Multifunctional-hierarchical flexible metasurface with simultaneous low infrared emissivity, broadband microwave absorption, and dynamic visible camouflage

Sophisticated multispectral detectors have made single-band camouflage materials ineffective, consequently leading to significant advancements in metasurfaces that possess both infrared (IR), radar, and visible stealth capabilities. However, the mutual constraints of stealth principles across different bands and the demand for environment-adaptive camouflage raise challenges to existing multispectral compatible stealth solutions. Here a multifunctional- hierarchical flexible metasurface (MHFM) including an infrared suppression layer (IRSL), three microwave absorbing layers (MAL), an environmental adaptation layer (EAL), and a total reflective sheet (TRS), was designed to simultaneously achieve IR, radar, and dynamic visible stealth. Unlike the direct stacking of functional layers in existing solutions, the EAL is directly integrated with the first MAL as a part of the absorbing structure. As a proof-of-concept, an MHFM sample with an area of 300 x 300 mm2 and a minimum linewidth of 20 mu m is demonstrated. The excellent multispectral camouflage performance is verified in experiments, showing low infrared emissivity (0.229, covering the wavelength of 3 similar to 14 mu m), the high absorption efficiency of over 90% in 2.53 similar to 34.56 GHz, and dynamic camouflage in both grassland and desert environments. Our work presents a new solution for adaptive visible camouflage and competitive IR-radar stealth that is prospectively applicable in complex environments. (c) 2024 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement