1. Center for Converging Technologies, Bioinspired Soft Robotics, Istituto Italiano di Tecnologia, Via Morego 30, 16065 Genova, Italy
2. Unconventional Computing Laboratory, University of the West of England, Coldharbour Lane, Bristol BS16 1QY, UK
3. The Cyberforest Experiment, Costa Bocche, Località Paneveggio, 38037 Predazzo, Italy
4. Department of Physics “E.R. Caianiello”, Universitá degli Studi di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy
5. Faculty of Computer Science, Multimedia and Telecommunications, Universitat Oberta de Catalunya, Rambla del Poblenou 156, 08018 Barcelona, Spain