1. Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208, United States
2. Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands
3. U.S. DEVCOM Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, United States
4. Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, United States