Direct ink writing of special-shaped structures based on TiO2 inks

Direct ink writing (DIW) method is a novel kind of ceramic fabrication approach which allows one to design and rapidly construct ceramic products in complex shapes without the need for any lithographic masks, dies or expensive moulds. A 40 wt.% water-based titanium dioxide (TiO2) suspension was formulated. With the help of DIW technique, two-dimensional (2D) spiral structures, three-dimensional (3D) woodpile structures, cylindrical structures and half conical structures at micrometer scale were fabricated. According to the rheological test, the ink shows a shear-thinning behavior and appropriate viscoelastic properties, which ensures a feasible shaping process. The scanning electron microscopy (SEM) test shows that the samples sintered at 1050 degrees C for 2 h have formed ceramics completely. The DIW method has merits to pattern ceramics into special-shaped structures into two and three dimensions with high precision and good designability, which provides new ideas and methods for structural, functional and biomedical applications.