1. Materials Department, University of California, Santa Barbara, California 93106, United States
2. Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States
3. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Mechanical Engineering Department, University of California, Santa Barbara, California 93106, United States
5. Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, California 93106, United States