Patent ID: 7509844

Claim:
A method of automatically detecting a setpoint useful in controlling a tip-to-sample distance of an atomic force microscope (AFM), comprising: a) adjusting a tip of the AFM relative to a sample to establish an initial tip-to-sample distance; b) enabling a feedback mechanism; c) reducing an amplitude setpoint of the feedback mechanism, thereby causing a reduction of the tip-to-sample distance; d) monitoring at least a phase signal provided by a detector; e) repeating steps c)-d) until at least one of: an abrupt change or approaching abrupt change in the phase signal provided by the detector is detected; f) recording an amplitude setpoint corresponding to the detected change in the phase signal for subsequent use in operating the AFM; and g) repeating steps a)-f) using different AFM probe tips to generate a table of setpoints useful in controlling a tip-to-sample distance of an atomic force microscope (AFM) using the different probe tips.