1. Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Block EA, Singapore 117575, Singapore
2. Institute of Flexible Electronics, Xi’an Key Laboratory of Flexible Electronics, Northwestern Polytechnical University, Xi’an 710072, China
3. Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Block E4, Singapore 117583, Singapore
4. School of Mechanical Engineering, Shanghai Jiaotong University, F306 Mechanical Building 800 Dongchuan Road Minhang, Shanghai 200240, China