Dynamic superlubricity and the elimination of wear on the nanoscale

One approach to ultrahigh-density data storage involves the use of arrays of atomic force microscope probes to read and write data on a thin polymer film, but damage to the ultrasharp silicon probe tips caused by mechanical wear has proved problematic. Here, we demonstrate the effective elimination of wear on a tip sliding on a polymer surface over a distance of 750 m by modulating the force acting on the tip-sample contact. Friction measurements as a function of modulation frequency and amplitude indicate that a reduction of friction is responsible for the reduction in wear to below our detection limit. In addition to its relevance to data storage, this approach could also reduce wear in micro- and nanoelectromechanical systems and other applications of scanning probe microscopes.