1. Materials Science & Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
2. Department of Civil & Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3109, United States
3. Center
for Hierarchical Materials Design, Northwestern University, Evanston, Illinois 60208-3109, United States
4. Department of Materials Science & Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3109, United States
5. Department
of Mechanical Engineering, Northwestern University, 2145 Sheridan
Road, Evanston, Illinois 60208-3109, United States