1. Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
2. Center for Intelligent Sensors and MEMS (CISM), National University of Singapore, Singapore 117608, Singapore
3. Suzhou Research Institute (NUSRI), National University of Singapore, Suzhou Industrial Park, Suzhou 215123, China
4. NUS Graduate School - Integrative Sciences and Engineering Programme (ISEP), National University of Singapore, Singapore 119077, Singapore