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G. Schitter, N. Phan:
"Field programmable analog array (FPAA) based control of an Atomic Force Microscope";
Talk: 2008 American Control Conference, Seattle (USA); 06-11-2008 - 06-13-2008; in: "Proceedings of the 2008 American Control Conference", (2008), 2690 - 2695.

For topography measurements and faster imaging
with the AFM a high control-bandwidth is required. This paper
presents an analog implementation of a model-based controller
for a high-speed Atomic Force Microscope (AFM) using a
new type of control hardware. The vertical positioning axis
of the AFM scanner is modeled, and the imaging bandwidth is
improved by means of model-based control. The new feedback
controller, which is designed in the H-infinity-framework, is implemented
on a Field Programmable Analog Array (FPAA), which
enables operation of the model-based controlled AFM system
at a feedback bandwidth on the order of 100 kHz.
Measured results demonstrate that the closed-loop system
recovers from a step-like disturbance within 7 microseconds.
Recorded AFM images verify a significant performance improvement
of the model-based controlled system over the analog
proportional-integral (PI) controlled AFM.