This news release is available in Japanese.
Researchers have made a small object disappear using an ultra-thin invisibility cloak, a new study reports. While the cloak has limitations, and is far from practical applications, it is much less bulky and more akin to a skin than previous designs. In recent years, scientists have continued to chip away at advances to the invisibility cloak concept; however, existing designs have substantial limitations that render them unwieldy, unadaptable to different environments, or limited to cloaking only very tiny (microscopic) objects. Development of metamaterials -- those engineered to have properties not yet found in nature -- has opened up doors to progress; because the surfaces of these materials have features smaller in size than a wavelength of light, they can reroute incoming light waves, steering them around or away from an object, the road to making it "invisible." Here, by carefully tailoring a reflective metasurface with small, light-scattering antennae that ensured the intensity of light scattered from the metasurface was close to that of light scattered from a flat mirror, Xingjie Ni and colleagues showed they could render a small object - 36 micrometers by 36 micrometers - undetectable. Because of the way their cloak was designed, they say, it could even conceal objects with sharp edges and peaks, a feat historically challenging for invisibility cloak efforts. And unlike other attempts at an invisibility cloak, this new design is also scalable, the authors say.
Article #10: "An ultrathin invisibility skin cloak for visible light," by X. Ni; Z.J. Wong; M. Mrejen; Y. Wang; X. Zhang at University of California, Berkeley in Berkeley, CA; Y. Wang; X. Zhang at Lawrence Berkeley National Laboratory in Berkeley, CA.