A Bioinspired Bilevel Metamaterial for Multispectral Manipulation toward Visible, Multi-Wavelength Detection Lasers and Mid-Infrared Selective Radiation

Manipulation of the electromagnetic signature in multiple wavebands is necessary and effective in civil and industrial applications. However, the integration of multispectral requirements, particularly for the bands with comparable wavelengths, challenges the design and fabrication of current compatible metamaterials. Here, a bioinspired bilevel metamaterial is proposed for multispectral manipulation involving visible, multi-wavelength detection lasers and mid-infrared (MIR), along with radiative cooling. The metamaterial, consisting of dual-deck Pt disks and a SiO2 intermediate layer, is inspired by the broadband reflection splitting effect found in butterfly scales and achieves ultralow specular reflectance (average of 0.013) over the entire 0.8-1.6 & mu;m with large scattering angles. Meanwhile, tunable visible reflection and selective dual absorption peaks in MIR can be simultaneously realized, providing structural color, effective radiative thermal dissipation at 5-8 & mu;m and 10.6 & mu;m laser absorption. The metamaterial is fabricated by a low-cost colloidal lithography method combined with two patterning processes. Multispectral manipulation performances are experimentally demonstrated and a significant apparent temperature drop (maximum of 15.7 & DEG;C) compared to the reference is observed under a thermal imager. This work achieves optical response in multiple wavebands and provides a valuable way to effectively design multifunctional metamaterials inspired by nature. A bioinspired bilevel metamaterial is proposed for multispectral manipulation with visible, multi-wavelength detection lasers and mid-infrared selective absorption for camouflage, motivated by the butterfly scales with broadband reflection splitting effect. This work not only widens the working wavebands compared to the conventional materials but also opens a bioinspired way to improve the multispectral performance of wave-functional metamaterials.image

Automated summary

This research proposes a bioinspired bilevel metamaterial for multispectral manipulation, providing a valuable way to effectively design multifunctional metamaterials inspired by nature.