3D Bioplotter Research Papers

Displaying all papers by C. Kenel (4 results)

Kinetics of alloy formation and densification in Fe-Ni-Mo microfilaments extruded from oxide- or metal-powder inks

Acta Materialia 2020 Volume 193, Pages 51-60

3D ink-extrusion of powders followed by sintering is an emerging alternative to beam-based additive manufacturing, capable of creating 3D metallic objects from 1D-extruded microfilaments. Here, in situ synchrotron X-ray diffraction and tomography are combined to study the phase evolution, alloy formation and sinter-densification of Fe-20Ni-5Mo (at.%) microfilaments. The filaments are

SnO2-Ag composites with high thermal cycling stability created by Ag infiltration of 3D ink-extruded SnO2 microlattices

Applied Materials Today 2020 Volume 21, Article 100794

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…

3D ink-extrusion additive manufacturing of CoCrFeNi high-entropy alloy micro-lattices

Nature Communications 2019 Volume 10, Article number: 904

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…

3D extruded composite thermoelectric threads for flexible energy harvesting

Nature Communications 2019 Volume 10, Article 5590

Whereas the rigid nature of standard thermoelectrics limits their use, flexible thermoelectric platforms can find much broader applications, for example, in low-power, wearable energy harvesting for internet-of-things applications. Here we realize continuous, flexible thermoelectric threads via a rapid extrusion of 3D-printable composite inks (Bi2Te3 n- or p-type micrograins within a non-conducting polymer as a binder) followed by compression through a roller-pair, and we demonstrate their applications in flexible, low-power energy harvesting. The thermoelectric power factors of these threads are enhanced up to 7 orders-of-magnitude after lateral compression, principally due to improved conductivity resulting from reduced void volume fraction and partial…