1. School of Physical Science and Technology ShanghaiTech University 393 Middle Huaxia Road Shanghai 201210 China
2. Department of Civil and Environmental Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA
3. Department of Biomedical Engineering Tufts University Medford MA 02155 USA
4. Department of Chemistry Boston College Chestnut Hill MA 02467 USA
5. Department of Chemistry and Center for Nano and Micro Mechanics Tsinghua University Beijing 100084 China
6. Center for Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA
7. Center for Computational Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA