AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Monday Sessions
       Session NS+SS-MoM

Paper NS+SS-MoM6
Friction and Adhesion in the Attractive Regime

Monday, November 2, 1998, 10:00 am, Room 321/322/323

Session: Tribology, Adhesion and Interfacial Forces
Presenter: A.R. Burns, Sandia National Laboratories
Authors: A.R. Burns, Sandia National Laboratories
J.E. Houston, Sandia National Laboratories
R.W. Carpick, Sandia National Laboratories
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Recent molecular level measurements and simulations have shown a strong connection between adhesive bonding forces and energy dissipation in sliding friction. In order to observe this directly, we have constructed a scanning force microscope with de-coupled lateral and normal force sensors to simultaneously observe the onset of both friction and chemical bond formation. Furthermore, by using a mechanically-stable interfacial force sensor,@footnote 1@ we are able to map the entire attractive interaction between the probe tip and the sample surface. Measurements made on self-assembling alkanethiol films with chemically different head groups show that friction can be directly attributed to bond formation and rupture well before repulsive contact. Thus we are able to separate chemical friction from more traditional mechanical sources of energy dissipation.@footnote 2@ @FootnoteText@ @footnote 1@ S. A. Joyce and J. E. Houston, Rev. Sci. Instrum. 62, 710 (1991). @footnote 2@ Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.