1. Laboratory for Surface Science
and Technology, Department of Materials, ETH Zurich, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland
2. Light Microscopy and Screening
Center, Department of Biology, ETH Zurich, Schafmattstrasse 18, 8093 Zurich, Switzerland
3. Department of Materials Science
and Technology of Polymers, University of Twente, MESA+ Institute for Nanotechnology, P.O. Box 217, 7500 AE Enschede,
The Netherlands