Abstract
We examined friction and pull-off forces on the nano-scale asperity covered by a Self-Assembled Monolayer (SAM) or a Langmuir-Blodgett film (LB film). The nano-scale asperities were covered by SAMs or LB films having six different lengths of the alkyl chain. The friction and pull-off forces were measured by using an atomic force microscope (AFM) having a square flat probe. The results showed that friction and pull-off forces on the nano-scale asperity covered by a SAM or a LB film were proportional to the radius of curvature of the asperity peak and decreased with longer the alkyl chain lengths. The frictional characteristics were influenced by the number of contact points, different types of moleculer attachment to the silicon surface and interactive forces among the alkyl chains.
