Hear out, world, invisibility cloaks are now a reality, albeit on the microscopic level – researchers in the US have achieved the feat . Find the descriptions of the research in the journal Science.
Photo credits: Berkeley Lab.
Invisibility cloaks might not be restricted to the Harry Potter world as scientists are trying to develop techniques manipulating how light hits objects to make them look inconspicuous. Recently, researchers from the Berkeley Lab in the US seem to have made a giant step forward in that direction: they created an ultra-thin invisibility ‘skin’ cloak that can be used to hide 3D objects from detection via visible light.
It is to be noted, though, that the cloak only applies to microscopic objects. Coated with a thin layer of gold nanoantennae 80-nanometres-thick, it is capable of making objects of the size of several biological cells invisible. When the materials are wrapped in it, their 3D shape is kept hidden by reflecting light waves.
“This is the first time a 3D object of arbitrary shape has been cloaked from visible light,” said Xiang Zhang, director of Berkeley Lab’s Materials Sciences Division, in a press release. “Our ultra-thin cloak now looks like a coat. It is easy to design and implement, and is potentially scalable for hiding macroscopic objects.”
The cloak is made of metamaterials whose physical structure allows them to bend or curve light reflection. The objects they “cloak” can thus be optically unidentifiable. As light rays hits the activated cloak, its reflection is distorted by the nanoantennae from the object wrapped in the cloak. The object will look flat and invisible only if seen from the front; on the other hand, any movement (by the viewer or the object) would break the optical illusion.
Do not get too excited yet for the cloak would not be practical to use for other than microscopic materials.
“If you wanted to cloak your body, you’d have to carry this thing that’s three to four times the size of your body around with you wherever you go,” said Zhang in a statement to The Guardian.
Still, Zhang is hopeful.
“It’s the first time we’ve done arbitrary shape cloaking,” said Zhang. “If you want to cloak people, that is possible with this new work.”