Piezoelectric-pneumatic micro-jet printing of high viscous piezoelectric slurry

3D printing piezoelectric ceramic has provided solutions for personalized electronic devices due to the capability of fabricating intricate 3D structures. However, as the ceramic powder size decreases and solid content increases, 3D printing technology encounters limitations due to the high viscosity, long exposure times, and heavy scattering of the ceramic slurry. In this study, a new piezoelectric-pneumatic micro-jet (PPMJ) printing method with a wide viscosity range based on barium titanate (BTO) slurry is proposed. BTO slurry with 100 nm particle size is optimized for homogeneity and printability. The effects of dispersant types on slurry are studied and the optimal concentration of the dispersant is determined. Based on PPMJ printing, BTO slurry of 50 vol % with a viscosity of 383,135mPa·s can be printed with a 0.2 mm diameter printhead nozzle. After post-processing, the density can reach 5.7 ± 0.023 g/cm³ and it is as same as dry pressing pellets, which is 95 ± 0.4 % of the empirical value. The printed ceramic exhibits excellent dielectric properties (ε_r=572.7±1.1 and tanδ=0.0362±0.0001 at 1KHz) and piezoelectric property (d₃₃=133±1.3). The results indicate that PPMJ is a promising 3D printing technology to fabricate piezoelectric materials with high solid content and complex geometries for the applications of ceramic components.