European researchers close in on invisibility cloak
European researchers have taken the world a step closer to fictional wizard Harry Potter’s invisibility cape after they made an object disappear using a three-dimensional “cloak”, a study published Thursday in the US-based journal Science showed.
Scientists from Karlsruhe Institute of Technology in Germany and Imperial College London used the cloak, made using photonic crystals with a structure resembling piles of wood, to conceal a small bump on a gold surface, they wrote in Science.
“It’s kind of like hiding a small object underneath a carpet — except this time the carpet also disappears,” they said.
“We put an object under a microscopic structure, a little like a reflective carpet,” said Nicholas Stenger, one of the researchers who worked on the project.
“When we looked at it through a lens and did spectroscopy, no matter what angle we looked at the object from, we saw nothing. The bump became invisible,” said Stenger.
The “cloak” they used to make the microscopic bump disappear was composed of special lenses that work by bending light waves to suppress light as it scattered from the bump, the study says.
The invisibility cloak was minute, measuring 100 microns by 30 microns — one micron being one-thousandth of a millimeter — and the bump it hid was 10 times smaller, said Stenger.
The researchers are working now to recreate the disappearing bump but on a larger scale, but Stenger said Harry Potter’s invisibility cape would not be hanging in would-be wizards’ wardrobes in the near future.
“Theoretically, it would be possible to do this on a large scale but technically, it’s totally impossible with the knowledge we have now,” he said.