Molecular bearing. Computer graphic of a molecular bearing, a frictionless bearing designed and built by computer simulation as part of nanotechnology research. Each of the coloured spheres represents a single atom. If made for real, the bearing would be too small to see even with the world's most powerful microscope. Nanotechnology is one of the frontiers of science. It involves the construction of machines and circuits little bigger than molecules, and could one day lead to a host of revolutionary miniature inventions, such as microscopic nanorobots" that patrol the human body in search of cancer tumours."