Research On The Freeform Direct Writing Technique Based On Ceramic Ink

Direct ink writing（DIW） technique is a kind of novel solid freeform fabrication techniques, which provides a larger potentialthan the traditional fabrication methods in the field of fine ceramic fabrication.Compared with other freeform fabrication techniques, DIW can fabricate fine three-dimensional（3D） structures without any tools, laser or ultraviolet lightat room temperature.The investigations of D IW processing and applications are important for the production of tiny ceramic device. In this paper, the process and applications of direct ink writing were investigated based on various ceramic inks.The whole process of direct ink writing was systematic investigated, including powder processing, preparation of inks, structure production, drying and sintering process, as well as the characterization of properties. The DIW method is flexible in the structure design. Based on the choices of solvent and dispersants, the preparation of ideal ink was discussed. Th e key skills of DW process were investigated by the help of fabrication parameters.3D structures with various shapes were fabricated by DW technique based on PLZT powders. The rheological behaviors of the PLZT ink and the minimum feature sizes were investigated by the comparison of differentsolvent. 3-3 PLZT-Epoxy composites were fabricated after the ceramic infiltrated with Epoxy, which have higher hydrostatic figure of merit dhgh（4112×10-15 m2/N） than that of the normal PLZT piezoelectric ceramics（365×10-15 m2/N）, as well as the 3-3 PZT composite fabricated withinjection method（4020×10-15m2/N）. 3D structures were fabricated by using KNN powders, the electrical parameters were measured toshow the flexible structure design of DIW technique.3D porous catalysts were fabricated by D IW method based on the Ti O2 andα-Fe₂O₃ powders. The relationship between structure and photocatalytic efficiency was proved by the structure design. Compared with the bulk catalyst fabricated by the traditional methods, the porous catalyst produced by DW technique has a better photocatalytic performance.3D biological ceramic scaffolds were fabricated by using the hydroxyapatite（HAp） ink, which was prepared by mixing the ethanol and Vaseline. The proliferation of Hep G2 cells on the 3D HAp scaffolds proves its biocompatibility, and the DW method offers good structure designabil ity and precise control of porosity to induce the cell proliferation. 3D porous tissue scaffolds were fabricated by using DW method based on Zr O 2 inks. The relationship between porosity and compressive strength was discussed by mechanical test. The biocompatibility of Zr O2 was proved by seeding HCT116 cells. Compared with the HAp scaffolds, the Zr O 2 scaffolds have a better mechanical property, which reveals a potential in the application of bone repair.