Control-observer technique for surface imaging with an experimental platform of Scanning-Tunneling-Microscope type

摘要

This paper proposes a control strategy based on synthesis of robust design techniques with state observer tools, handling nonlinearities in the driving piezoactuators, as well as in the tunneling current for a home-made Scanning-Tunneling-Microscope-like device (STM), allowing to estimate the surface of nano samples. As in standard STM operation, a tip is driven at a fixed (subnanometric) distance above the sample which is scanned. The control approach is illustrated with an example of experimental surface reconstruction, and a comparison with results provided by a commercial STM.