1. Department of Mechanical Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong SAR, China
2. Nanomanufacturing Laboratory (NML), City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, China
3. CityU-Xidian Joint Laboratory of Micro/Nano-Manufacturing, Shenzhen 518057, China
4. School of Mechano-Electronic Engineering, Xidian University, Xian 710071, China
5. Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen 518055, China