Scientists have devised an invisibility cloak material that can hide objects from the human eye. Xiang Zhang and colleagues note that invisibility cloaks, which route electromagnetic waves around an object to make it undetectable, 'are still in their infancy'.Most cloaks are made of materials that can only hide things using microwave or infrared waves, which are just below the threshold of human vision.
To remedy this, the researchers built a reflective 'carpet cloak' out of layers of silicon oxide and silicon nitride etched in a special pattern.
The carpet cloak works by concealing an object under the layers, and bending light waves away from the bump that the object makes, so that the cloak appears flat and smooth like a normal mirror.
Although the study cloaked a microscopic object roughly the diameter of a red blood cell, the device demonstrates that it may be capable of cloaking any object underneath a reflective carpet layer.