There are two primary methods for measuring the force between a probe and a sample:

Contact mode and vibrating mode.Contact mode entails a direct quasi-static force versus distance measurement, that is, a rather intimate contact between probe and surface.While producing accurate results, it tends to rapidly damage both probe and surface. Vibrating mode may be either large amplitude,in which the probe contacts the surface on every cycle, or small amplitude non-contact.The latter is generally less stressful on both the probe and surface, and tends to give superior results. It measures more subtle properties ofthe surface.