As the tip scanned across a surface, atomic forces (like Van der Waals, electrostatic, or capillary forces) cause the cantilever to deflect.
Works on samples without needing a gold coating.
AFM has moved far beyond simple "pictures." It is now a lab-on-a-tip:
Researchers use AFM to visualize the double helix of DNA or the movement of protein channels in living cell membranes under physiological conditions (liquid environments).
It measures nanomechanical properties —how hard, elastic, or sticky a new composite material is at a specific point.
To prevent the tip from crashing or losing contact, a piezoelectric scanner adjusts the height of the sample or the tip in real-time to maintain a constant force. This vertical movement is what creates the 3D topographic map. 2. Primary Imaging Modes
A laser beam reflects off the back of the cantilever onto a photodiode detector . Even a tiny movement of the tip translates into a measurable shift in the laser’s position.
The core of an AFM is a with a sharp probe (tip) at its end. This tip typically has a radius of curvature on the scale of a few nanometers.