1. Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong SAR P. R. China
2. Division of Integrative Systems and Design Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong SAR P. R. China
3. Research Institute of Intelligent Wearable Systems The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong SAR P. R. China
4. Department of Applied Biology & Chemical Technology and Research Institute for Smart Energy The Hong Kong Polytechnic University Hong Kong P. R. China