1. Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China
2. Institute of Textiles and Clothing, The Hong Kong Polytechnic University, 11 Hong Chong Road, Hong Kong, China
3. Department of Mechanical and Biomedical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, China
4. Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518000, China