ADHESION FORCES BETWEEN SURFACE-MODIFIED AFM TIPS AND A MICA SURFACE

The adhesion force between modified AFM tips and a mica substrate has been studied using an atomic force microscope. The force-distance curv es measured by the microscope show that the adhesion force is sensitiv e to the surface energies of the materials coated on the tips. The adh esion force between a gold-coated tip and a mica surface is much large r than that between a paraffin-coated tip and a mica surface. A simple calculation shows that this behavior of the adhesion forces can be ac counted for by the van der Waals and capillary forces between the AFM tips and the substrate.