Calibration of atomic force microscope for nanoscale friction measurements

Friction force measurements provide with important information for application in which moving objects are in physical contact. Mechanisms of friction, adhesion, lubrication and wear are crucial issues in case of highly advanced micro-electro-mechanical systems (MEMS) or high-density data storage devices, where minimized friction forces are required. Studies of those phenomena in nanoscale can be successfully carried out by means of an atomic force microscope using optical beam deflection sensing. However, to obtain quantitative information the calibration procedure for conversion of measured data to friction forces has to be applied. In order to calibrate our atomic force microscope we applied direct procedure called wedge calibration method. The results of friction force calibration using commercially available grating are presented in this paper. We depict experimental results for nanotribology on two different crystallographic planes of silicon, mica and highly oriented pyrolytic graphite (HOPG) as well.