Polymer surface imaging: atomic force microscopy

Atomic force microscopy belongs to the family of local probe microscopies.

One of the main aims of near-field microscopy is to image the surface of a material in real direct space, with a spatial resolution ranging from a few tens of micrometers to a tenth of a nanometer. The principle is simple: a small probe is placed close to the surface; by scanning the probe over the surface, a three-dimensional image of the surface is obtained, reflecting the probe-surface interaction.

With the atomic force microscope, the probe is a metal tip, and the image is obtained by detecting the interaction forces between the atoms on the tip and those on the surface.

At present, there are several types of atomic force microscopy, which can be grouped into three families:

• Contact microscopy: the tip is placed in contact with the surface under study;

• Microscopy in non-contact or resonant mode: the tip is placed a few tens of nanometres from the surface;

• intermittent mode microscopy: the tip comes into contact with the surface intermittently.

In this article, we will study the application of this type of microscopy to polymer surface imaging.