World's smallest toothbrush scrubs capillaries clean - small electric toothbrush

Duncan GrahamRoweNano-
Researchers have developed large and small toothbrushes that can clean very small surfaces.
These tiny brushes are made of millions of carbon nanotubes and can even paint the inside of the capillary tube thinner than human hair.
But, in addition to being small, the nanotubes have other advantages over traditional bristles, says Pulickel Ajayan, a creator of New York's Troy rensler Institute of Technology.
Materials commonly used to make bristles include animal hair, synthetic polymer fibers, and metal wires.
But each has its limitations.
The metal is corroded and weakened, the hair is not very strong, the synthetic fiber will melt.
On the other hand, carbon nanotubes are 30 times stronger than steel, but the density is 5 times lower.
They have high elasticity, heat resistance, large surface area and can even conduct electricity.
The latter feature makes them ideal for contact brushes for electric motors, Ajayan said.
He and his colleague from the University of Hawaii in Honolulu, USA, at Anyuan Cao in rensler, I designed a brush consisting of a sic fiber base, on which, carbon nanotubes grow in a row of bristles like toothbrushes, or more like toilet brushes.
The end of the bottom is coated with gold, which acts like a "handle" and also inhibits the growth of the nanotubes at that end.
There may be a big change in size, Ajayan said, but normally the diameter of the nanotube bundle will not be less than a few microns.
Brushes can be used in a variety of applications.
They have been used to scan particles with a diameter of only 50 nm, from a flat surface, from another surface, with a micro groove pit.
The researchers also attached a three-
There is a brush head on the shaft of the small motor.
This allows them to be at 300-micrometre-
Wide capillary, clean the pollution on the wall.
Then, by coating the brush with a red dye, they were able to draw the inside of the cavity using the same method.
Ajayan says the ability to clean the particles in the bush seems very good, although he still doesn't know why.
"Maybe cleaning is done by electrostatic interaction, and cleaning may be more effective due to the large surface area of the nano-structure.
"The goal now is to apply brushes to more specific electronic and biomedical applications.
Magazine reference and colon;
Natural materials (DOI: 10. 1038/nmat1415)