1. Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College of Chongqing University; Chongqing 400030 China
2. Institute of Biomedical Engineering, School of Preclinical and Forensic Medicine, Sichuan University; Chengdu 610041 China
3. Department of Mechanical and Aerospace Engineering; Center for Surface Science and Plasma Technology, University of Missouri; Columbia Missouri 65211