1. Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576, Singapore
2. Center for Intelligent Sensors and MEMS (CISM), National University of Singapore, 5 Engineering Drive 1, Singapore 117608, Singapore
3. Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634, Singapore
4. Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575 Singapore
5. NUS Graduate School for Integrative Sciences & Engineering (NGS), National University of Singapore, 21 Lower Kent Ridge Road, Singapore 119077, Singapore