Scalable-Manufactured Metamaterials for Simultaneous Visible Transmission, Infrared Reflection, and Microwave Absorption

Abstract

Scalable manufacturing of metamaterials with multispectral manipulation capabilities remains highly challenging, which was generally circumvented by integrating several single-spectral metamaterials, potentially leading to complex processes, large thicknesses, and limited fabrication size. We experimentally demonstrate a standalone and scalable-manufactured multispectral metamaterial featuring simultaneous visible transmission, infrared reflection, and microwave absorption. The prepared multispectral metamaterial with an area of 255 cm2 exhibits a visible transmittance of 74.5% at wavelengths of 400–700 nm (the highest 80.2% at 510 nm), a thermal emissivity of 0.08 at the infrared (IR) wavelengths of 2.5–20 μm (the lowest 0.03 at 19.5 μm), and a microwave absorptance of 63.4% at frequencies of 8.2–12.4 GHz (the near-perfect 97.4% at 11.5 GHz) on average with a deep-subwavelength thickness of λ/47. The deep-subwavelength multispectral metamaterial consists of a submillimeter-thick polyethylene terephthalate dielectric spacer sandwiched by a patterned ultrathin metal and a metal mesh back-reflector with ultralow sheet resistances. Unlike the conventional optically transparent microwave absorbers made from indium tin oxides, the surface plasmonic modes can be excited within the submillimeter-thick multispectral metamaterial, bringing about the gap plasmon polaritons-induced microwave attenuation, together with the excellent visible transparency and high IR reflection/low IR emissivity. This work may inspire the designs and practical production of standalone multispectral metamaterials and benefit the protection against ubiquitous IR and microwave reconnaissance without impeding visual observation.

Bionic structures for optimizing the design of stealth materials

“…It is worth noting that some advanced metamaterials have become promising candidate materials for engineering infrared emissivity and thermal radiation, by which means compatible infrared stealth can be achieved. [57][58][59][60] 4 Bionic infrared stealth As mentioned above, current detection methods are so various that the design of RAMs for microwaves fails to meet the requirements of multispectral stealth. The most common multispectral stealth requirement is microwave absorption compatible with infrared stealth.…”

“…It is worth noting that some advanced metamaterials have become promising candidate materials for engineering infrared emissivity and thermal radiation, by which means compatible infrared stealth can be achieved. 57–60…”

Visible Transparent Wideband Microwave Meta‐Absorber with Designable Digital Infrared Camouflage

“…ITO films exhibit transparency in the visible range, and their effective relative permittivity in the IR band can be accurately described using the Drude model. [37,[38][39][40]…”

Indium tin oxide as a dual-band compatible stealth material with low infrared emissivity and strong microwave absorption

“…13,14 However, due to the great difficulty in structural design, they are relatively new concepts and still a long way from being applied. 15 Due to the strong interaction between the chains, the solubility of the conductive polymer is quite poor, which leads to its disastrous processability. 16 Therefore, doped oxide semiconductors are still the most mainstream materials in the field of compatible stealth research.…”