Hooke's law and fatigue limits in micromechanics.

Scanning tunnelling microscopes can be used to detect transitions between reversible and irreversible deformations of materials. Since the occurrence of stress-strain hysteresis is a necessary condition for the generation of material defects, and the cumulation of defects is, in turn, the underlying cause of fatigue failure, the observation of non-hysteretic reversible deformations extending over many atomic lengths implies that mechanical nanoscale devices are potentially capable of having service lives of extremely long duration.