3D Printed Biomimetic Metamaterial With Subwavelength Thickness for Continuous Broadband Ultra‐Strong Electromagnetic Wave Absorption

ABSTRACT Conventional electromagnetic (EM) wave‐absorbing metamaterials are extensively utilized in military stealth applications and signal transmission. However, the structural design and manufacturing processes remain limited, leading to research on absorbing materials primarily focusing on achieving broadband absorption of 90% of incident EM waves. Therefore, attaining ultra‐strong absorption of 99% of incident EM waves across a wide bandwidth and multiple angles poses significant challenges. Inspired by the structure of fly compound eyes and their resistance to EM wave reflection, this work designs a bionic metamaterial composed of multilayer gradient units and achieves the precise manufacturing of sub‐wavelength structures using 3D printing technology. Subsequently, high‐temperature pyrolysis is employed to regulate the EM parameters of the metamaterial, optimizing impedance matching characteristics while providing a rich dielectric loss phase. The dual impedance matching optimization design and multiple synergistic loss mechanisms endow the metamaterial with ultra‐strong EM wave absorption rates (≥99%) across a wide bandwidth (9.5 GHz) and multiple angles (0°–80°). Under transverse electric (TE) polarization, the ultra‐strong absorption rate (≥99%) bandwidth of this metamaterial at 0° and 40° is 9.5 and 10.3 GHz, respectively. Furthermore, this metamaterial exhibits excellent stealth performance, high ablation resistance, and stability against seawater corrosion, showing great potential for architectural EM wave‐absorbing and ship stealth capabilities. This work expands the design and facilitates strategies for high‐performance EM absorbers in diverse environments.