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. Department of Mechanical Engineering National University of Singapore Singapore 117575 Singapore
4. NUS Suzhou Research Institute (NUSRI) Suzhou Jiangsu 215123 China
5. NUS Graduate School's Integrative Sciences and Engineering Programme (ISEP) National University of Singapore Singapore 117583 Singapore