1. Department of Mechanical Engineering, National Chung Hsing University, Taichung 40227, Taiwan
2. Graduate Institute of Biomedical Engineering, National Chung Hsing University, Taichung 40227, Taiwan
3. Program in Tissue Engineering and Regenerative Medicine, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan