1. Ultrahigh Precision Fabrication Team, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. Fax: +81-48-462-4655; Tel: +81-48-467-9315
2. VCAD System Research Program, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
3. Department of Biomechanics, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo, Kyoto 606-8507, Japan. Fax: +81-75-751-4853; Tel: +81-75-751-4853