A Metamaterial Route to Realize Acoustic Insulation and Anisotropic Electromagnetic Manipulation Simultaneously

Zhao

ACS Appl. Mater. Interfaces

et al. 2021

Self Cite

Here, we present an ultralight multilayered graphene-based metasurface for suppressing specular reflection. With the help of a joint optimization method, dual low-reflection mechanisms including absorption and random diffusion are realized within the same structure, resulting in a remarkable decrease in the backward reflected energy in an ultrabroadband range of 7.5 to 43 GHz (a relative bandwidth of 140.6%). Experiments demonstrate that our design with a thickness of approximately 3.27 mm can maintain excellent antireflection performance over a wide angle range of 0 to 45° for both TE and TM waves. Additionally, as a result of adopting low-density substrates (polyethylene terephthalate and polymethylacrylimide foam) and multilayered graphene films, the proposed metasurface shows the advantage of ultralight weight, thus opening an avenue for a number of engineering applications such as electromagnetic shielding, information security, and electromagnetic compatibility technology. In addition, owing to the natural characteristics (corrosion resistance, bending resistance, etc.) of multilayered graphene films, the proposed metasurface shows enormous potential in some particular application scenarios with harsh conditions.

Section: ■ Introductionmentioning

confidence: 99%

Multilayered Graphene-Assisted Broadband Scattering Suppression through an Ultrathin and Ultralight Metasurface

Zhao

ACS Appl. Mater. Interfaces

et al. 2021

Self Cite

“…The mechanism of these optical devices is based on tuning their refractive index by designing an optimal macrostructure . With the variation of refractive index, a series of optical characteristics, e.g., reflection, absorption, and transmission, also change in corresponding frequency regions . Such a strategy to fabricate optical materials with a controllable refractive index can be adopted in designing similar materials for microwave shielding .…”

Section: Introductionmentioning

confidence: 99%

A Flexible Microwave Shield with Tunable Frequency‐Transmission and Electromagnetic Compatibility

Yang

Ong

et al. 2019

Adv Funct Materials

333

Wireless techniques have improved life quality for many. However, the drawbacks like instable signal and high loss in air of electromagnetic interference hinder its further development. One solution is to develop a smart material or device, which can selectively receive a specific frequency (f s ) of electromagnetic wave with less loss, and simultaneously show effective shielding against unwanted waves (frequency is denoted as f p ). A bottleneck has been reached, such that using materials alone is unable to achieve the above due to the limitation of the intrinsic physical properties of materials. Here, a strategy combining the material structure design with a voltage control is proposed to overcome the limitation of materials toward the aforementioned task. The efforts are focused on exploring a suitable electrically tunable material with a sensitive response to an external voltage and the flexibility to be engineered to the needed macrostructure. As a result, the f s region can be fine-tuned to 8-8.

Applied Physics Letters

“…Although the superlens for one kind of wave has been well demonstrated [1][2][3][4][5][6][7][8][9][10][11][12][13][14], the multiphysics manipulations [15][16][17] are much less explored and remains a challenging issue to be investigated and elucidated. Here, we propose a concept for a bifunctional superlens with simultaneous controls of flexural and acoustic waves.…”

mentioning

confidence: 99%

Bifunctional superlens for simultaneous flexural and acoustic wave superfocusing

Zhu

Cao

Merkel

et al. 2020

Superfocusing of acoustic and elastic waves is generally achieved by the combination of negative refraction and the enhancement of the evanescent waves. Here, we numerically and experimentally demonstrate the bifunctionality of a superlens that is able to simultaneously focus acoustic and flexural waves beyond the diffraction limit. The designed structure is composed of a two-dimensional arrangement of pillars that act as rigid scatterers for the sound waves and as resonant scatterers for the flexural waves. The band structure presents modes with negative dispersion bands allowing negative refraction for both types of waves within the frequency range 6.9-7.4kHz, which is induced by Bragg scattering effect. Edge modes that enhance the evanescent waves through resonant coupling appear around 7.2kHz for the flexural and sound wave. The simultaneous superlensing is then observed at this frequency. Our finding will enlighten multi-physical and multi-functional wave manipulations, and could have pragmatic applications involving multi-wave devices.