Double‐Layer Structural Compatible Protective Material with Excellent Microwave Absorption and Heat Shielding Performance

Abstract

In view of the practical demands and mechanistic conflicts between microwave absorption and heat shielding compatibility, a double‐layer composite coating based on moth‐eyed hexagonal anti‐reflective structure is prepared by combining the advantages of metamaterials and coatings. The hexagonal periodic sequential configuration of the upper infrared shield layer (IRSL) can break the continuity of the electric field, induce a networked concentration of the surface current and internal electric field of the microwave absorption layer, thus optimizing the impedance matching and counteract the attenuated absorption performance due to the high dielectric IRSL. In addition, the emissivity of IRSL can be tuned artificially by changing the filler composition and particle size. The structural double‐layer composite coatings have a maximum effective absorption (reflection loss←10 dB) bandwidth of 7.4 GHz in the SKu bands at deep subwavelength thickness, while the infrared emissivity is 0.292. This work provides a novel approach for multispectral modulation in the field of advanced compatible protection systems.

Bionic structures for optimizing the design of stealth materials

“…49 (d) Surface and internal electric fields of MAL in slab and structural double-layer coating. 50 (e) Digital and SEM images of real moth-eye surface microstructures. 51 (f) Photograph of slab and bionic millimeter-scale MM absorbers.…”

“…There are also some planar moth-eye structure metamaterial absorbers with relatively low thickness. For example, Wang et al 50 prepared double-layer composite metamaterials. The periodic sequence of the surface infrared shielding layer based on the moth-eye hexagonal structure breaks the continuous concentration of the surface current, effectively optimizing the microwave impedance, and the double-layer composite structure effectively realizes infrared-radar-compatible stealth.…”

Metamaterial Absorbers with Archimedean Tiling Structures: Toward Response and Absorption of Multiband Electromagnetic Waves

“…Based on the design concept of metamaterials, the design of structural wave absorbers will alleviate the dependence of the material on its own properties and enhance the wave absorption performance through artificial design and regulation, which has great potential for development. − To this end, our group has made a series of investigations on how to effectively broaden the absorption band from the bionic perspective by combining the design concept of metamaterials. − For example, the compound eye of the Heilongjiang night moth is able to suppress the reflection of light to avoid the detection of nocturnal predators and has a clear field of view in the dark. Inspired by it, our group extracted its biological model and scaled it up to a “micromillimeter” level structure according to Maxwell’s equations, which can effectively broaden the absorption band and achieve multiband compatibility, and it has certain hydrophobicity through the micrometer-level superstructure .…”