1. School of Science, State Key Laboratory for Mechanical Behaviour of Materials; Collaborative Innovation Center of Suzhou Nano Science and Technology; Xi'an Jiaotong University; Xi'an 710049 Shaan Xi P.R. China
2. State Key Laboratory for Strength and Vibration of Mechanical Structures; International Center for Applied Mechanics and School of Aerospace; Xi'an Jiaotong University; Xi'an 710049 P.R. China
3. Bioinspired Engineering and Biomechanics Center (BEBC); Xi'an Jiaotong University; Xi'an 710049 P.R. China
4. Key Laboratory of Biomedical Information Engineering of Education Ministry; School of Life Science and Technology; Xi'an Jiaotong University; Xi'an 710049 P.R. China
5. School of Engineering and Applied Science; Kavli Institute of Bionano Science and Technology; Harvard University; Cambridge MA 02318 USA