Laser powder bed fusion printing of compound-eye inspired impedance-matched 3D all-fiber-structured SiC metamaterial for ultra-broadband electromagnetic absorption

Silicon carbide (SiC) ceramic-based composites have attracted significant attention for electromagnetic (EM) absorption under extreme environments. However, achieving the balance between impedance matching and attenuation capacity remains an urgent challenge. Inspired by the unique physiological impedance matching and light signal processing characteristics of the compound eye, a synergistic mechanism of macro impedance matching and micro attenuation has been applied to the fabrication of SiC metamaterial absorbers. The excellent impedance matching characteristic was achieved by optimizing the size parameters of frustum pyramid structures. Additionally, the strong intrinsic attenuation capacity was achieved by introducing 3D cross-linked structures constructed by micro/nano SiC fibers. Herein, the compound-eye inspired SiC metamaterial absorber was successfully generated using laser powder bed fusion (LPBF) with an optimized effective absorbing bandwidth (EAB) of 36.06 GHz (3.94−40 GHz) with a printed thickness of 12 mm. The wide-angle absorption was also realized within 0−60° and 0−70° under transverse electric (TE) and transverse magnetic (TM) polarization modes. The compound-eye inspired 3D macro/micro structure integrated strategy provides an efficient approach for the design and fabrication of broadband SiC metamaterial absorbers.