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O: Fachverband Oberflächenphysik
O 44: Scanning probe techniques: Method development – Poster
O 44.13: Poster
Dienstag, 10. März 2026, 14:00–16:00, P2
Nonlinearity mapping using adaptive control schemes in scanning force microscopy — •Lukas Böttcher1, Hannes Wallner2, Niklas Kruse2, Franziska Dorn1, Wolfram Just2, Ingo Barke1, Jens Starke2, and Sylvia Speller1 — 1Institute of Physics, Universität Rostock, Germany — 2Institute of Mathematics, Universität Rostock, Germany
When probing surfaces by scanning force microscopy methods using oscillating cantilevers, bistabilities may occur [1,2]. This is a result of nonlinearities arising due to tip-sample interactions. In this work we focus on the attractive regime. Using an adaptive control scheme we track branches of unstable periodic orbits of the oscillating cantilever, arising between the two stable states [3]. Combining this with a topography scan of a polymer blend surface we explore spatial changes of the unstable branch. Parameters, such as the frequency width of the bistable region or the slope at the unstable branch can serve as nonlinearity parameters and respective maps can be acquired. The aim is to connect such nonlinearity maps to material-related properties such as density and elasticity.
[1] Gleyzes, P. et al.: Bistable behavior of a vibrating tip near a solid surface. Appl. Phys. Lett. 58, 2989 (1991) [2] Misra, S. al.: Event-driven feedback tracking and control483 of tapping-mode atomic force microscopy. Royal Society of London Proceedings484 Series A 464, 2113*2133 (2008) [3] Böttcher, L. et al.: Exposing hidden periodic orbits in scanning force microscopy. Commun Phys 8, 57 (2025)
Keywords: AFM; Nonlinear; Control