1. Empa─Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf, Switzerland
2. Laboratory of Nanoscience for Energy Technology (LNET), École Polytechnique Fédérale de Lausanne, Rte Cantonale, 1015 Lausanne, Switzerland
3. Center for Converging Technnologies, Soft Bioinspired Robotics, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy