United States. A carbon nanotube coating developed at the University of Michigan acts as a "black magic cloth" that hides an object of three-dimensional geometry and makes it look like a flat sheet.
The researchers say that the 70-micron coating or carbon nanotube carpet is about half the thickness of a sheet of paper. It absorbs 99.9% of the light that hits it.
"You can use it to completely hide the 3D attributes of an object. It is not the cover-up, the object can still cast a shadow. But if you put an object on a black background, and then with this coating, it could become invisible," said Jay Guo, a professor in the department of electrical engineering and a senior researcher in computer science.
To demonstrate this concept, the researchers made an approach, a shape of the microscopic tank in a piece of silicon. Then the carpet of carbon nanotubes grew on top of the silicon chip. Photos taken through an optical microscope show that the tank is imperceptible. As a control, they did it again, forging a rectangle that was not covered with carbon nanotubes. The rectangle is visible on this chip, but the tank remains hidden.
The coating works as follows: the human eye perceives an object based on the way it reflects and scatters light. The "refractive index" of this new layer is similar to that of air, that is, light travels through the air and is not scattered or reflected when it hits the coating.
"The carbon nanotube can absorb a variety of electromagnetic waves from ultraviolet rays to terahertz," Guo added.
Leave your comment