1. Danubia NanoTech, s.r.o., Ilkovičova 3, 812 19 Bratislava, Slovakia, Austrian Research Centers, A-2444 Seibersdorf, Austria, Max-Planck Institut für Festkörperforschung, Heisenbergstr.1, Stuttgart, Germany, Micro- and Nano- Scale Engineering, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands, and ENEA C.R. Portici, Portici, Italy