Now two physicists in the USA have identified what could be the perfect swivel joints for microscopic devices with moving parts. This could be used as a swivel joint or a free-sliding telescopic arm in nanoscale engineering. Automated machines this tiny could be used in medicine, information technology or 'smart' materials.
Life is different in the nanoworld.
And Kolmogorov and Crespi have revealed something totally unexpected in the behaviour of a nanoscale bearing. They say that the sliding of a tiny tube of pure carbon within a tubular sleeve of the same material is nearly frictionless, no matter how long the tubes are. And carbon nanotubes typically form as many nested cylinders, one inside another like Russian dolls. So potentially, they represent ready-made nanoscale bearings, in which one tube could rotate or telescope within another. But their properties depend in a very subtle way on how the carbon atoms are arranged in the walls.