Tunable meta-atom using liquid metal embedded in stretchable polymer

Abstract

Reconfigurable metamaterials have great potential to alleviate complications involved in using passive metamaterials to realize emerging electromagnetic functions, such as dynamical filtering, sensing, and cloaking. This paper presents a new type of tunable meta-atoms in the X-band frequency range (8-12 GHz) toward reconfigurable metamaterials. The meta-atom is made of all flexible materials compliant to the surface of an interaction object. It uses a liquid metal-based split-ring resonator as its core constituent embedded in a highly flexible elastomer. We demonstrate that simple mechanical stretching of the meta-atom can lead to the great flexibility in reconfiguring its resonance frequency continuously over more than 70% of the X-band frequency range. The presented meta-atom technique provides a simple approach to dynamically tune response characteristics of metamaterials over a broad frequency range. V

Stretchable and Soft Electronics using Liquid Metals

“…Within the context of electromagnetic devices, liquid metals can also be used for mirrors, diffraction gratings, frequency selective surfaces, plasmonics (and reconfigurable plasmonics), metamaterials (and tunable metamaterials), and radiation shielding . The optical properties of gallium were recently measured by ellipsometry, which may be useful for these types of electromagnetic applications.…”

A single layer negative index meta atom at microwave frequencies

“…Besides it is applicable for tri (C‐, X‐, Ku) bands applications and effective medium ratio is 5 that means compact in size, flexible, etc. ; In addition, Ref were compact in size but they were only applicable for X‐band and bandwidth were one third than the proposed meta atom structure. Similarly, Ref.…”

“…Liu et al in 2015, suggested a 5 × 5 mm 2 meta atoms for X‐band and made from a liquid metal‐based split‐ring resonator embedded in an extremely flexible elastomer. This meta atom structure showed single negative properties and narrow bandwidth but the electromagnetic waves were propagating along the y‐directions . Hossain et al in 2016, displayed a double C‐shape metamaterial for tri‐band applications and the effective medium ratio was 7.14.…”

Stretchable Twisted‐Pair Transmission Lines for Microwave Frequency Wearable Electronics

“…Furthermore, modified silicone (Ecoflex) was used as the substrate, which is a suitable biocompatible elastomer for many EES, as it can be casted in ultrathin sheets and can conformally attach to the skin . It is also a suitable elastomer for RF electronics as it features relatively low RF loss tangent (tan δ = 0.01) with a dielectric constant of 2.5 at microwave frequencies . Figure g shows the camera image of the stretchable transmission line array laminated on the back of hand.…”