Abstract: The objective of this study is to develop a bio robot with a high degree of biomechanical fidelity to the human musculoskeletal system in order to investigate the biomechanical principles underlying human walking. The robot was designed to possess identical biomechanical characteristics to the human body in terms of body segment properties, joint configurations and 3D musculoskeletal geometries. These design parameters were acquired based on the medical images, 3D musculoskeletal model and gait measurements of a healthy human subject. To satisfy all the design criteria simultaneously, metal 3D printing was used to construct the whole-body humanoid robot. Flexible artificial muscles were fabricated in accordance with the predefined 3D musculoskeletal geometries. A series of physical tests were conducted to demonstrate the capacity of the robot platform. The fabricated robot shows equivalent mechanical characteristics to the human body as originally designed. The results of the physical tests by systematically changing environmental conditions and body structures have successfully demonstrated the capability of the robot platform to investigate the structure-function interplay in the human musculoskeletal system and also its interaction with the environment during walking. This robot might provide a valuable and powerful physical platform towards studying human musculoskeletal biomechanics by generating new hypotheses and revealing new insights into human locomotion science.

Key words: musculoskeletal biomechanics, humanoid robots, biomechanical fidelity, 3D printing, human walking