3D Bioplotter Research Papers

Microlattices with orthogonal 0-90° architecture are 3D-extrusion printed from inks containing a blend of oxide powders (Co3O4, CuO, Fe2O3, and NiO) and metal powder (Cr). Equiatomic CoCrCuFeNi microlattices with ∼170 µm diameter struts are then synthesized by H2-reduction of the oxides followed by sintering and interdiffusion of the resulting metals. These process steps are studied by in-situ synchrotron X-ray diffraction on single extruded microfilaments (lattice struts) with ∼250 µm diameter. After reduction and partial interdiffusion at 600 ˚C for 1 h under H2, filaments consist of lightly-sintered metallic particles with some unreduced Cr2O3. A reduced, nearly fully densified (porosity: 1.6 ± 0.7%)…

SnO2-Ag composites with designed architectures with sub-millimeter feature sizes can provide enhanced functionality in electrical applications. SnO2-Ag composites consisting of a ceramic SnO2 micro-lattice filled with metallic Ag are created via a hybrid additive manufacturing method. The multistep process includes: (i) 3D extrusion printing of 0/90° cross-ply micro-lattices from SnO2-7%CuO nanoparticle-loaded ink; (ii) thermal treatment in air to burn the binders and sinter struts of the SnO2 micro-lattice to ~94% relative density; (iii) Ag melt infiltration of channels of sintered micro-lattices. Densification of the SnO2 struts during air-sintering is accelerated by CuO liquid phase forming at 1100°C. During the subsequent…

Additive manufacturing of high-entropy alloys combines the mechanical properties of this novel family of alloys with the geometrical freedom and complexity required by modern designs. Here, a non-beam approach to additive manufacturing of high-entropy alloys is developed based on 3D extrusion of inks containing a blend of oxide nanopowders (Co3O4 + Cr2O3 + Fe2O3 + NiO), followed by co-reduction to metals, inter-diffusion and sintering to near-full density CoCrFeNi in H2. A complex phase evolution path is observed by in-situ X-ray diffraction in extruded filaments when the oxide phases undergo reduction and the resulting metals inter-diffuse, ultimately forming face-centered-cubic equiatomic CoCrFeNi alloy. Linked to the phase evolution…

A new method for complex metallic architecture fabrication is presented, through synthesis and 3D-printing of a new class of 3D-inks into green-body structures followed by thermochemical transformation into sintered metallic counterparts. Small and large volumes of metal-oxide, metal, and metal compound 3D-printable inks are synthesized through simple mixing of solvent, powder, and the biomedical elastomer, polylactic-co-glycolic acid (PLGA). These inks can be 3D-printed under ambient conditions via simple extrusion at speeds upwards of 150 mm s–1 into millimeter- and centimeter-scale thin, thick, high aspect ratio, hollow and enclosed, and multi-material architectures. The resulting 3D-printed green-bodies can be handled immediately, are…