title: Reinterpretation of velocity-dependent atomic friction: influence of the inherent instrumental noise in friction force microscopes.
abstract: We have applied both the master equation method and harmonic transition state theory to interpret the velocity-dependent friction behavior observed in atomic friction experiments. To understand the discrepancy between attempt frequencies measured in atomic force microscopy experiments and those estimated by theoretical models, both thermal noise and instrumental noise are introduced into the model. It is found that the experimentally observed low attempt frequency and the transition point at low velocity regimes can be interpreted in terms of the instrumental noise inherent in atomic force microscopy. In contrast to previous models, this model also predicts (1) the existence of a two-slope curve of velocity dependence and (2) the decrease of critical velocity with temperature, which provides clues for further experimental verification of the influence of instrumental noise in friction measurements.
authors.affiliation: Department of Mechanical Engineering, University of Akron, 302 Buchtel Common, Akron, Ohio 44325, USA.
authors.forename: Yalin
authors.initials: Y
authors.lastname: Dong
authors.affiliation: School of Engineering, University of California Merced, 5200 North Lake Road, Merced, California 95343, USA.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Gao
authors.affiliation: School of Engineering, University of California Merced, 5200 North Lake Road, Merced, California 95343, USA.
authors.forename: Ashlie
authors.initials: A
authors.lastname: Martini
authors.affiliation: Department of Mechanical and Manufacturing Engineering, University of Calgary, 40 Research Place NW, Calgary, Alberta T2L 1Y6, Canada.
authors.forename: Philip
authors.initials: P
authors.lastname: Egberts
mesh_terms: D016477:Artifacts; D017276:Friction; D018625:Microscopy, Atomic Force / Q000295:instrumentation*; D008962:Models, Theoretical; D013696:Temperature