1. State Key Laboratory of New Ceramics and Fine Processing
2. School of Materials Science and Engineering
3. Tsinghua University
4. Beijing 100084
5. P. R. China
6. Department of Materials Science and Engineering
7. Massachusetts Institute of Technology
8. Cambridge
9. USA
10. Department of Biomedical Engineering
11. Case Western Reserve University
12. Cleveland
13. Guifeng Zhang
14. State Key Laboratories of Biochemical Engineering
15. Institute of Process Engineering
16. Chinese Academy of Science
17. Beijing 100190