Origins of friction

Cieplak M, Smith E D and Robbins M O 1994 Molecular origins of friction the force on adsorbed layers Science 256 1209... 

Finally, it deserves to be mentioned that considerable numbers of models of static friction based on continuum mechanics and asperity contact were proposed in the literature. For instance, the friction at individual asperity was calculated, and the total force of friction was then obtained through a statistical sum-up [35]. In the majority of such models, however, the friction on individual asperity was estimated in terms of a phenomenal shear stress without involving the origin of friction. 

Atomic-Scale Origin of Friction between Diamond (111) Surfaces. 

Neitola, R. Pakkanen, T. A. Ab Initio Studies on the Atomic-Scale Origin of Friction between Diamond (Iff) Surfaces./. Phys. Chem. B 2001, 105, 1338-1343. 

The last term is the rate of viscous energy dissipation to internal energy, Ev = jv <5 dV, also called the rate of viscous losses. These losses are the origin of frictional pressure drop in fluid flow. Whitaker and Bird, Stewart, and Lightfoot provide expressions for the dissipation function <5 for Newtonian fluids in terms of the local velocity gradients. However, when using macroscopic balance equations the local velocity field within the control volume is usually unknown. For such... 

Goodyear G, Larsen RE, Stratt RM. Molecular origin of friction in liquids. Phys Rev Lett 1996 76 243-246. 

J. ICrim, Atomic-scale Origins of Friction, Langmuir 19 (1996) 4654-4656. 

The origin of friction is the adhesion between the tips of the asperities of two materials opposite each other, and if one surface is harder than the other, also ploughing of grooves by the harder material. 

Krim, J. Surface science and the atomic-scale origins of friction what once was old is new again. Surf. Sci. 2002, 500, 741-758. 

Goodyear G, Larsen R E and Stratt R M 1996 Molecular origin of friction in liquids Phys. Rev. Lett. 76 243-6... 

Bowden and Tabor have presented strong evidence in order to establish that the adhesive origin of friction on dry surfaces accounts for a major share of the total resistance offered to sliding. Despite this, misgivings have often been spelt, since no so-called "force of adhesion" is noticeable during normal separation o f bodies in contact under ordinary conditions. Regarding the implication of our understanding of matter, it would seem only natural that the molecules within the real area of contact adhere. 

The concept of adhesion as a constraint to relative motion enables to clarify misgivings regarding the adhesive origin of friction. 

The technique of friction force microscopy has been refined and the nanoscopic and atomic origins of friction have been explored in detail this has developed... 

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