Introduction

Atomic Force Microscopy (AFM) is part of the family of near-field microscopies or local probe microscopies. Three-dimensional images are obtained by scanning a surface with a probe.

The first local probe microscope is the tunnel effect microscope (STM) invented in 1982 by Binnig and Rohrer of IBMZurich in which the probe is a conductive metal tip of monoatomic dimension moves at a distance of~1nm, above an electrical conductive sample. The image is obtained by detecting the current of electrons which is established between the tip and the surface, by tunnel effect in quantum mechanics.

The major disadvantage of the tunnel microscope is that it is not suitable for the study of non-conductive materials.In 1986, a method derived from the STM appeared: the atomic force microscope in contact mode to remedy this disadvantage The sample can be conductive or insulating and the image is obtained by detecting the forces of inter-atomic interactions between a tip and the surface.

This tutored project presents more specifically theAtomic force with which the topography of a sample can be observed in 3 dimensions. We first presented its operating principle based on the interaction between a point and a surface. We described the forces involved in this system. We will then discuss the different imaging modes.