Analog Control of a High-speed Atomic Force Microscope Scanner

A XYZ scanner is designed for fast and high resolution atomic force microscopy. The objective of this paper is to achieve a large scanning bandwidth along the X and Y axis of the scanner. Finite element analysis of the designed scanner is reported along with the experimental determination of the dynamics. Both suggest the presence of first resonant modes around 8.8 kHz and 8.9 kHz along the X and Y axis respectively. Actuating the scanner at frequencies beyond 1% of the first resonance causes mechanical vibrations and hence degradation of the images generated. Controllers are designed, using the Integral Resonant Control methodology, to damp the resonant modes, to enable fast actuation. Due to the large bandwidth of the designed scanner, a Field Programmable Analog Array (FPAA) is used for analog implementation of the controllers. High resolution images are generated at faster scanning rates in closed loop.