Mechanism of wear and ripple formation induced by the mechanical action of an atomic force microscope tip

We propose a model for a description of formation of quasiperiodic nanoscale patterns induced by scratching a surface with an atomic force microscope tip. The simulations demonstrate that the interplay between the developing surface corrugation and the frictional stress produced by the moving tip plays a decisive role in the formation of the regular ripples. Our model reveals the size and shape of the tip as the main factors that determine periodicity and amplitudes of the patterns, and it allows experimental observations to be explained. It is shown that the wear at the nanoscale cannot be explained by conventional macroscopic wear theories.