Architecture and implementation of an adaptive nanopositioning controller for fast spiral scanning

Nanopositioning is a key factor for a wide range of applications, such as surface imaging and ultra-high-density probe-based data storage. These applications use scanning probes in order to sense and alter the properties of the underlying medium with nanoscale precision. Recently, new scanning schemes were introduced that can lead to high-speed nanopositioning, if their inherent properties are properly exploited by the tracking control mechanism. The aim for high-speed operation poses stringent requirements to the controller architecture, in terms of speed of execution and arithmetic accuracy. In this paper we present the design of a linear time-varying controller for high-speed, constant linear velocity archimedean spiral scanning. This effort includes the design and implementation of such a control scheme, as well as a flexible multi-board hardware and software test-bed for nanopositioning systems. For proof of concept, the presented controller is applied to an experimental AFM-based scanning probe setup in order to track spiral trajectories efficiently.