The rules that govern these interactions in natural materials can be circumvented in metamaterials whose optical properties arise from their physical structure rather than their chemical composition. It is the scattering of light - be it visible, infrared, X-ray, etc., - from its interaction with matter that enables us to detect and observe objects. Other co-authors are Michael Mrejen and Yuan Wang. The paper is titled "An Ultra-Thin Invisibility Skin Cloak for Visible Light." Xingjie Ni and Zi Jing Wong are the lead authors. 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. It is easy to design and implement, and is potentially scalable for hiding macroscopic objects." "Our ultra-thin cloak now looks like a coat. "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. 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. 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. 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. 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. 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. view moreĬredit: Image courtesy of Xiang Zhang group, Berkeley Lab/UC Berkeley Light reflects off the cloak (red arrows) as if it were reflecting off a flat mirror. How about fashion design? Ni suggested a cloak that "can be made to hide one's belly.Image: This image shows a 3-D illustration of a metasurface skin cloak made from an ultrathin layer of nanoantennas (gold blocks) covering an arbitrarily shaped object. How about a cloaking mask for the face? "All the pimples and wrinkles will no longer be visible," Ni said. Ni also mentioned some unconventional applications. Ni said the technology eventually could be used for military applications like making large objects like vehicles or aircraft or even individual soldiers "invisible." The researchers said they overcame two drawbacks of previous experimental microscopic cloaks that were bulkier and harder to "scale up," or become usable for larger objects. We also can make a flat surface appear curved," said Penn State University electrical engineering professor Xingjie Ni, the study's lead author. "The fact that we can make a curved surface appear flat also means that we can make it look like anything else. The cloaking "skin" boasts microscopic light-scattering antennae that make light bouncing off an object look as if it were reflected by a flat mirror, rendering the object invisible. They redirect incoming light waves, shifting them away from the object being cloaked. Their surfaces bear features much smaller than the size of a wavelength of light. The technology involves so-called metamaterials, which possess properties not present in nature. But much more work needs to be done," said Zhang, whose research was published in the journal Science. It may take five to 10 years to make the technology practical to use, according to Xiang Zhang, director of the Materials Sciences Division of the US Department of Energy's Lawrence Berkeley National Laboratory and a professor at the University of California, Berkeley.
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