SPMW Mechanisms of atomic friction studied by friction force microscopy
12 Dec 2006 | Online Presentations | Contributor(s): Ernst Meyer
Force microscopy is a versatile instrument to investigate physical phenomena on surfaces. The first emphasis is on the study of friction on the nanometer-scale, also called nanotribology. It will be shown that atomic-scale stick-slip is relatively well understood, where the dependence on velocity and normal force is experimentally investigated and interpreted in terms of an extended Tomlinson model. It is essential to include thermal actuation to understand the observed phenomena. The transition from atomic-scale stick slip to continuous sliding will be described . The detailed analysis yields the energy corrugation and the lateral contact stiffness as a function of load. It is found that continuum mechanics is not anymore valid at these dimensions. Recently, it has been shown that atomic friction can be controlled with rather high accuracy by electrostatic actuation . In the second part the phenomenon non-contact friction is studied by ultra-sensitive cantilevers in the pendulum geometry, where forces in the atto-newton regime are accessible .