CantileverA small springy beam that bends as the tip feels the surface.
Tip (probe)The sharp point that scans the surface of the sample.
SampleThe thing being imaged. It lies on top of the scanner.
Piezoelectric scannerIt moves the sample under the tip very precisely. The tube changes size with voltage.
Tip apexThe very end of the tip, only nanometers across.
Sample surfaceThe surface the tip traces, drawn here as atoms.
Laser and feedback 4
LaserIt shines light onto the back of the cantilever.
PhotodetectorIt senses where the reflected light lands. A bending cantilever moves the spot.
Laser beamIt bounces off the cantilever and onto the photodetector.
Feedback circuitIt adjusts the height to keep the force on the tip steady.
How this list was compiled: Every name checked on 2026-10-01 and kept only where both of these use it. (1) Wikipedia, Atomic force microscopy, https://en.wikipedia.org/wiki/Atomic_force_microscopy : cantilever, tip (probe), tip apex, sample, sample surface, the detector of the cantilever's deflection, laser light from a diode reflected off the back of the cantilever onto a position-sensitive detector made of photodiodes, the feedback loop that keeps the force constant, piezoelectric scanners and the xyz drive. (2) University of Cambridge, DoITPoMS teaching and learning package Atomic Force Microscopy, https://www.doitpoms.ac.uk/tlplib/afm/index.php (pages Introduction, The Scanner, Tip and Cantilever, Feedback): the probe scanned over the sample surface, the scanner as a hollow tube of piezoelectric material, the cantilever with a tip at its end, the apex of the tip, the diode laser focused on the back of the cantilever, the laser beam, the position-sensitive photodetector with four sectors, the feedback circuit. Labels, hints, detail lines and position notes were written for this site. Licence: own work
The drawing: Own drawing from plain geometry; nothing traced. Licence: own work
How it works
The atomic force microscope parts are named here on one schematic: the laser, the cantilever and its tip, the photodetector, the scanner and the feedback circuit. Tap a ring to read what a part does.
Read the full guide
How the parts work together
The scanner moves the sample under a sharp tip at the cantilever's end. Forces between tip and sample surface bend the cantilever. A laser beam reflected off the back of the cantilever lands on the photodetector, and the spot moves as the cantilever bends.
What the feedback circuit does
The feedback circuit reads the photodetector and adjusts the height so the bending stays at a set value. The heights it records, point by point, make up the image of the surface.
The inset shows the tip apex, the very end of the tip, drawn over atoms of the sample surface.
Questions and answers
What are the main parts of an atomic force microscope?
A cantilever with a sharp tip, a laser and a photodetector that read how far the cantilever bends, a piezoelectric scanner that moves the sample or the tip, and a feedback circuit that controls the height.
What does the cantilever do in an AFM?
The cantilever is a small springy beam with the tip at its free end. Forces between the tip and the sample bend it, and that bending is what the microscope measures.
How does an AFM detect the bending of the cantilever?
Most often with a laser beam. The light reflects off the back of the cantilever onto a position-sensitive photodetector, and the reflected spot shifts when the cantilever bends.
Why does an atomic force microscope use a piezoelectric scanner?
Piezoelectric materials change size when a voltage is applied, so the scanner can set the position of the sample or the tip extremely accurately.