Summary: A novel technique for the in situ calibration and measurement of friction
with the atomic force microscope
Johanna Stiernstedt and Mark W. Rutland
Department of Chemistry, Surface Chemistry, Royal Institute of Technology, SE-100 44 Stockholm, Sweden
and Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden
School of Chemistry F11, University of Sydney, Sydney NSW 2006, Australia
Received 26 April 2005; accepted 30 June 2005; published online 5 August 2005
Presented here is a novel technique for the in situ calibration and measurement of friction with the
atomic force microscope that can be applied simultaneously with the normal force measurement.
The method exploits the fact that the cantilever sits at an angle of about 10° to the horizontal, which
causes the tip or probe to slide horizontally over the substrate as a normal force run is performed.
This sliding gives rise to an axial friction force in the axial direction of the cantilever , which is
measured through the difference in the constant compliance slopes of the inward and outward traces.
Traditionally, friction is measured through lateral scanning of the substrate, which is time
consuming, and requires an ex situ calibration of both the torsional spring constant and the lateral
sensitivity of the photodiode detector. The present method requires no calibration other than the
normal spring constant and the vertical sensitivity of the detector, which is routinely done in the
force analysis. The present protocol can also be applied to preexisting force curves, and, in addition,
it provides the means to correct force data for cantilevers with large probes. © 2005 American