Calibration of lateral force of AFM measurement

Atomic force microscope (AFM) is a useful apparatus for measuring interaction forces between an AFM tip and samples at nanoscale. These forces can be classified into a normal force and a lateral force based on the deformation of AFM cantilever. The reliability of the measurement result is influenced by calibrating the spring constant of the AFM probe directly. However, it is still a challenge to quantitative lateral force because current calibration of lateral signal is complicated. Here, we present a simple experimental procedure to calculate a calibration factor of lateral force of a cantilever, and the method can be applied to most commercial AFM probes with rectangular cantilever.