1. Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montréal, QC, Canada H3A 1B1
2. Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montréal, QC, Canada H3A 0C3
3. Department of Materials, ETH Zürich, 8093 Zürich, Switzerland
4. Theoretical and Applied Mechanics Program, Northwestern University, Evanston, IL 60208, USA