1. Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
2. College of Polymer Science and Engineering, College of Biomedical Engineering, State Key Laboratory of Polymer Materials and Engineering, Sichuan University, 610065 Chengdu, China
3. Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
4. Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
5. Department of Electrical and Electronic Engineering, Joint Appointment with School of Biomedical Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China