ATOMIC-SCALE FRICTION MEASUREMENTS USING FRICTION FORCE MICROSCOPY .1. GENERAL-PRINCIPLES AND NEW MEASUREMENT TECHNIQUES

Friction force measurements using modified atomic force microscopy, called here Friction Force Microscopy (FFM), are becoming increasingly important in the understanding of fundamental mechanisms of friction, wear, and lubrication, and to study interfacial phenomena in micro- and nanostructures used in magnetic storage systems and Microelectromechanical Systems (MEMS). FFMs can be used to study engineering surfaces in dry or wet conditions. A review of existing designs of FFMs and methods of friction force measurements is presented. In terms of friction force measurements, there are important issues related to the basic operation and calibration of these instruments which have not been fully studied. A new method of measuring friction fore using a commercial FFM and a calibration procedure for con version of measured data to normal and friction forces are presented. Micro-scale friction data of selected materials are presented and discussed in light of macro-friction measurements.