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Author Baier, R.V.; Raggio, J.I.C.; Arancibia, C.T.; Bustamante, M.; Perez, L.; Burda, I.; Aiyangar, A.; Vivanco, J.F.
Title Structure-function assessment of 3D-printed porous scaffolds by a low-cost/ open source fused filament fabrication printer Type
Year 2021 Publication Materials Science & Engineering C-Materials For Biological Applications Abbreviated Journal Mater. Sci. Eng. C-Mater. Biol. Appl.
Volume 123 Issue Pages 111945
Keywords 3D printer; Scaffold; Fused filament fabrication; Mechanical properties; Finite element method; Cell adhesion efficiency
Abstract Additive manufacturing encompasses a plethora of techniques to manufacture structures from a computational model. Among them, fused filament fabrication (FFF) relies on heating thermoplastics to their fusion point and extruding the material through a nozzle in a controlled pattern. FFF is a suitable technique for tissue engineering, given that allows the fabrication of 3D-scaffolds, which are utilized for tissue regeneration purposes. The objective of this study is to assess a low-cost/open-source 3D printer (In-House), by manufacturing both solid and porous samples with relevant microarchitecture in the physiological range (100?500 ?m pore size), using an equivalent commercial counterpart for comparison. For this, compressive tests in solid and porous scaffolds manufactured in both printers were performed, comparing the results with finite element analysis (FEA) models. Additionally, a microarchitectural analysis was done in samples from both printers, comparing the measurements of both pore size and porosity to their corresponding computer-aided design (CAD) models. Moreover, a preliminary biological assessment was performed using scaffolds from our In-House printer, measuring cell adhesion efficiency. Finally, Fourier transform infrared spectroscopy ? attenuated total reflectance (FTIR?ATR) was performed to evaluate chemical changes in the material (polylactic acid) after fabrication in each printer. The results show that the In-House printer achieved generally better mechanical behavior and resolution capacity than its commercial counterpart, by comparing with their FEA and CAD models, respectively. Moreover, a preliminary biological assessment indicates the feasibility of the In-House printer to be used in tissue engineering applications. The results also show the influence of pore geometry on mechanical properties of 3D-scaffolds and demonstrate that properties such as the apparent elastic modulus (Eapp) can be controlled in 3D-printed scaffolds.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0928-4931 ISBN Medium
Area Expedition Conference
Notes WOS:000636846700007 Approved
Call Number UAI @ alexi.delcanto @ Serial 1367
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Author Martinez, C.; Aguilar, C.; Briones, E.; Guzman, D.; Zelaya, E.; Troncoso, L.; Roja, P.A.
Title Effects of Zr on the amorphization of Cu-Ni-Zr alloys prepared by mechanical alloying Type
Year 2018 Publication Journal of Alloys and Compounds Abbreviated Journal J. Alloys Compd.
Volume 765 Issue Pages 771-781
Keywords BULK METALLIC GLASSES; SOLID-SOLUTION; CRYSTALLINE; FABRICATION; EVOLUTION; POWDERS; SYSTEM; NB; TI
Abstract This work presents the effects of high energy milling with different Ni and Zr ratios on the amorphization of ternary Cu-Ni-Zr alloys (initially, Cu-43Ni-7Zr, Cu-12Ni-31Zr, Cu-33Ni-7Zr, and Cu-12Ni-23Zr; and later, Cu-23Ni-15Zr and Cu-11Ni-7Zr). Microstructure was determined using X-Ray diffraction and electron microscopy. Results were compared to thermodynamic models. In the ternary alloys under study, the lattice parameter of the Cu-Ni solid solution was generally correlated to the amounts of nickel incorporated into the Cu lattice. However, longer milling times reduced that lattice parameter and facilitated Zr insertion into the solid solution. For example, after 5 h of milling time, microstructural analysis showed the formation of a solid solution with cubic structure in Cu-43Ni-7Zr. This pattern is consistent with the presence of a lattice parameter between that of Cu and Ni (alpha-phase); in contrast, the Cu-33Ni-7Zr alloy showed an alpha-phase and another similar to Zr. Results suggest that, as the amount of nickel increases, the ability to form an amorphous phase decreases. Additionally, experimental and thermodynamic data showed a solid-solution formation stage, followed by an amorphous phase formation stage that occurred as milling time and Zr content increased. (C) 2018 Published by Elsevier B.V.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0925-8388 ISBN Medium
Area Expedition Conference
Notes WOS:000444341900095 Approved
Call Number UAI @ alexi.delcanto @ Serial 1406
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Author Varona, J.; De Fazio, R.; Velazquez, R.; Giannoccaro, N.I.; Carrasco, M.; Visconti, P.
Title MEMS-based Micro-scale Wind Turbines as Energy Harvesters of the Convective Airflows in Microelectronic Circuits Type
Year 2020 Publication International Journal Of Renewable Energy Research Abbreviated Journal Int. J. Renew. Energy. Res.
Volume 10 Issue 3 Pages 1213-1225
Keywords Energy harvesting; micro-electro-mechanical system (MEMS); micro-turbine; silicon-based fabrication process
Abstract As an alternative to conventional batteries and other energy scavenging techniques, this paper introduces the idea of using micro-turbines to extract energy from wind forces at the microscale level and to supply power to battery-less microsystems. Fundamental research efforts on the design, fabrication, and test of micro-turbines with blade lengths of just 160 μm are presented in this paper along with analytical models and preliminary experimental results. The proof-of-concept prototypes presented herein were fabricated using a standard polysilicon surface micro-machining silicon technology (PolyMUMPs) and could effectively transform the kinetic energy of the available wind into a torque that might drive an electric generator or directly power supply a micro-mechanical system. Since conventional batteries do not scale-down well to the microscale, wind micro-turbines have the potential for becoming a practical alternative power source for microsystems, as well as for extending the operating range of devices running on batteries.
Address [Varona, J.; Velazquez, R.] Univ Panamer, Fac Ingn, Aguascalientes 20290, Aguascalientes, Mexico, Email: jvarona@up.edu.mx;
Corporate Author Thesis
Publisher Int Journal Renewable Energy Research Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1309-0127 ISBN Medium
Area Expedition Conference
Notes WOS:000575124800016 Approved
Call Number UAI @ alexi.delcanto @ Serial 1249
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