Study of falling-down-type DLP 3D printing technology for high-resolution hydroxyapatite scaffolds.

In this study, a strategy to print hydroxyapatite (HA) ceramics based on falling- down-type digital light processing (DLP) 3D printing technology with high accuracy was proposed. The monolayer curing thickness and curing broadening of the samples were compared under different conditions, and the most suitable photoinitiator for the system and optimal amount of additive dye in the slurry were obtained. The light power density and single-layer exposure time of the light source of the DLP printerwere optimized, and anumber of high-resolution models of HA scaffolds with an exact square-channel aperture width of 380 µm were successfully printed. The shrinkage, microstructural, and mechanical properties of the HA ceramic scaffolds were studied at different sintering temperatures. The microstructure and composition of the scaffolds were also characterized by scanning electron microscopy and X-ray diffractometry. The compressive strength and compressive modulus of HA porous scaffold were 11.61 MPa and 1.26 GPa, respectively. And the porosity of scaffold was 31.67%. [ABSTRACT FROM AUTHOR]