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S. Ito, D. Neyer, J. Steininger, G. Schitter:
"Dual Actuation of Fast Scanning Axis for High-speed Atomic Force Microscopy";
Talk: IFAC 2017 World Congress, Toulouse (France); 07-09-2017 - 07-14-2017; in: "Proceedings of the IFAC 2017 World Congress", (2017), 6 pages.

In order to overcome the limiting trade-off between the imaging speed and scanning
range of an atomic force microscope (AFM), this paper combines two piezoelectric actuators
as a dual stage actuator (DSA) for a lateral motion (X axis) of the AFM probe with respect
to the sample. As the rst actuator, a piezoelectric tube actuator of the commercial AFM
is utilized. Although the actuator realizes a relatively large actuation range, it has the rst
mechanical resonance at a low frequency of 2.5 kHz. In the case of high-speed imaging, this
resonance impairs the imaging speed and quality. In order to overcome this, a piezoelectric
shear actuator with the rst resonance at 19 kHz is selected as the second actuator, combined in
the commercial AFM. To generate the X-axis motion by synchronizing those two actuators, this
paper proposes a feedforward control design for DSAs in the frequency domain, which takes into
account the actuator dynamics. In the proposed approach, triangular raster scan is composed
as a Fourier series by individually adjusting the complex Fourier coefficients for each actuator.
The effectiveness of the DSA and its control is validated by experimental AFM imaging at a
scan rate of 200 Hz, where the lowest frequency component is applied to the tube actuator and
the other higher components of the scanning signal to the high-speed shear actuator.

Micro and Nano Mechatronic Systems, Motion Control Systems

https://publik.tuwien.ac.at/files/publik_260559.pdf