Multispectral camouflage nanostructure design based on a particle swarm optimization algorithm for color camouflage, infrared camouflage, laser stealth, and heat dissipation.

With the development of camouflage technology, single camouflage technology can no longer adapt to existing environments, and multispectral camouflage has attracted much research focus. However, achieving camouflage compatibility across different bands remains challenging. This study proposes a multispectral camouflage metamaterial structure using a particle swarm optimization algorithm, which exhibits multifunctional compatibility in the visible and infrared bands. In the visible band, the light absorption rate of the metamaterial structure exceeds 90%. In addition, color camouflage can be achieved by modifying the top cylindrical nanostructure to display different colors. In the infrared band, the metamaterial structure can achieve three functions: dual-band infrared camouflage (3-5 µm and 8-14 µm), laser stealth (1.06, 1.55, and 10.6 µm), and heat dissipation (5-8 µm). This structure exhibits lower emissivity in both the 3-5-µm (ɛ=0.18) and 8-14-µm (ɛ=0.27) bands, effectively reducing the emissivity in the atmospheric window band. The structure has an absorption rate of 99.7%, 95.5%, and 95% for 1.06, 1.55, and 10.6 µm laser wavelengths, respectively. Owing to its high absorptivity, laser stealth is achieved. Simultaneously, considering the heat dissipation requirements of metamaterial structures, the structural emissivity is 0.7 in the non-atmospheric window (5-8 µm), and the heat can be dissipated through air convection. Therefore, the designed metamaterial structure can be used in military camouflage and industrial applications.