1. Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
2. Department of Materials Science and Engineering, National University of Singapore (NUS), 9 Engineering Drive 1, Singapore 117575, Republic of Singapore
3. Department of Biomedical Engineering, National University of Singapore (NUS), 4 Engineering Drive 3, Singapore 117583, Republic of Singapore