Water: Promising Opportunities For Tunable All-dielectric Electromagnetic Metamaterials

Abstract

We reveal an outstanding potential of water as an inexpensive, abundant and bio-friendly high-refractive-index material for creating tunable all-dielectric photonic structures and metamaterials. Specifically, we demonstrate thermal, mechanical and gravitational tunability of magnetic and electric resonances in a metamaterial consisting of periodically positioned water-filled reservoirs. The proposed water-based metamaterials can find applications not only as cheap and ecological microwave devices, but also in optical and terahertz metamaterials prototyping and educational lab equipment.

Experimental demonstration of water based tunable metasurface

“…7 Surprisingly enough, but one of the most abundant, easily reconfigurable and by default nature-friendly material on Earth, namely, water has been considered as a material platform for microwave metamaterials only very recently. [9][10][11] In this frequency range water has high dielectric permittivity e, which in addition heavily depends on temperature T. 12 In the normal laboratory conditions, water is a liquid in the large temperature range between 0 and 100 C. As such, it preserves its volume, but takes the shape provided by a container, which minimizes its potential energy (thus the surface of water in rest is flat besides the wetting effect).…”

“…Andryieuski et al 9 proposed to use the properties of water for tunable transmission of electromagnetic waves through a system of partially filled water meta-atoms. Tunability is provided by the gravity force, which readily reshapes the water volume in each elementary reservoir with rotation of the whole system of the meta-atoms.…”

Dielectric Properties of Beverages (Tamarind and Green) Relevant to Microwave‐Assisted Pasteurization

“…The values of ε s ranged from 68 to 90 for tamarind drink and from 66 to 90 for green drink. For both beverages, the ε inf converged at lower frequencies to about five, in line with the values of pure water (Andryiesku, Kuznetsova, Zhukovsky, Kivshar, & Lavrinenko, 2015). The values of relaxation time, in the order of picoseconds (ps), ranged from 6.5 to 15.9 ps for tamarind and from 6.6 to 14.8 ps for green beverage.…”

Toroidal Dipole Mode Observation In Situ

“…It is very convenient for applications due to controllable properties, namely adaption to any geometry in volume and mechanical, thermal, and gravitational tunability, dramatic dependence of permittivity on the temperature and pressure, and, obviously, ecologically friendliness. In fact, water is an available elementary component for laboratory prototyping of electromagnetic effects, such as Mie resonance in all‐dielectric particles, phase diagrams in nanophotonics, perfect absorbers, etc . Since water is a liquid‐state dielectric, we have a chance to “look into” water metamolecules to find out what exactly happens with electromagnetic fields inside dielectrics as well as to confirm the theory of Mie scattering on dielectric particles and even legitimize Maxwell's theory describing the behavior of electromagnetic waves in dielectrics.…”