1. Department of Mechanical Engineering, State University of New York at Binghamton, Binghamton, New York 13902-6000, USA
2. Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy
3. Centre for Materials and Microsystems, Fondazione Bruno Kessler, Povo (Trento), Italy
4. School of Engineering and Materials Science, Queen Mary University of London, London, United Kingdom