Regensburg 2010 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 17: Interfaces and Thin Films I
CPP 17.8: Vortrag
Dienstag, 23. März 2010, 11:45–12:00, H39
Surface plasmon induced structuring of azobenzene thin polymer films — •Nataraja Sekhar Yadavalli1, Tobias König2, and Svetlana Santer3 — 1Department of Microsystems Engineering (IMTEK), Freiburg — 2Freiburg Institute for Advanced Studies (FRIAS), Freiburg — 3Department of Experimental Physics, Potsdam
There is a strong demand on methods for precise manipulation of nano-objects on surfaces. Recently we report on a phenomenon observed with a certain type of thin polymer films, suggesting that the substrate by itself can induce motion of adsorbed objects (Santer, 2006). The proposed mechanism of motion is based on a dynamically fluctuating force field, emerging during topography switching. It results in competing surface forces acting on the particle, which leads to a motion and repositioning of the particle. In this work, we choose UV-illumination for changing the topography of photosensitive thin polymer films. Here we present azo thin films (Seki, 2007) with integrated optically active elements supposed to support and steer the response of polymer films to external illumination. The nano-scale metallic structures were fabricated on glass substrate using Au/Ag by colloidal lithography. During irradiation the surface plasmon waves are generated on a metallic mask, which results in printing of near field intensity distributions into topography with the pattern size below the diffraction limit. We found that the topography can be driven reversible. We examined the influence of size of the metallic patterns. The results are confirmed by FDTD simulations and compared with imprints of photolithographic mask.