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S. Kuiper, A. J. Fleming, G. Schitter:
"Dual Actuation for High Speed Atomic Force Microscopy";
Talk: 5th IFAC Symposium on Mechatronic Systems, Boston, USA; 09-13-2010 - 09-15-2010; in: "Proceedings of the 5th IFAC Symposium on Mechatronic Systems", (2010), 220 - 226.

In atomic force microscopy (AFM) the imaging speed is strongly limited by the bandwidth of
the feedback loop that controls the interaction between the measurement tip and the sample.
A significant increase in closed-loop bandwidth can be achieved by combining a long-range,
low-bandwidth actuator with a short-range, high-bandwidth actuator, forming a dual actuated
system. This contribution discusses the design of a model-based feedback controller that controls
the tip-sample interaction in dual actuated AFM. In order to guarantee closed-loop stability, the
dynamic uncertainties of the system are identified and taken into account in the controller design.
Two different design cases are discussed, showing the trade-off between the positioning range
at lower frequencies and the positioning range at higher frequencies. The designed feedback
controller is implemented on the prototype AFM system and demonstrates a disturbance
rejection bandwidth of 20 kHz.

Atomic Force Microscopy, model-based control, piezoelectric actuator, dual actuation.