New technique for studying nanoscale friction at sliding velocities up to 200mm∕s using atomic force microscope

Micro-/nanoelectromechanical devices and components operate at high sliding velocities. Studies of tribological properties of materials by atomic force microscope (AFM) are limited to low velocity regime (<100–250μm∕s) due to inherent instrument limitation of AFM. To overcome the limitation of AFM working velocity, a custom-calibrated ultrahigh velocity stage has been incorporated for tribological investigation up to 200mm∕s. The stage is driven by a piezoactuator which is controlled using proportional-integral-derivative algorithm. Friction data are obtained by processing the AFM laser photodiode signals using a high sampling rate data acquisition system. The friction data obtained from the modified setup at high sliding velocities are compared with the results from conventional AFM friction measurement. The effects of scan size, rest time, and velocity on the friction force and adhesive force for single crystal silicon (100) with native oxide have been studied.