Bio-inspired multispectral camouflage material for microwave, infrared, and visible bands based on single hierarchical metasurface.

Nature can significantly inspire humans. Chameleons, jellyfish, and many other creatures use unique camouflage methods. Multispectral camouflage materials are highly desirable to against progressive multispectral detection. The proposed structure should be simple and highly transparent to ensure a wide application range. In this study, a bio-inspired multispectral camouflage material with visible transparency, microwave diffusion, and infrared (IR) camouflage was designed, fabricated, and tested. Multispectral camouflage performance was achieved on a single metasurface by the following steps: First, a nanoscale multilayered film consisting of an oxide and metal was unitized to achieve a low IR emissivity and high visible transmittance. Then, two units were designed to obtain a phase difference, thus realizing the microwave diffusion performance. Based on the relationship between the area filling fraction and IR emissivity, the units can perform puzzled imaging under an IR thermal camera. The structural parameters were calculated and optimized through an equivalent circuit model-based artificial intelligence algorithm. Then, a 10 dB reduction in radar cross section from 7 GHz to 16 GHz, a puzzled IR thermal image, and a high optical transmittance (>0.7) were achieved. The work provides significant guidance for the design and fabrication of multispectral camouflage materials.