1. Department of Informatics and Microsystem Technology; University of Applied Sciences Kaiserslautern; Amerikastr. 1 66482 Zweibrücken Germany
2. Institute of Nano- and Biotechnologies (INB), FH Aachen; Heinrich-Mußmann Str. 1 52428 Jülich Germany
3. Experimental Physics; Saarland University; 66123 Saarbrücken Germany
4. Department of Physics IA; RWTH Aachen; Sommerfeldstr. 14 52074 Aachen Germany
5. Department of Soft Matter and Biophysics; Katholieke Universiteit Leuven; Celestijnenlaan 200 D 3001 Leuven Belgium
6. Institute for Materials Research; Hasselt University; Wetenschappspark 1 3590 Diepenbeek Belgium