Everyone’s favorite invisibility cloak concept is continuing to move forward in the UK as scientists demonstrate a flexible film that contains tiny structures that together form a “metamaterial.” This metamaterial can manipulate light in such a way that renders objects invisible – metamaterials like the one currently under examination have been created before, but only worked for light of a color beyond what a human can see with the naked eye. This new bendy approach (for visible light) is reported in the New Journal of Physics.
The reason invisibility is so difficult to attain is the fact that the laws of optics say waves are only manipulatable by structures as large as the waves length. Because of this, nanostructures (very tiny) need to be manufactured to match the tiny size of light waves.
The author of the paper in the New Journal of Physics explaining the technology, Andrea Di Falco of St Andrews University, says so very rightly, is “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.”
In the past she speaks of, stacks of “fishnet” structures have always been built on top of brittle and hard silicone. What the doctor involved in this new project, Dr Di Falco, has done is to use a thin polymer film instead. Physicist Ortwin Hess, Leverhulme Chair in Metamaterials at Imperial College London, had the following to say to the BBC about the project:
“It clearly isn’t an invisibility cloak yet – but it’s the right step toward that,” noting the next step to be characterizing the change in the material’s optical properties as the material bends and folds. BBC notes that properties such as this could, if sensitive to movement, lead to next-generation lenses for handheld cameras. On the other hand, BBC notes, if the material were not bendable at all, the films could be used in contact lenses. Proffessor Hess said this technology was still far down the road, but is somewhere in the future. “Harry Potter has to wait still – that’s the huge goal,” he said.