Principle

In the intermittent contact mode, the cantilever is excited to oscillate near its resonance frequency and during scanning an electronic feedback loop ensures that the oscillation amplitude remains constant.

When the tip is brought close to the sample the forces between the tip and the sample will cause a shift of the resonance curve of the cantilever. If the cantilever is excited at a fixed frequency, the amplitude of the oscillation changes.

This change is detected by the photodiode and a controller
changes the distance between tip and sample so that the preset amplitude remains constant.

Intermittent contact mode animation

Surface of polyelectrolyte multilayers at controlled pH

Magnetic nanoparticles adsorbed on a silicon surface