It's been a staple of science fiction for years -- and a dream of scientists for nearly as long. Now researchers have taken a big step toward making a working invisibility cloak.
Scientists in the UK have developed a breakthrough flexible film that means Harry Potter’s “cloak of invisibility” is more scientific reality than magical wizardry, according to a report in the New Journal of Physics.
The novel material, called “Metaflex,” is composed of microscopic structures that form a “metamaterial” that has the ability to control and channel the flow of light on a fundamental level.
"Metamaterials give us the ultimate handle on manipulating the behavior of light," said Andrea Di Falco of the University of St Andrews, the lead author of the paper.
This ability to manipulate light is what allows metamaterials to create the illusion of invisibility -- a concept already applied to a number of fields including sonar-cloaking mechanisms for ships, submarines, and planes. Take the Stealth bomber for example, a plane that can be seen in visible light yet is difficult to detect with radar.
Achieving the effect in visible light is a much greater challenge, however, because the size of the metamaterial structures would have to be much smaller, according to Di Falco.
The laws of optics deem that light waves can be manipulated only by structures similar in size to their wavelength. Flexible metamaterials have been produced, but only in the high wavelength spectrum of light -- limiting the effect the deep reds.
She and her team have made a big step forward with Metaflex -- metamaterials small enough to interrupt visible light while also having the flexibility to accommodate clothing.
But recreating Harry Potter’s invisibility cloak isn’t high on the team’s agenda. Instead, they’re eager to apply the concept to disposable contact lenses as visual prostheses for people with impaired vision.