A 3D illustration of a metasurface skin cloak made from an ultrathin layer of
nanoantennas (gold blocks) covering an arbitrarily shaped object.
Light reflects off the cloak (red arrows) as if it were reflecting off a flat mirror.
Berkeley Lab Researchers Create Ultrathin Invisibility Cloak
(September 17, 2015) Invisibility cloaks are a staple of science fiction and fantasy, from Star Trek to Harry Potter, but don’t exist in real life, or do they? Scientists at the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have devised an ultra-thin invisibility “skin” cloak that can conform to the shape of an object and conceal it from detection with visible light. Although this cloak is only microscopic in size, the principles behind the technology should enable it to be scaled-up to conceal macroscopic items as well.
Working with brick-like blocks of gold nanoantennas, the Berkeley researchers fashioned a “skin cloak” barely 80 nanometers in thickness, that was wrapped around a three-dimensional object about the size of a few biological cells and arbitrarily shaped with multiple bumps and dents. The surface of the skin cloak was meta-engineered to reroute reflected light waves so that the object was rendered invisible to optical detection when the cloak is activated.
(From left) Yuan Wang, Zi Jing Wong and Xiang Zhang have devised an ultra-thin
invisibility “skin” cloak that can conform to the shape of an object and conceal it
from detection with visible light. (Photo by Roy Kaltschmidt)
“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 and a world authority on metamaterials – artificial nanostructures engineered with electromagnetic properties not found in nature. “Our ultra-thin cloak now looks like a coat. It is easy to design and implement, and is potentially scalable for hiding macroscopic objects.”
Now you see it, now you don’t, invisibility cloak makes 3D object disappear.
Click to see gif. (Courtesy of Zhang group)
Zhang, who holds the Ernest S. Kuh Endowed Chair at UC Berkeley and is a member of the Kavli Energy NanoSciences Institute at Berkeley (Kavli ENSI), is the corresponding author of a paper describing this research in Science. The paper is titled “An Ultra-Thin Invisibility Skin Cloak for Visible Light.” Xingjie Ni and Zi Jing Wong are the lead authors. Other co-authors are Michael Mrejen and Yuan Wang.