Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Feasibility study of micromilling for AISI 316L microneedles arrays(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-11-30) Tamez Tamez, Jeanette Itzel; García López, Erika; dnbsrp; School of Engineering and Sciences; Campus MonterreyMicroneedles market is expected to grow and the study of micromilling capabilities to meet medical requirements represents an opportunity of vast applications on this area. It is suggested that the limitations of this manufacturing process may lead to affect geometrical features of importance for insertion compliance. A study of the impact of the final geometric and surface features of the micromachined product on its functionality is necessary to fully understand this manufacturing technique in the medical area, especially the microdevices market. In this work, micromilling process with aid of Minimum Quantity Lubrication (MQL) system was used to manufacture AISI 316L square pyramidal (i.e., base length and height of 0.5 mm by 0.5 mm) microneedles arrays, and analysis of precision and reproducibility of measurements of height, base length, tip radius, tip angle, roughness and tool wear of ball nose micro end milling tool were performed. Based on the used cutting parameters, an optimal quantity of 30 microneedles can be manufactured to obtain values closed to those of design and guarantee insertion in skin. Simulations presented maximum radius tips of 50 microns to accomplish piercing
- Micro machinability of net shapes of Selective Laser Melting of Ti-6Al-4V for minimum material removal using ball end mill(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Celis Renata, Pavel; Vázquez Lepe, Elisa Virginia; García López, Erika; Rodríguez González, Ciro Ángel; Sandoval Robles, Jesús A.Miniaturization of medical devices is playing an important role in the manufacture industry. New drug delivery systems are being studied and developed, therefore materials to produce these devices must be investigated extensively. The objective of this work is to experimentally investigate and compare the machinability of Ti-6Al-4V titanium alloy produced via Selective laser melting (SLM) against the conventional machining method. 18 patches of 09 needles each were fabricated and machined with different cutting feeds (120,150 and 180mm/min) with aid of a minimum quantity lubrication (MQL) system. Machinability was examined in terms of cutting forces, tool wear, surface roughness and geometrical dimensions. Each cutting feed was tested by fabricating 3 patches from solid blocks of titanium with square tools of .8mm. Finish pass was performed with a .2mm micro ball end mill with a constant spiral toolpath. Comparison was performed by fabricating four patches with SLM with an excess material of 150μm and machined with the same previous parameters. 3D images obtained by optical microscope reveal that the main force applied in the finishing of needles is the Z axis and cutting forces were higher when machining SLM patches. Tool calibration is the main factor to obtain high precision in geometrical dimensions due to the variation in length because of thermal expansion. Surface roughness for all tests were below 1μm with best results when cutting feed is set at 120mm/min, reduction in edge radius for ball end mills affected negatively the surface roughness. An economic comparison was performed and showed that the SLM combined with SM process has clear advantage over subtractive manufacture alone.