Study of interfacial friction mechanism based on the coupled-oscillator model

A new coupled-oscillator model, in which the relationship of the lateral force and the normal force are considered, is proposed for the interfacial friction. The Maugis-Dugdal model is used to approximately substitute the Lennard-Jones potential of the interfacial friction in the new model. The mechanism of microscopic sliding and the energy dissipation mechanism of friction are discussed. The formulae for frictional force calculation are then deduced. Based on theoretical analysis, it is found that the frictional force increases approximately as 2/3 the power of the normal force for a tip-sample contact system, which is same as the classical conclusion of nano-tribology. A comparison between the theoretical results and the experimental data obtained with an atomic force microscope is presented at the end of the paper. The result has shown that the new coupled-oscillator model and the formulae deduced are feasible.