ROLE OF THE FORCE OF FRICTION ON CURVED SURFACES IN SCANNING FORCE MICROSCOPY

Among near field microscopes, the atomic force microscope (AFM) is a powerful and versatile tool for investigating local mechanical properties, friction and adhesiveness. Especially, the knowledge of the contribution of the friction may become of primary importance to understand the structure of the objects deposited on a surface. In this paper, we show that the contribution of the force of friction lying in the tangent contact plane between the tip and the object is dependent on the geometry of the object scanned. A tip scanning a curved surface is considered and a general expression is derived describing the two contact modes in AFM: constant force and constant height.