Multiscale friction mechanisms and hierarchical surfaces in nano- and bio-tribology

Various mechanisms of solid–solid and solid–liquid friction are studied in this review, and their relation to the surface roughness hierarchy is discussed. For ideal solid bodies with conservative forces acting between them, there would be no friction. Different deviations from the ideal state, such as the surface roughness, contamination and chemical heterogeneity, bulk material deformation and non-conservative adhesive bonds, lead to energy...