1. Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia
2. Faculty of Mechanical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia
3. East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule Regensburg, 93053 Regensburg, Germany
4. Jožef Stefan Institute, 1000 Ljubljana, Slovenia