Continuous toolpath planning for 3D heterogeneous porous structures

Toolpath planning for porous structures is of particular interest in solid freeform fabrication (SFF) and tissue engineering. This paper presents a new multi-material based toolpath planning methodology for fabricating hollow structures. The ruled surface generated in our earlier work is used to develop toolpath planning. Ruling lines are reoriented to enable continues and uniform size multi-material printing layer-by-layer. Firstly, all ruling lines are matched and connected to eliminate start and stops during printing. Then, regions with high number of ruling lines are relaxed using a ruling line relaxation technique to eliminate over deposition. A novel layer-by-layer deposition process is progressed in two consecutive layers: The first layer ruling line based raster pattern and the next layer with spiral pattern deposition. Heterogeneous material properties are mapped based on the parametric distances from the material features. Example toolpaths are presented in this paper.