Nanotribology and Lubrication at Nanoscale: Molecular Dynamics Simulation Studies

A. Jabbarzadeh
The University of Sydney, AU

Keywords: molecular dynamics simulations, nanotribology, low friction, adhesion, surface modifications, gold, SAMs, self assembled monolayers

Summary:

Increasing technological advances to make devices and processes at the nanoscale, have made it necessary to effectively minimize the friction and adhesion of moving mechanical assemblies, such as those in micro- or nano-electromechanical (MEMS/NEMS) devices. Lubrication and frictional properties of such systems are complex and often do not obey established laws of macroscale lubrication and friction. Two aspects of the problem are extremely important, for such systems. How the properties of the surfaces and the type of the lubricant affect the lubrication and interaction of the contacting surfaces. In this work, the results of large scale molecular dynamics simulations will be presented to demonstrate, how the properties of confined lubricant can be affected and controlled by manipulating the structure, roughness, and type of the substrate. Two types of lubricants, including freely moving molecules and self assembled monolayers will be described in this work. It will be shown by simply manipulating the characteristics of the contacting surfaces, one can change the rheological state of the film and as a result the tribological properties of the contact. Self assembled monolayers (SAMs) will be shown to have diverse mechanical, tribological and thermal properties, and should be employed by understating such considerations.