Micro and Nanotribology
1 Introduction to Micro and Nanotribology
In Jinkoki published in 1627, the terms micro and nano are defined as (bi) and (jin) in Japanese, both of which mean very tiny quantities down to 10−6m∼10−9m. This does not mean that the micro and nanotribology is the dust science of tribology. Micro and nanotribology studies the intrinsic processes of physical, chemical and mechanical phenomena occurring at the surfaces and interfaces.
The tribological aspects determined by size are widely spread. Wear depth, for example, pertains to the unit of daily life, fluid film thickness in hydrodynamic lubrication is in micrometer units, the atomic manipulation treats an individual atom and tribo-reacted surface film is atomically thin, either of these being in sub-nanometer units. Sometimes, the tribology of miniature machines, i.e., micromachines (MEMS), nanomachines (NEMS), magnetic recording systems for the next generation, etc., is referred to as micro and nanotribology. It is true that tribology of tiny machines is included in micro and nanotribology, but this may be a narrow definition of micro and nanotribology.
The physical/chemical interactions take place at the contacting spots during tribological processes. These interaction processes together with the reaction products at the surface and interface determine friction, lubrication and wear. The macroscopic outputs such as friction coefficient and wear volume are the summarization of microscopic, or even of nanoscaled, outputs. Therefore, the goal of micro and nanotribology is to identify surface and interface phenomena from an atomic and molecular level , .