Flexible multilayer film structure for visible–laser-infrared compatible camouflage

With the rapid advancement of detection technologies, the demand for multi-band compatible camouflage solutions has significantly increased. In this study, we propose a flexible meta-coating based on a polyimide (PI) substrate, featuring a double Fabry-Perot cavity for effective camouflage across visible-near-infrared laser-infrared bands. The visible color of the structure can be tuned by adjusting the thickness of the top dielectric layer, enabling selective reflection of specific light wavelengths. In the infrared atmospheric window, the multilayer film exhibits low average emissivity (ε_3-5_μm = 0.16, ε_8-14_μm= 0.18), providing efficient thermal camouflage. Conversely, in the non-atmospheric infrared window, the film shows higher emissivity (ε_5-8μm = 0.63), facilitating effective radiation heat dissipation. Experimental results show that the surface temperature of the structure is 183.5°C when heated to 210°C, which is 17°C lower than that of an Al wafer under the same conditions. Additionally, the structure demonstrates high low reflectivity at 1.06 μm (ε_1.06_μm = 0.94) and 1.55 μm (ε_1.55_μm = 0.99), making it suitable for visible light-laser-infrared. This work provides a feasible solution for large-area, low-cost, heat-resistant, and multispectral-compatible camouflage, with potential applications in military applications.