1. Department of Materials Science and Engineering, National University of Singapore, Singapore 117574
2. Department of Mechanical Engineering, National University of Singapore, Singapore 117575
3. Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 138632
4. Singapore Institute of Manufacturing Technology, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis, Singapore 138634
5. Department of Applied Physics, School of Advanced Engineering, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015 Japan
6. Collaborative Open Research Center, Kogakuin University, 2665-1 Nakano, Hachioji, Tokyo 192-0015, Japan
7. National University of Singapore Chongqing Research Institute, Chongqing 401123, P. R. China