The smallest brush in the world has been invented at the Rensselaer Polytechnic Institute in New York. The crines of the nanobrush are carbon nanotubes of 30 billion meters in diameter. To move the bristles from the handle to the head, it has a gold cap. Although it is very small, it is very hard, but also flexible. In addition, like other brushes, it serves many things: to clean the nanofibor, to paint nanostructures... He is able to transport electricity and believes it can also be useful in medicine.