Dresden 2009 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 13: POSTERS Polymer Physics

CPP 13.26: Poster

Dienstag, 24. März 2009, 14:00–16:30, P3

Toroidal Microcavities Produced by Self-Rolling of Strained Polymer Bilayer — •Kamlesh Kumar¹, Valeriy Luchnikov², and Manfred Stamm Stamm¹ — ¹Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany — ²Institute de Chimie des Surfaces et Interfaces, rue Jean Starcky 15, 68057 Mulhouse, France.

We have demonstrated the fabrication of microtoroids by self-rolling of crosslinked thin strained bilayer polymer films, composed of polystyrene (PS)/poly (4-vinyl pyridine) (P4VP) and released in controllable manner from a solid substrate. The toroids formation proceeds from a circular opening in the film made by photolithography or by mechanical scratching followed by immersion of patterned sample in 2 wt % dodecylbenzene sulfonic acid solution (DBSA). DBSA forms supramolecular complexes with pyridine rings of P4VP and increases the specific volume of the polymer. Since the PS layer is neutral in this solution, bilayer film develops strain due to unequal swelling of polymers in solution of DBSA and hence the film bends and scrolls in order to minimize its free energy. The increasing radius of the toroid causes lateral strain in the film, such that the strain isolines are closed concentric circles centered at the middle of the lithographic window. Furthermore, the kinetics of toroid formation is also studied. The toroids with metallic inner surface are promising for the future research as IR-frequency range resonators.

[1] V. Luchnikov, K. Kumar, M. Stamm, J. Micromech. Microeng. 2008, 18, 035041