1. Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States
2. Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
3. National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
4. Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California 94720, United States
5. Department of Chemical and Biological Engineering, University of Wisconsin–Madison, Madison, WI 53706, United States