1. Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
2. Laboratory for MEMS Applications, IMTEK-Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
3. BIOSS - Centre for Biological Signalling Studies, University of Freiburg, 79110 Freiburg, Germany