Abstract: An approach based on CAD and stereolithography rapid prototyping is proposed, which provides precise design and control of internal microstructure for scaffolds, achieves the integrated fabricated of external shape and internal microstructure of scaffolds. According to CT data, external shape of skeleton is reconstructed using CAD software. On the principle of facilitating cell growth and osteogensis, the internal microstructure including pore geometry, size, orientation, interconnectivity and branching is designed. The resin molds of scaffolds are fabricated by stereolithography and the biomaterials are filled into the molds.After biomaterials in situ hardening, the molds are removed by pyrolysis The scaffolds with controlled microstucture are achieved. According to the observation under light microscope, the results indicate that the external shape and internal microstructure of scaffolds are in cornformity with the design. Compared with traditional scaffold fabrications, this method provides enhanced control over scaffold shape and internal microstruture.

Key words: Controlled microstructure, Indirect fabrication, Rapid prototyping, Scaffolds, DOF of link-group, DOF of links, DOF of output link, DOF of mechanism