1. Department of Bioengineering, University of California, Berkeley, California 94720, United States
2. Physical Biosciences Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
3. Department of Chemistry, Soonchunhyang University, Asan, Korea 336-745
4. Joint Graduate Group in Bioengineering, University of California, Berkeley, and University of California, San Francisco, California 94720, United States
5. NSK Ltd., Tokyo, Japan
6. Department of Physics and Astronomy, Seoul National University, Seoul, Korea 151-747
7. ARPA-E, U.S. Department of Energy, Washington, DC 20585, United States
8. Berkeley Nanoscience and Nanoengineering Institute, Berkeley, California 94720, United States