1. Hahn-Schickard, Georges-Koehler-Allee 103, 79110 Freiburg, Germany
2. Hahn-Schickard, Allmandring 9 b, 70569 Stuttgart, Germany
3. CER Groupe, Novalis Science Park, Rue de la Science 8, 6900 Aye, Belgium
4. Laboratory for MEMS Applications, IMTEK—Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103, 79110 Freiburg, Germany