Dresden 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 48: Scanning Probe Methods I
O 48.7: Vortrag
Mittwoch, 2. April 2014, 12:00–12:15, GER 38
Visualizing the Subsurface of Soft Matter: Simultaneous Topographical Imaging, Depth Modulation, and Compositional Mapping with Triple Frequency Atomic Force Microscopy — •Daniel Ebeling1,2, Babak Eslami2, and Santiago D. Solares2 — 1Institute of Applied Physics, Justus Liebig University Giessen, Giessen, Germany — 2Department of Mechanical Engineering, University of Maryland, College Park, Maryland, United States
Characterization of subsurface morphology and mechanical properties with nanoscale resolution and depth control is of significant interest in soft matter fields like biology, polymer science, where buried structural and compositional features can be important. However, controllably "feeling" the subsurface is a challenging task for which the available imaging tools are relatively limited. In this paper, we propose a trimodal atomic force microscopy (AFM) imaging scheme, whereby three eigenmodes of the microcantilever probe are used as separate control "knobs" to simultaneously measure the topography, modulate sample indentation by the tip during tip-sample impact, and map compositional contrast, respectively. We illustrate this multifrequency imaging approach through computational simulation and experiments conducted on ultrathin polymer films with embedded glass nanoparticles in ambient air. By actively increasing the tip*sample indentation using a higher eigenmode of the cantilever, we are able to gradually and controllably reveal glass nanoparticles which are buried tens of nanometers deep under the surface, while still being able to refocus on the surface.