1. Laboratory
for Multifunctional Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
2. Fraunhofer Institute
for Mechanics of Materials IWM, Woehlerstrasse
11, 79108 Freiburg, Germany
3. Freiburg
Materials Research Center, University of Freiburg, Stefan-Meier-Strasse
21, 79104 Freiburg, Germany
4. FIT
Freiburg Centre for Interactive Materials and Bioinspired Technologies, University of Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany