Light-manipulated phase change materials for multi-functional thermal camouflage

Adaptive thermal camouflage which is bioinspired and used to avoid infrared detection plays a crucial role in the military field. However, compared with mature infrared detection methods, it still has challenges to achieve adaptive thermal camouflage and imaging manipulation of object. In this paper, we experimentally demonstrate a 440-nm-thick Ge₂Sb₂Te₅ (GST) metamaterial with continuous changed average emissivity from 15% to 66% in the wavelength range of 7.5–14 μm. The precise (⪆10 states) and fast (⪅10 ms) manipulation for phase-change character of GST is achieved by laser irradiation. Combining Emissivity Engineering (EE) and Phase Change Materials (PCMs), the proposed metamaterial can be employed to multi-functional thermal camouflage device, which can simultaneously realize some functions including adaptive thermal camouflage, illusion and messaging without changing the structural parameters. The proposed PCM-based thermal camouflage metamaterials have promising potentials for applications in the field of multi-functional thermal camouflage, thermal imaging and thermal management.