Rapid direct deposition of TiH₂ paste for porous Ti scaffolds with tailored porous structures and mechanical properties

We herein demonstrate the utility of the rapid direct deposition of a titanium hydride (TiH₂) paste for the production of porous titanium (Ti) scaffolds with tailored porous structures and mechanical properties. In particular, methylcellulous (MC) polymer was used as the binder, since it can rapidly solidify in acetone through solvent extraction, thus enabling deposited green filaments to have high structural integrity. In addition, TiH₂ powder was used as the Ti source because of its smaller particle size than commercial Ti powder and conversion to Ti metal through a two-step dehydrogenation process. The uses of fine TiH₂ powder and MC binder allowed for the creation of three-dimensionally interconnected periodic macrochannels with sizes of ∼165 ± 14 × 167 ± 25 μm. The produced Ti scaffold had a porosity of ∼42 ± 7 vol % and a reasonably high compressive strength of 48 ± 15 MPa. In addition, the porosity and mechanical properties of porous Ti scaffolds could be tailored simply by adjusting the initial distances between deposited green TiH₂/MC filaments. All of the porous Ti scaffolds produced with various porosities showed good in vitro biocompatibility.