Watch: British company unveils real-life invisibility cloak
Harry Potter relied on an invisibility cloak to navigate the corridors of Hogwarts unseen - and now technology has come up with a real, working one.
The Thermal Camouflage Jacket, produced by London start-up Vollebak in collaboration with University of Manchester scientists, is the first step towards camouflaging human beings from infrared cameras.
The jacket is computer-programmable and uses graphene - a hi-tech material made of a one-atom-thick layer of carbon.
The jacket - still at the prototype stage - has 42 computer-programmable graphene patches on the front, which can be controlled individually.
Each patch is made up of more than 100 years of graphene, and control thermal radiation on the jacket’s surface without changing its temperature.
The researchers spent a week writing code that would allow us to play Tetris in infrared. So instead of seeing heat radiating from a human body, the camera simply sees the pattern of a 1980s computer game.
The researchers write, “We start by uploading code from the computer to a microcontroller on the jacket. Gold and copper printed wiring runs to each graphene patch, applying voltage to them. The voltage forces ions between the graphene layers using ionic liquid. And the more ions you push between the graphene layers, the less thermal radiation it emits and the colder it looks.
“The key detail is that every single patch can be programmed individually to emit a different level of thermal radiation. And this is the way it can blend into its surroundings and appear invisible to infrared cameras.
“Over the next decade, as we scale the technology up and scale the size of the graphene pixels down, theoretically you should be able to hide anything. With enough patches and enough power, a person could simply blend into a forest. Or a plane could blend into a runway.”
While graphene’s existence was first theorised in the 1940s, it wasn’t until 2004 that two scientists at the University of Manchester – Andre Geim and Konstantin Novoselov – were able to isolate and test it.
During their highly speculative ‘Friday night experiments,’ they peeled layer after layer off a shaving of graphite using Scotch tape until they produced a sample of graphene just one atom thick.
In 2010 their work won them the Nobel Prize.
Manchester’s National Graphene Institute and Graphene Engineering and Innovation Centre are dedicated entirely to working on the future of the supermaterial.
The researchers say that while the Thermal Camouflage Jacket only operates on the infrared spectrum today, by using graphene, it should ultimately be possible to build a version that also operates on the visible spectrum at the same time.
Graphene is a highly tuneable material, which means that applying energy to it changes how it appears on both the infrared spectrum and the visible spectrum, the researchers say.
Theoretically at least, changing the charge density of the graphene will change the colour we see.
Once you’ve got one device that controls all wavelengths, that’s when the possibility of building an invisibility cloak starts to become very real, the researchers say.