From Flexible and Stretchable Meta-Atom to Metamaterial: A Wearable Microwave Meta-Skin with Tunable Frequency Selective and Cloaking Effects

Abstract

This paper reports a flexible and stretchable metamaterial-based “skin” or meta-skin with tunable frequency selective and cloaking effects in microwave frequency regime. The meta-skin is composed of an array of liquid metallic split ring resonators (SRRs) embedded in a stretchable elastomer. When stretched, the meta-skin performs as a tunable frequency selective surface with a wide resonance frequency tuning range. When wrapped around a curved dielectric material, the meta-skin functions as a flexible “cloaking” surface to significantly suppress scattering from the surface of the dielectric material along different directions. We studied frequency responses of multilayer meta-skins to stretching in a planar direction and to changing the spacing between neighboring layers in vertical direction. We also investigated scattering suppression effect of the meta-skin coated on a finite-length dielectric rod in free space. This meta-skin technology will benefit many electromagnetic applications, such as frequency tuning, shielding, and scattering suppression.

Compact Left-Handed Meta-Atom for S-, C- and Ku-Band Application

“…In 2015, Alam et al suggested an 8 × 8-mm 2 "hexagonal" DNG metamaterial, where the bandwidth was 1.75 GHz (from 1.68-3.43 GHz) and 0.96 GHz (from 5.04-6.0 GHz) [4]. In 2016, Yang et al demonstrated a "ring-shaped" 5 × 5-mm 2 meta-atom for wearable, flexible and stretchable microwave meta-skin, with clocking effects from 8-13 GHz and an effective medium ratio of six [5]. In 2016, Du et al presented a left-handed metamaterial created by the combination of ferrite sheets and dielectric rods to investigate the electromagnetic properties for X-band applications [20].…”

“…The dimensions of the designed meta-atom are 10 × 10 mm 2 , which is compact in size according to the effective medium ratio and comparison with [5,17,19,[21][22][23]. The proposed meta-atom unit cell and arrays also exhibit more frequency bands with a wider bandwidth than [1, 4,5,16,17,[19][20][21][22][23]. Moreover, the proposed meta-atom is used for enhancing the antenna bandwidth, number of frequency bands and gain because the number of frequency bands, bandwidth and gain of the antenna can be improved by using the partial or slotted or fractal or meta-atom integrated ground plane.…”

“…Benefiting from these novel properties, meta-atoms have produced many exotic effects in several applications, such as negative permeability, sub-wavelength imaging super-lens, electromagnetic absorbers [1], negative refraction [2], filter design [3], antenna performance enhancing, SAR reduction [4] and invisible cloaking [5]. The development of the meta-atoms utilizes the intrinsic loss of the system, with the help of structural design, to obtain a wide bandwidth or sharp resonance at a certain frequency.…”

Parametric studies on split S-shaped composite meta atom for X-band communication

“…From Table 8, the bandwidth of the designed meta atom is 3.70 GHz, which is almost threefold of that in [8]. However, the bandwidth has increased by almost 12.16%, 61.89%, 28.38%, and 58.64% of those in [9], [10], [11], and [12], respectively. …”

“…the bandwidths cover 3.70 GHz and 2.22 GHz, respectively. The proposed meta-atom unit cell shows a larger bandwidth than the reference prototypes [8][9][10][11][12] and exhibits double negative characteristics of the resonance frequency. Besides, here a parametric study has been performed to demonstrate the effects of inductance and capacitance on resonance frequencies.…”