Nanotribology, nanomechanics and materials characterization

Abstract

Nanotribology and nanomechanics studies are needed to develop a fundamental understanding of interfacial phenomena on a small scale, and to study interfacial phenomena in micro/nanoelectromechanical systems (MEMSmicroelectromechanical system (MEMS)/NEMSnanoelectromechanical system (NEMS)), magnetic storage devices, and many other applications. Friction and wear of lightly loaded micro/nanocomponents are highly dependent on surface interactions (a few atomic layers). These structures are generally coated with molecularly thin films. Nanotribology and nanomechanics studies are also valuable in the fundamental understanding of interfacial phenomena in macrostructures, and provide a bridge between science and engineering. An atomic force microscope (AFMatomic force microscopy (AFM)) tip is used to simulate a single-asperity contact with a solid or lubricated surface. AFMs are used to study the various tribological phenomena, which include surface roughness, adhesion, friction, scratching, wear, detection of material transfer, and boundary lubrication. In situ surface characterization of local deformation of materials and thin coatings can be carried out using a tensile stage inside an AFM. Mechanical properties such as hardness, Young's modulus of elasticity, and creep/relaxation behavior can be determined on micro- to picoscales using a depth-sensing indentation system in an AFM. Localized surface elasticity and viscoelastic mapping near surface regions can be obtained with nanoscale lateral resolution. Finally, an AFM can be used for nanofabrication/nanomachining.