Details

Autor(en) / Beteiligte

• Kim, Taehwan
• Bae, Ji‐Yeul
• Lee, Namkyu
• Cho, Hyung Hee

Titel

Hierarchical Metamaterials for Multispectral Camouflage of Infrared and Microwaves

Ist Teil von

• Advanced functional materials, 2019-03, Vol.29 (10), p.n/a

Ort / Verlag

Hoboken: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• Camouflage is an emerging application of metamaterials owing to their exotic electromagnetic radiative properties. Based on the use of a selective emitter and an absorber as the metamaterials, most reported articles have suggested the use of single‐band camouflage, however, multispectral camouflage is a challenging issue owing to a difference of several orders of magnitude in the unit cell structure. Herein, hierarchical metamaterials (HMMs) for multispectral signal control when dissipating the absorbed energy of microwaves through the selective emission of infrared (IR) waves from the unit cell structure of the HMM are demonstrated. Integrating an IR selective emitter (IRE) with a microwave selective absorber, multispectral signal control with the large‐sized unit cell structures of up to 10 cm are realized. With an IRE, the emissive power from the HMM toward 5–8 µm is 1570% higher than the Au surface, which is preventing the occurrence of thermal instability. Furthermore, we determine that the signature levels of targeted IR waves (8–12 µm) and microwaves (2.5–3.8 cm) are reduced by up to 95% and 99%, respectively, when applying the HMM. A hierarchical metamaterial (HMM) for multispectral control is successfully demonstrated. The intermediate dielectric layer enables the integration of the microwave absorber and infrared (IR) selective emitter. The HMM shows not only signature control against the microwave and IR spectra, but also the dissipation of the reduced emitting energy through the undetected band of IR waves.