[1] Natl Cheng Kung Univ, Coll Med, Inst Oral Med, Tainan 70101, Taiwan
[2] Natl Tsing Hua Univ, Dept Power Mech Engn, Hsinchu, Taiwan
[3] Ind Technol Res Inst, Nanotechnol Res Ctr, Hsinchu, Taiwan
[4] City Univ Hong Kong, Dept Mech & Biomed Engn, Kowloon, Hong Kong, Peoples R China