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. Department of Life Sciences, Albstadt-Sigmaringen University, 72488 Sigmaringen, Germany