Polymer brings invisibility one step closer
Physicists in Scotland say they've come up with a flexible material that brings us a small step towards "invisibility" cloaking, long the subject of science fiction and fantasy writing.
The work is in the domain of metamaterials, or compounds with a surface that interacts with light thanks to a tiny, nano-level structure.
According to the research published in Britain's New Journal of Physics, the invention, dubbed Metaflex, interacts with light at wavelengths of around 620 nanometres.
Visible light, for humans, has wavelengths ranging from 400 nanometres, where the perceived colours are violet and purple, to 700 nanometres, which is deep red.
Metamaterials are still in the prototype stage and enact their apparent shielding effect in specific wavelengths, or colours, of the light spectrum.
Flexibilty opens new avenues
The material's ability to manipulate light is what gives it its groundbreaking properties.
The research team, led by Andrea di Falco of the University of St. Andrews, made the novel material using a technique based on a commercially available polymer and a silicon support.
As a result, light flows around the object - rather like water that passes around a rock in a stream - as opposed to being absorbed by it.
The materials had previously been made from rigid substances, not flexible materials, and this limited their potential use.
"Metamaterials give us the ultimate handle on manipulating the behaviour of light," Di Falco says.
He believes Metaflex could have a wide use in optics as well as smart clothing.
In a demonstration of the substance's flexibility, the scientists placed a layer of Metaflex onto ordinary contact lenses. Just a tiny amount of the substance has been made, in order to prove the theory that a flexible metamaterial can be made.
Previous work in flexible metamaterials has yielded success in the terahertz and near-infrared parts of the electromagnetic spectrum, but this is not light that is visible to humans.