensile strength, offering a multifunctional platform suitable for flexible and wearable electronic devices. This approach provides a simple, effective, and customizable route for integrating advanced fillers into 3D‐printable elastomers, paving the way for next‐generation EMWAEs with tunable architectures, broad bandwidth absorption, and mechanical robustness.