Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
School of Chemistry F11, University of Sydney, NSW 2006 Australia.
Rev. Sci. Instrum. 69 , 3852-3866 (1998).
Abstract
Theoretical calculations and experimental measurements are used to show
that hitherto neglected inertial effects can be significant
in computer-controlled surface force measurement devices
such as the atomic force microscope.
The problem is analysed in detail for the case of the
van der Waals attraction in air.
It is demonstrated that equating the cantilever deflection
to the surface force systematically underestimates
the magnitude of the surface force,
increasingly so as the speed of approach is increased.
It is also shown that the surface separation
becomes lost at high accelerations due to a
dynamic uncoupling of the cantilever deflection and angle.
The effects of elastic deformation of the bodies are taken into account,
including the collision-induced elastic vibrations in the solids.
Experimental data is obtained for the van der Waals attraction
and collision of glass surfaces in air using
the MASIF force measurement device.
All of the effects found in the theoretical calculations
are identified in the experimental data.
Back to publications or to Phil Attard's home page.