A lack of understanding of the fundamental mechanisms governing atomic-scale adhesion and friction creates ongoing challenges as technologically-relevant devices are miniaturized. One major class of failure mechanisms of such devices results from high friction, adhesion, and wear. This thesis presents investigations into methods by which atomic-scale friction and adhesion can be controlled. Using atomic force microscopy (AFM), friction and adhesion properties of graphene were examined. While friction between the tip and graphene depends on thickness, as explained by the "puckering effect", adhesion is independent of the thickness when measured conventionally. However, adhesion is transiently higher when measured after the tip has slid over the graphene. This effect is caused by increased adhesiveness between graphene and tip due to aging. Second, chemical modification of graphene, specifically fluorination, affects friction strongly, with friction monotonically increases with increasing degree of fluorination. As supported by molecular dynamics (MD) simulations, this dependence is attributed to the fact that attachment of fluorine to graphene greatly enhances the local energy barrier for sliding, thereby significantly altering the energy landscape experienced by the tip. Finally, through matched AFM and MD, the speed dependence of atomic friction was explored within the framework of the Prandtl-Tomlinson model with thermal activation (PTT). For the first time, experiments and simulations are performed at overlapping scanning speeds. While friction was found to increase with the log of speed in both AFM and MD, consistent with the PTT model, friction in experiments was larger than in MD. Analysis revealed that the discrepancy was largely attributable to the differences in contact area and tip masses used in experiments vs. in simulation. Accounting for the overall influence of the two with the presence of instrument noise fully resolves the discrepancy. Through those novel studies and findings, it has been demonstrated that atomic-scale friction and adhesion can be controlled and understood, assisting the development of applications where variable or constant friction and adhesion are desired.

Friction, lubrication, adhesion, and wear are prevalent physical phenomena in everyday life and in many key technologies. This book explains how these tribological phenomena originate from atomistic and microscale physical phenomena and shows how this understanding can be used to solve macroscale tribology problems.

Solid Lubrication Fundamentals and Applications description of the adhesion, friction, abrasion, and wear behavior of solid film lubricants and related tribological materials, including diamond and diamond-like solid films. The book details the properties of solid surfaces, clean surfaces, and contaminated surfaces as well as discussing the structu

Written by one of the most distinguished scientists and a pioneer in this field, this monograph represents a stand-alone, concise guide to friction at the atomic level. It brings together hitherto widely-scattered information in one single source, and is the first to explain the nature of friction in terms of atomistic mechanisms. In addition to his detailed description on modeling and simulation, the author stresses experimental approaches like AFM (Atomic Force Microscope) techniques for verification of theory. In this respect the book will benefit the whole nanotribology community, from graduate students who want to get the basics right up to researchers specializing in mechanical engineering, materials science, physics and chemistry.

Fundamentals of Friction, unlike many books on tribology, is devoted to one specific topic: friction. After introductory chapters on scientific and engineering perspectives, the next section contains the necessary background within the areas of contact mechanics, surfaces and adhesion. Then on to fracture, deformation and interface shear, from the macroscopic behavior of materials in frictional contact to microscopic models of uniform and granular interfaces. Lubrication by solids, liquids and gases is presented next, from classical flow properties to the reorganization of monolayers of molecules under normal and shear stresses. A section on new approaches at the nano- and atomic scales covers the physics and chemistry of interfaces, an array of visually exciting simulations, using molecular dynamics, of solids and liquids in sliding contact, and related AFM/STM studies. Following a section on machines and measurements, the final chapter discusses future issues in friction.

Readers of this book will become familiar with the concepts and techniques of nanotribology, explained by an international team of scientists and engineers, actively involved and with long experience in this field. Edited by two pioneers in the field, the book is suitable both as a first introduction to this fascinating subject, and also as a reference for researchers wishing to improve their knowledge of nanotribology.

This application-oriented book introduces readers to the associations and relationships between contact mechanics and friction, providing them with a deeper understanding of tribology. It addresses the related phenomena of contacts, adhesion, capillary forces, friction, lubrication, and wear from a consistent point of view. The author presents (1) methods for rough estimates of tribological quantities, (2) simple and general methods for analytical calculations, and (3) the crossover into numerical simulation methods, the goal being to convey a consistent view of tribological processes at various scales of magnitude (from nanotribology to earthquake research). The book also explores the system dynamic aspects of tribological systems, such as squeal and its suppression, as well as other types of instabilities and spatial patterns. It includes problems and worked-out solutions for the respective chapters, giving readers ample opportunity to apply the theory to practical situations and to deepen their understanding of the material discussed. The second edition has been extended with a more detailed exposition of elastohydrodynamic lubrication, an updated chapter on numerical simulation methods in contact mechanics, a new section on fretting in the chapter on wear, as well as numerous new exercises and examples, which help to make the book an excellent reference guide.