1. Department of Electrical & Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117576, Singapore
2. Center for Intelligent Sensors and MEMS (CISM), National University of Singapore, 5 Engineering Drive 1 Singapore 117608, Singapore
3. National University of Singapore Suzhou Research Institute (NUSRI), Suzhou Industrial Park, Suzhou 215123, China
4. NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 119077, Singapore