Atomic Force Microscopes - Tutorial Page

Feedback control is used commonly for keeping the motion of an object in a fixed relationship to another object. A simple example of feedback control occurs when you walk down a sidewalk. As you walk down a sidewalk you constantly control your motion by viewing the edge of the sidewalk. If you begin to walk off the sidewalk you correct your motion so that you stay on the sidewalk. Feedback control is used routinely for many common applications such as the automatic control airplanes and controlling the temperature in buildings. In the AFM, feedback control is used to keep the probe in a "fixed" relationship with the surface while a scan is measured.