On noncontact Atomic Force Microscopy control for interaction force and surface reconstruction

A control strategy is here investigated in order to improve the measurement performances in Atomic Force Microscopy (AFM), in particular with respect to thermal noise. This strategy is exemplified by an observer-controller scheme for topography detection and interaction force reconstruction. The proposed state feedback and observer designs are based on a simple low order model, but which includes nonlinearities due to interaction forces, as well as the strongly disturbing effects of thermal noise. Some corresponding simulation results are then presented as an illustration of the proposed approach.