Vanishing friction
Friction is all around us, working against the motion of tires on pavement, the scrawl of a pen across paper, and even the flow of proteins through the bloodstream. Whenever two surfaces come in contact, there is friction, except in very special cases where friction essentially vanishes — a phenomenon, known as “superlubricity,” in which surfaces simply slide over each other without resistance. Now physicists at MIT have developed an experimental technique to simulate friction at the nanoscale. Using their technique, the researchers are able to directly observe individual atoms at the interface of two surfaces and manipulate their arrangement, tuning the amount of friction between the surfaces. By changing the spacing of atoms on one surface, they observed a point at which friction disappears. Vladan Vuletic, the Lester Wolfe Professor of Physics at MIT, says the ability to tune friction would be helpful in developing nanomachines — tiny robots built from...