1. Department of Physics, Faculty of Science, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore, National University of Singapore Nanoscience and Nanotechnology Initiative Singapore, (NUSNNI), 2 Science Drive 3, Singapore 117542, Singapore, Division of Bioengineering, National University of Singapore, Blk E3A, 9 Engineering Drive 1, Singapore 117576, Singapore, and Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576,...