The role of metamaterials in future electromagnetic technologies

Rebecca Seviour, Jonathan Gratus

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

Abstract

Since the start of the twenty-first century, research into metamaterials has grown at a frantic pace, with researchers proposing new materials with increasingly more exotic properties and proposed applications. In this chapter, we aim to present an overview of the field, advantages, and exotic properties these materials can offer, and emerging application areas for these materials. The potential applications for metamaterials are diverse and promising. They have been proposed as candidates for optical filtering, medical devices, remote aerospace operations, sensor detectors, solar power management, crowd control, radomes, antenna lenses, and many more. Ultimately, this is a very broad and rich area, which, in this chapter, we can only hope to give the reader an overview of, with the hopes this inspires the reader to explore aspects presented in greater depth. From optical to RF wavelengths, the propagation and interaction of electromagnetic (EM) waves are governed by Maxwell's equations. Where at the microscopic level, these fields couple to the material they are incident on and propagate through by inducing polarization and magnetization of the atoms in the material. In Maxwell's equations, the coupling between materials and the electric/magnetic fields is described by two abstract material parameters: the permittivity e and the permeability μ. For over a hundred years, scientists have synthesized molecular materials to give tailored e and μ, determined by the movement of the light-mass negatively charged electrons surrounding the relatively large-mass positively charged nucleus of atoms in response to an EM wave forming a dipole. However, this interaction can only offer a limited range of e and μ due to the fundamental properties (charge, mass) and the chemical bonds formed by the atoms of the material. This limitation has led scientists and engineers to consider a range of artificial composite structures with periodic sub-wavelength functional inclusions. Although these inclusions are many orders of magnitude larger than the molecules of the constitutive materials, they are still much smaller than the incident EM wavelength, meaning these inclusions respond no differently than giant molecules with very large polarizability. Enabling the interactions between wave and the collective structures to be described in terms of the 'homogenized' abstracted bulk material parameters permittivity and permeability. Treating the collective periodic structures as an 'effective' material. This approach in theory allows engineers and scientists to fabricate artificial materials with specific electromagnetic properties, most notable of which is the creation of materials with simultaneously negative e and μ. There are of course still restrictions on engineered properties; for example, it is impossible to engineer a material where the group velocity of an electromagnetic EM wave is greater than the speed of light in a vacuum.

Original languageEnglish
Title of host publicationNew Waves in Electromagnetic Technology
EditorsAndrew Michael Chugg
PublisherInstitution of Engineering and Technology
Chapter3
Pages65-80
Number of pages16
ISBN (Electronic)9781839534577
ISBN (Print)9781839534560
DOIs
Publication statusPublished - 15 Apr 2025

Publication series

NameElectromagnetic Waves
PublisherInstitution of Engineering and Technology

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