Dresden 2011 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 68: Polymeric biomolecular films

O 68.1: Vortrag

Donnerstag, 17. März 2011, 11:15–11:30, WIL B122

Dynamic photothermal laser manipulation of surface-grafted thermoresponsive polymer brushes — •Crispin Amiri Naini, Steffen Franzka, Sven Frost, Mathias Ulbricht, and Nils Hartmann — Fakultät für Chemie, CeNIDE, NETZ, Universität Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany

Stimuli-responsive polymers have become a versatile material in designing smart functional devices, e. g. as adaptive microoptics, microfluidic chips, membranes and sensors. Controlled reaction schemes allow one to build up surface-grafted polymer brush films with thicknesses from the submicron down to the sub-100 nm range [1]. This opens up an avenue towards highly integrated device structures with unprecedented functionalities. In order to stimulate miniaturized polymeric components, e. g. for valving, suitable techniques are required. Here, we demonstrate a facile noncontact laser technique for switching of surface-grafted poly-n-isopropylacrylamide brushes at the water/substrate interface. A modulated beam of a microfocused laser at a wavelength of 532 nm is used to heat the substrate surface and locally trigger swelling and deswelling of the polymer film. Switching on length scales from millimeters down to a few microns is feasible at very low laser power densities. Also, in conjunction with masks, parallel switching at distinct surface areas can be carried out. Prospects in micro- and nanofluidic applications, e. g. in designing freely configurable device structures, are discussed.

[1] M. Mathieu, A. Friebe, S. Franzka, M. Ulbricht, N. Hartmann, Langmuir 25 (2009) 12393.