Atomic force microscope (AFM)

Atomic force microscope is a type of scanning probe microscope that records the force between the probe and the specimen. The working principle of an AFM can be understood like this: Consider yourself to be in a dark room in front of a table. The table has a book, a pen, a wristwatch, a spoon, a fork, and a screw driver. Will you be able to selectively lift the spoon if asked to do so? The answer for most people is yes. You can distinguish two distinct objects by touching them with your fingers. In this example, your fingers act as the probes, your arm acts as the positioner of your fingers, and your brain works as the processing unit. An AFM works exactly the same way; it has three basic components: a probe, a positioner, and a processing unit. Figure 19.2 shows the diagram and the working principle of an AFM.

 

Figure 19.2 A schematic diagram of an atomic force microscope. The working principle is discussed in the text.