Overview of coupling effects on interaction forces in micro-nano-world.

The release of object during robotic micromanipulation operations stays a challenge. The adhesion forces have to be known to improve micromanipulation tasks. Adhesion models build from macrophysics (continuum mechanics) or from nanophysics (atomic scale interactions) do not fit well experiments on the microscale. This is due to some phenomenon which are specific to the microphysics. Some of them are developed in this article. First, it is shown that the charges distributions observed on the microscale would have negligible effects on the nanoscale but disturbs significantly micromanipulation. Secondly, the impact of both chemical functionalisation and physical structuration of the surfaces on microscale are presented. Third, during the contact between two objects, the van der Waals forces induces significant local deformations on the microscale contrary to nanosclae where the deformation is negligible. This article shows some typical differences between microscale and nanoscale.