Publications in Scientific Journals:
S. Ito, G. Schitter:
"Atomic Force Microscopy Capable of Vibration Isolation with Low-stiffness Z-axis Actuation";
Ultramicroscopy,
186
(2018),
9 pages.
English abstract:
For high-resolution imaging without bulky external vibration
isolation, this paper presents an atomic force microscope (AFM) capable of vibration isolation with its internal Z-axis (vertical) actuators moving the AFM probe. Lorentz actuators (voice coil actuators) are used for the Z-axis actuation, and flexures guiding the motion are designed to have a low stiffness between the mover and the base. The low stiffness enables a large Z-axis actuation of more than 700 μm and mechanically isolates the probe from floor vibrations at high frequencies. To reject the residual vibrations, the probe tracks the sample by using a displacement sensor
for feedback control. Unlike conventional AFMs, the Z-axis actuation attains a closed-loop control bandwidth that is 35 times higher than the first mechanical resonant frequency. The closed-loop AFM system has robustness against the flexures´ nonlinearity and uses the first resonance for better sample tracking. For further improvement, feedforward control with a vibration sensor is combined, and the resulting system rejects 98.4% of vibrations by turning on the controllers. The AFM system is demonstrated by successful AFM imaging in a vibrational environment.
Keywords:
Atomic force microscopy, Vibration isolation, Voice coil actuators, Robust control
"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1016/j.ultramic.2017.12.007
Electronic version of the publication:
https://publik.tuwien.ac.at/files/publik_263910.pdf
Created from the Publication Database of the Vienna University of Technology.