1. Institute of Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany
2. Department of Physics and Technology, University of Bergen, Allégaten 55, 5020 Bergen, Norway
3. FIT Freiburg Centre for Interactive Materials and Bioinspired Technologies, Georges-Köhler-Allee 105, 79110 Freiburg, Germany
4. Cluster of Excellence livMatS @FIT, Freiburg, Germany
5. Frauenhofer IWM, MikroTribologie Centrum μTC, Wöhlerstrasse 11, 79108 Freiburg, Germany
6. Institute of Physics, University of Kassel, Heinrich-Plett-Straße 40, 34132 Kassel, Germany