Departmental Papers (MEAM)

Document Type

Journal Article

Date of this Version

February 1999


Copyright (1999) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. Reprinted in Physical Review Letters, Volume 82, Issue 6, February 1999, pages 1181-1183.

NOTE: At the time of publication, author Robert W. Carpick was affiliated with the University of Wisconsin. Currently (June 2007), he is a faculty member in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania. Publisher URL:


Recent molecular level studies of energy dissipation in sliding friction have suggested a contribution from adhesive forces. In order to observe this directly, we have constructed a scanning force microscope with decoupled lateral and normal force sensors to simultaneously observe the onset of both friction and attractive forces. Measurements made on self-assembling alkanethiol films with chemically different tail groups show that friction can increase with stronger adhesive intermolecular forces and from the associated tensile deformation and collective motion of the thiol chains.



Date Posted: 25 June 2007

This document has been peer reviewed.