Recently, camouflage technology has attracted researchers’ attention in a large variety of thermal applications. As a special phase change material (PCM), vanadium dioxide (VO2) is an excellent candidate for the studies conducted on thermal camouflage technology. VO2 has a transition from the insulator phase to the metal phase with the increase of the temperature. With regards to this unique feature, VO2 can contribute dynamic properties to the camouflage design. In this paper, a PCM–dielectric based metamaterial mid-infrared adaptive thermal camouflage nanoantenna is designed to perfectly mimic the atmospheric windows. The adaptive property of the proposed structure is obtained by using an ultrathin VO2 interlayer embedded within the grating. The spectral responses of the structure are computed using the finite difference time domain method, and the invisibility of the structure is proved using power calculations in the different mid-infrared regions.

In an ideal platform for camouflage compatible cooling, the thermal emitter should be a spectrally selective antenna to radiate its heat buildup without being detected by thermal cameras. Moreover, to keep its visual appearance and to minimize solar induced heating, the structure should be visibly transparent. In this Letter, to achieve the visually invisible mid-infrared (MIR) camouflage-cooling feature, a metasurface design based on an indium-doped tin oxide (ITO)-hexagonal boron nitride (hBN) heterostructure is proposed. The proposed ITO-hBN nanoantenna shows spectrally selective broadband absorptions in near-infrared (NIR) and non-transmissive (MIR) windows, while it is dominantly non-emissive in other ranges. The camouflage ability of the structure in the targeted wavelengths is demonstrated using power calculations.

In this Letter, a dynamically tunable metasurface, which is based on antimony trisulfide, is introduced. In this structure, first a metal-insulator-metal (MIM) nanocavity is optimized in a way that, upon phase change, the visible response switches from a transmissive colored window into a reflective mirror. Later, an indium tin oxide nanoantenna is integrated on the MIM cavity to provide antireflection in the short-wave infrared (SWIR) range for SWIR mode thermal camouflage. The MIM host acts as a thermally tunable substrate to tune the SWIR response of the design.

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