[1] City Univ Hong Kong, Dept Phys, Kowloon, Tat Chee Ave, Hong Kong, Peoples R China
[2] Peking Univ, Sch Adv Mat, Shenzhen Grad Sch, Shenzhen 518055, Peoples R China
[3] Chinese Acad Agr Machanizat Sci, Surface Engn & Technol Inst, Beijing 100083, Peoples R China
[4] City Univ Hong Kong, Dept Mat Sci & Engn, Kowloon, Tat Chee Ave, Hong Kong, Peoples R China
[5] City Univ Hong Kong, Dept Biomed Engn, Kowloon, Tat Chee Ave, Hong Kong, Peoples R China