1. Department of Mechanical Engineering & Materials Science Washington University in St. Louis St. Louis MO 63130 USA
2. Bioinspired Engineering & Biomechanics Center Xi'an Jiaotong University Xi'an 710049 China
3. Gladys Levis Allen Laboratory of Plant Sensory Physiology, Biology Department Washington University in St. Louis St. Louis MO 63130 USA
4. Qian Xuesen Laboratory of Space Technology China Academy of Space Technology Beijing 100094 China
5. Ministry of Education Key Laboratory of Biomedical Information Engineering, School of Life Science & Technology Xi'an Jiaotong University Xi'an 710049 China