Atomic force microscopy supplies researchers and developers extremely high resolution topographical data from a large number of different minerals, polymers, mixtures, composite materials or biological tissue. This technology, developed in the 1980s, enables users to obtain subatomic resolved images of sample surfaces.
The principle is very simple: A fine needle with a point tapered to the size of just a few atoms is pulled over the sample to be examined. Atomic forces interact between the outermost atom of the needle and the atom of the surface closest to the needle. The effect of the force of the surface on the needle is measured by laser optics.
WITec GmbH, a company based in the German city of Ulm, has developed a special implementation of the principle of obtaining the signal in this way and transferring it to the control of the sample stage. Its Z-position is adjusted so that the same force always acts on the needle. Therefore, the stage position provides the coordinates of the surface topography immediately and the sample stage represents the heart of WITec's atomic force microscopes.