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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- On the effect of insulator structures in electrokinetically driven microfluidic devices(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025) Martínez González, Vania Guadalupe; Pérez González, Víctor Hugo; emimmayorquin, emipsanchez; Martínez López, José Israel; Roberts Ugrinovic, Ricardo Esteban; Gallo Villanueva, Roberto Carlos; School of Engineering and Sciences; Campus MonterreyWithin insulator based electrokinetically driven microfluidic devices (iEK, or iDEP) field, it is worth predicting the distribution of the electric field that a specific microchannel will have when voltage is applied. The electric field distortion is provoked by the presence of insulator pillars arranged in certain dispositions with the aim of manipulating particles (for instance, polystyrene beads, bacteria, cells, exosomes, etc.). Commonly, researchers simulate microchannel geometry in a finite element method (FEM) based software. Despite accurateness, this approach is costly and time consuming; this creates delays in the design process. This work provides an easy use analytical model based on electric circuit theory. The present tool calculates voltage and electric field profiles along a centered cut line throughout a microchannel. The circuit model was validated using FEM-based software and applied to an experimental case. Experimental case was an effort of reducing voltage requirement to achieve particle trapping. For that purpose, three designs of direct current insulator based electrokinetically driven (DC-iEK) microfluidic devices were used. The target geometries were two triangles forming a single constriction. Devices were stimulated using 9 V alkaline batteries and tested with 2 µm fluorescent polystyrene particles. The minimum voltage at which particle trapping was observed was 18 V.
- DC-Voltage reduction for electrokinetic particle trapping in PDMS-based microfluidics(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-11-29) Ramírez Murillo, Cinthia Janet; Pérez González, Víctor Hugo; 349700; Pérez González, Víctor Hugo; puelquio/mscuervo; Gallo Villanueva, Roberto Carlos; Trujillo de Santiago, Grissel; Escuela de Ingeniería y Ciencias; Campus MonterreyThe objective of this work is to reduce the voltage requirement for particle manipulation and trapping in an insulator-based microfluidic channel. Insulator-based microfluidic devices have been used in the past for particle analysis, separation, and concentration. Although some efforts have been successfully carried out to manipulate particles in microfluidic channels of this type, the electric fields required for particle movement and trapping are generally higher than 100 V cm-1, limiting the possibility of creating an integrated, portable device that is suitable for point-of-care applications. Starting with a two-post geometry for the insulating feature in our channel, we amplify the electric field at the center of the channel through dimensional optimization of the constriction and the post diameter, lowering the voltage required to be applied across the channel in order to achieve particle displacement and trapping. The present work includes the fabrication and experimental trapping results obtained in the channel designs produced after a modelling and optimization process to select the most efficient geometries to be created.
- Geometry optimization and prediction of voltage requirements for particle trapping in EK-driven insulator-based microfluidics(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-11) De los Santos Ramírez, Jesús Martín; DE LOS SANTOS RAMIREZ, JESUS MARTIN;;3167697; Pérez González, Víctor Hugo; puelquio, emipsanchez; Gallo Villanueva, Roberto Carlos; Moises Alvarez, Mario; School of Engineering and Sciences; Campus MonterreyElectrokinetically-driven microfluidics devices have shown to be of great interest for researchers especially when applied in biomedical engineering, medical diagnosis, and biological research. A growing field for this technology is the development of Point-of-Care devices, due to their capability to offer portable, fully integrated, easy to use, and low-cost diagnostic platforms. This work presents an analysis of current electrokinetically-driven (i.e., dielectrophoresis, electrophoresis, electroosmosis) devices from the point of view of voltage requirements, especially for insulator-based devices which are characterized by high (hundreds to thousands of volts) input voltages. Moreover, this work addresses the high voltage problem by presenting a geometry optimization methodology, based on recent advances in the area, to reduce and predict the voltage requirements in insulator-based devices.
- A C-MEMS based electroosmotic microreactor for anisotropic AuNPs synthesis: Proof of concept(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-05-28) Ortiz Castillo, José Eric; ORTIZ CASTILLO, JOSE ERIC; 885252; Pérez González, Víctor Hugo; ilquio; Martinez Chapa, Sergio Omar; Gallo Villanueva, Roberto Carlos; School of Engineering and Sciences; Campus MonterreyAnisotropic gold nanoparticle synthesis has aroused great attention in the scientific community in the last two decades. These nanomaterials have unique properties that make them suitable for a wide range of applications in the biomedical field such as optical sensing, biomedicine, chemical catalysis, etc. Therefore, there have been several efforts in the seek of novel and green synthetic methodologies for gold nanoparticles. The control of the concentration of reactants and the kinetics of the reaction are two crucial parameters for the developing of a good synthetic procedure. Microfluidics offers different approaches to deal with the materials synthesis at a microscale with a higher synthetic control at a molecular level. A proof of concept for the synthesis of anisotropic gold nanoparticles was carried on a C-MEMS based electroosmotic microreactor. This microfluidic design was used previously specifically as a bidirectional electroosmotic flow micropump. The velocity profile produced by this microfluidic device was employed to mix the reaction components for the chemical synthesis of anisotropic gold nanoparticles. The reactor was studied with an experimental design and computational modelling. Finally, the anisotropic gold nanoparticles were characterized by UV-Vis and TEM microscopy.