Bioinspired Directionally Porous Alumina Ceramics With High Reflectivity and Strength for Extreme Laser Protection

ABSTRACT High‐energy laser protection requires materials that combine ultrahigh reflectance with robust mechanical strength. Inspired by the anisotropic porous structure within the scales of the Cyphochilus beetle, this work proposes a “directionally porous photonic structure” design strategy for alumina ceramics. Using a rolling–extrusion process, we successfully construct a highly aligned network of flattened pores within the ceramic matrix. This bioinspired architecture achieves a reflectance exceeding 99% at the 1070 nm wavelength and exhibits exceptional laser protection capability, withstanding 60 s of continuous laser irradiation at a power density of 3500 W/cm 2 without surface damage. The material also exhibits excellent thermo‐mechanical stability under repeated thermal cycling. Moreover, the uniform, fine‐pore structure enables a high compressive strength of 330 MPa at 38.5% porosity, surpassing other porous alumina ceramics of comparable porosity. This study provides a novel bio‐inspired design concept and a feasible fabrication route for developing high‐performance laser‐protection materials capable of functioning in extreme environments.