skannauspintamikroskopia

Scanning probe microscopy, or SPM, is a class of microscopy techniques that use a physical probe to scan a surface and generate a topographic image. This is in contrast to optical or electron microscopes that use electromagnetic waves or beams. The probe, often a sharp tip on a cantilever, interacts with the sample surface, and the deflection of the cantilever or other signals are recorded as the probe is scanned across the sample. This interaction can be based on various physical forces, such as van der Waals forces, electrostatic forces, or magnetic forces.

One of the most common types of SPM is atomic force microscopy, or AFM. In AFM, the tip experiences forces from the sample surface, and the cantilever bends in response. A laser beam reflected off the back of the cantilever is detected by a photodiode, and the changes in the laser spot position reveal the topography. Another important technique is scanning tunneling microscopy, or STM. STM relies on the quantum mechanical tunneling current that flows between a conductive tip and a conductive sample when they are brought very close together. By maintaining a constant tunneling current, the tip can be scanned across the surface, following the contours of the sample. SPM techniques are capable of imaging surfaces at the atomic scale, providing unprecedented detail about surface structure, properties, and modifications. They are widely used in fields such as materials science, nanotechnology, and biology.