by Neal Wallace
Harry Potter’s famous invisibility cloak may not be quite as far fetched as it seems, after scientists in the UK demonstrated a flexible film, which can make objects appear invisible.
The team, from the University of St. Andrews, demonstrated the film’s, called “Metaflex”, flexibility, by using a tiny amount on a contact lens, can . It works by interrupting and channeling the flow light, rendering objects invisible, much in the way an invisibility cloak might.
Scientist Andrea Di Falco, who wrote the paper concerning the material, said: “The first step is imagining first of all that this could be done. All the typical results have been reached in flat and rigid surfaces because this is the legacy of the procedures used to create nanostructures.”
This is not the first time flexible metamaterials have been made, with previous attempts only able to work for light with a much longer wavelength – a far redder colour – than humans can see. This is because metamaterials are easier to construct when they have relatively large structures, and so only work at the Terahertz and near-infrared ends of the electromagnetic spectrum.
Metaflex works in a similar way to water bending round a rock in a stream. Thanks to a composition of tiny nano-structures, it interacts with the light, causing it to bend around the object, rather than absorbing it.
According to professor Ortwin Hess, at Imperial College London, the next step is to manipulate the material’s optical for use in options and cameras. He described the team’s success as a “huge step forward”.
Di Franco insists there is still a long way to go before people will be able to sneak around Hogwarts undetected: “So far he’s had to live in a house and now he can live in something like a tent; it’s not the cloak that adjusts to his shape, but it’s a bit more flexible. Now we have to take the next step forward.”