Combined multi-band infrared camouflage and thermal management via a simple multilayer structure design

Abstract

Infrared camouflage is crucial for high-temperature objects to avoid detection, and spontaneous infrared radiation is also an important way for high-temperature objects to dissipate heat. Therefore, selective infrared emission has become significant for the coating design of surfaces such as aircraft, which require low emission in the atmospheric window band (3–5 µm and 8–14 µm) and high emission outside it (5–8 µm). This Letter employs a simple multilayer film structure to achieve selective regulation of the material emission spectrum. Combining the transfer matrix method and genetic algorithm, a multilayer film structure containing 12 layers of three high-temperature-resistant materials ( S i O 2 , T i O 2 and Ge) has been designed. It shows fairly low emissivity in two main bands of infrared detection ( ε 3 ∼ 5 µ m = 0.14 , ε 8 ∼ 14 µ m = 0.21 ) and high emissivity outside them ( ε 5 ∼ 8 µ m = 0.86 ), and this infrared selectivity can be well maintained with the incident angle rising from 0 to 60 deg. The Poynting vector distribution in the material at different incident wavelengths is analyzed to further explore the interference mechanism to achieve spectral selective emission. The significance of this work lies in the construction of a relatively simple coating design while ensuring efficient infrared camouflage and thermal management performance.

Porous Nanostructured Composite Film for Visible-to-Infrared Camouflage with Thermal Management

“…For infrared camouflage materials with thermal management, low infrared emissivity in these two detected bands is necessary. Meanwhile, high emissivity in the undetected band (5–8 μm) is needed for heat dissipation through radiative cooling. − To date, there have been several types of MIR spectrally selective emissivity materials, including one-dimensional photonic crystals (1D PCs), multilayer films, and metasurfaces, − which have demonstrated multiband MIR camouflage. However, the 1D PC and multilayer films suffer from larger thickness and bulkiness, leading to increased cost and poor mechanical stability.…”

Compatible Stealth Metasurface for Laser and Infrared with Radiative Thermal Engineering Enabled by Machine Learning

“…[1,[13][14][15][16][17][18] Comparing to the traditional coatings with low emittance at full infrared waveband, the selective metasurfaces maintain the low observability at atmospheric window and supply efficient radiative heat dissipation to avoid potential thermal instability. [1,[19][20][21][22][23] In addition, selective metasurfaces are promising candidates supporting compatibility with laser stealth, which is important to escape from the detection of multiband seekers such as cameras incorporating mid-infrared (MIR) imaging and near-infrared (NIR) laser active detection. [24] Generally, the simultaneous dual-band responses of metasurfaces can be achieved by reasonably combining different resonant modes.…”

Design and optimization of flexible metamaterials for microwave and infrared compatible stealth

“…The radiation energy can be reduced by controlling the surface emissivity (metal film [8] , metamaterial [9,10] , photonic crystal [11,12] ) and surface temperature (phase change material [13][14][15] , thermal insulation material [16,17] ). The suppression of IR radiation energy means that the heat diffusion is reduced, resulting in heat accumulation [18,19] in the interior and the increase of temperature [20] , so that the IR stealth effect is weakened. Researchers have proposed the use of wavelength selective emitters [21,22] , which exhibit low emissivity in the atmospheric window (3-5 m and 8-14 m) and high emissivity in the non-atmospheric window (5-8 m), suppressing IR radiation while radiating cooling and improving thermal stability.…”