1. Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy
2. MEMS Research Lab., Department of Mechanical Engineering, College of Engineering, San Diego State University, 5500 Campanile Drive, San Diego, California 92182-1323 and Center for Sensorimotor Neural Engineering (CSNE), Box 37, 1414 NE 42nd St., Suite 204, Seattle, Washington 98105-6271
3. Electron Microscopy Facility, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
4. Materials Characterization Facility, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
5. Center for Translational Neurophysiology of Speech and Communication, Istituto Italiano di Tecnologia, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy and Section of Human Physiology, University of Ferrara, Via Fossato di Mortara 17/19, 44121 Ferrara, Italy