A few years after the invention of the scanning tunneling microscope (STM), the atomic force microscope (AFM) was developed Instead of measuring tunneling current, a new physical quantity could be investigated with atomic-scale resolution: the force between a small tip and a chosen sample surface This paper reviews progress and recent results obtained with AFM and other closely related techniques in the field of nanotribology, and attempts to point out many of the unresolved questions that remain The goal of this paper is to demonstrate that AFM is capable of producing atomic-scale knowledge As such, the authors will focus upon some of the contributions of the AFM to nanotribology They will almost exclusively discuss results that shed light on the actual atomic and molecular processes taking place, as opposed to the more applied investigations of microscale properties which are also carried out with AFM They will accompany this discussion by mentioning related theoretical efforts and simulations, although their main emphasis will be upon experimental results and the techniques used to obtain them, as well as suggested future directions In many ways, AFM techniques for quantitative, fundamental nanotribology are only in a nascent stage; certain key issues such as force calibration,more » tip characterization, and the effects of the experimental environment, are not fully resolved or standardized The authors thus begin with a critical discussion of the relevant technical aspects with using AFM for nanotribology 289 refs« less

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Scratching the Surface: Fundamental Investigations of Tribology with Atomic Force Microscopy.

Part I: Base Oils 1 Base oils from petroleum R.J. Prince 2 Synthetic base fluids M. Brown, J.D. Fotheringham, T.J. Hoyes, R.M. Mortier, S.T. Orszulik, S.J. Randles and P.M. Stroud Part II: Additives 3 Friction, wear and the role of additives in controlling them C.H. Bovington 4 Oxidative degradation and stabilisation of mineral oil based lubricants G. Aguilar, G. Mazzamaro and M. Rasberger 5 Viscosity index improvers and thickeners R.L. Stambaugh and B.G. Kinker 6 Miscellaneous additives and vegetable oils J. Crawford, A. Psaila and S.T. Orszulik 7 Detergents and Dispersants E.J. Seddon, C.L. Friend and J.P. Roski Part III: Applications 8 Industrial lubricants C. Kajdas, A. Karpinska, and A. Kulczycki 9 Formulation of Automotive Lubricants D. Atkinson, A.J. Brown and G. Lamb 10 Driveline Fundamentals and Lubrication I. Joseph 11Aviation Lubricants A.R. Lansdown and S. Lee 12 Liquid Lubricants for Spacecraft Applications S. Gill and A. Rowntree 13 Marine lubricants B.H. Carter and D. Green 14 Lubricating Grease G. Gow Part IV: Performance 15 Lubricants and their environmental impact C.I. Betton 16 Oil Analysis and Condition Monitoring A. Toms and L. Toms 17 Automotive Lubricant Specification and Testing M.F. Fox

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Chemistry and Technology of Lubricants

Automotive tribology overview of current advances and challenges for the future

A simple theory of asperity contact in elastohydro-dynamic lubrication

The in vivo friction of human skin has been measured in the dry, wet and damp states using smooth glass and polypropylene spherically tipped probes. They were selected to be representative of hydrophilic and hydrophobic countersurfaces. The data are interpreted using the adhesion model of friction, which provides an explanation for the influence of the normal load and the surface free energies of the probe materials on the frictional characteristics of the skin. In particular, explanations based on this model are given for the tendency of wet skin to exhibit stick-slip motion and of damp skin to exhibit a peak frictional force against a glass probe.

Friction and lubrication of human skin

This paper presents a solution to the problem of hydrodynamic lubrication of highly loaded clastic cylinders under isothermal conditions. A numerical method is developed which enables a pressure cu...

A Numerical Solution to the Elasto-Hydrodynamic Problem

Elasto-hydrodynamic lubrication

Recent work by the authors and others on the lubrication of elastic rollers is briefly reviewed. The full effects of speed over a wide range and of lubricant compressibility are presented for the f...

Elasto-Hydrodynamic Lubrication: A Survey of Isothermal Solutions

The effect of the significant variables on solutions to the problem of isothermal lubrication of elastic rollers is examined It is found that for realistic materials, speeds, and loads, the outlet pressure peak predicted by Grubin (4) is always present The magnitude of this pressure peak may exceed the maximum Hertzian pressure It varies only slightly with load, but markedly with speed and materials The influence of these variables on the shape of the outlet pressure curve explains the difference between Petrusevich's results (5) and those presented earlier by the authors The stress concentrations produced near the surface by the outlet pressure peak would have a significant effect on the fatigue life of rolling elementsIt is found that the centre-line film thickness varies hardly at all with load, significantly with material properties and considerably with the product of speed and inlet viscosityPressure distributions and film shapes are presented for five cases to illustrate the influence of loa

The Effect of Material Properties on the Lubrication of Elastic Rollers

It is almost fifty years since theoretical work on elastohydrodynamic lubrication commenced in the Department of Mechanical Engineering of The University of Leeds. Details of the development of numerical solutions to the line contact problem during the six year period (1956–1962) that the authors worked together on the problem will be outlined. The computing aids available during the eighteen month period involved in generating the first solution consisted of two hand operated mechanical calculating machines, with the first digital computer at Leeds being installed in 1959. The general research environment during the period will be recalled and a number of significant events recorded. It is appropriate to record at this Symposium aspects of these initial developments in a subject which has dominated research in tribology throughout the latter part of the 20th and into the early years of the 21st centuries. The excitement of being involved in taking some of the first steps in a field described by the late Professor F.T. Barwell (1970) as “the major event in the development of lubrication science since Reynolds’s own paper”, will be recalled.

G. R. Higginson

Papers

A Numerical Solution to the Elasto-Hydrodynamic Problem

Elasto-hydrodynamic lubrication

Elasto-Hydrodynamic Lubrication: A Survey of Isothermal Solutions

The Effect of Material Properties on the Lubrication of Elastic Rollers

Reflections on Early Studies of Elasto-Hydrodynamic Lubrication