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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- Simulation of a centrifugal microfluidic device for particle separation through acoustophoresis(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-08-02) Rubio Téllez, Montserrat; MARTINEZ CHAPA, SERGIO OMAR; 31803; Martínez Chapa, Sergio Omar; emipsanchez; Ray, Mallar; School of Engineering and Sciences; Campus Monterrey; Madadelahi, MasoudParticle and cell separation is a fundamental operation in biomedical research and clinical diagnostics. Circulating tumor cells (CTCs) separation is gaining interest because its detection and further study can help in early cancer diagnosis or provide guidance in chemotherapy treatment. Acoustophoresis in microfluidic devices has the potential to separate CTCs and rare cells from blood samples. This technology manipulates particles with acoustic waves and is a contact-free, label-free and highly sensitive technique. There has not been any experimental or computational study integrating acoustophoresis in centrifugal microfluidic platforms. This work presents the proof of concept of both principles for particle and cell separation, through the simulation of the device. A 3D FEM-based model was built in COMSOL for predicting the particles path. The geometry consisted first in a Surface Acoustic Wave based device with 2 pairs of IDTs located on top of a piezoelectric substrate, with a rectangular fluid channel with three inlets and three outlets. By applying boundary conditions, input parameters, and considering centrifugal, Coriolis, drag, lift and acoustic radiation forces; the particle’s paths are obtained. An attempt to validate the model with a previous experimental work was not successful since the acoustic pressure field was not generated correctly. However, the model was validated with a previous published simulation work of a non-centrifugal platform, and then used for computational demonstration of acoustophoretic separation of CTCs from white blood cells and red blood cells. A parametric analysis was performed to study the influence of five parameters on the efficiency of the device. Results showed that the recovery rate of CTCs at the center-outlet decreases when the angular velocity increases, when the distance to the axis of rotation increases, and when the distance between the IDTs and the channel increases. Recovery rate of CTCs at the center-outlet increases when voltage increases. Centrifugal platforms were found to be more sensitive to density variations. The model was modified to simulate a Bulk Acoustic Wave-based device and an attempt to validate it with a previous experimental work was done, however limitations were found. This work provides an understanding of the behavior of a centrifugal microfluidic platform with acoustophoresis and might be used as the initial reference for future computational work for correctly generating the acoustic pressure field and subsequently future experimental studies of particle and cell separation.
- Diseño de microespejo CMOS de barrido resonante para sistemas endoscópicos de tomografía óptica(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2006-05-01) Camacho León, Sergio; CAMACHO LEON, SERGIO; 213140; Martínez Chapa, Sergio Omar; Elías Zúñiga, Alex; Gutiérrez Vega, Julio César; Programa de Graduados en Tecnologías de Información y Electrónica; Campus Monterrey; Garza Salazar, DavidEn este trabajo se presenta el diseño y la modelación de un microescaner de barrido resonante para sistemas de imagenología biomédica con énfasis en aplicaciones endoscópicas. El dispositivo óptico diseñado consiste en una lente de campo plano y un espejo microelectromecánico con 22,032 µm2 de superficie. El microespejo es impulsado por seis de actuadores térmicos bimorfos, cada uno con 200 µm de longitud y 18 µm de ancho. Los parámetros estructurales y geométricos del microespejo fueron diseñados para ser compatibles con las reglas de diseño de la tecnología CMOS de 0.6 µm. Las características de enfoque y exploración de este dispositivo permiten su aplicación en sistemas endoscópicos de tomografía óptica para realizar los barridos transversales del haz láser en el tejido biológico en estudio. Para modelar el microespejo se utilizó la teoría clásica de Euler-Bernoulli y se obtuvieron las ecuaciones matemáticas que determinan la dependencia de su comportamiento estático y dinámico con las dimensiones y las propiedades físicas de los materiales empleados en su fabricación. A partir de los modelos obtenidos, se optimizó el proceso de diseño de manera que es posible minimizar el consumo de potencia de los actuadores térmicos y se propuso utilizar el nodo estacionario del segundo modo de vibración como un eje de rotación adicional sin translación para incrementar el ángulo de deflexión y la velocidad de exploración. Los resultados obtenidos en los modelos analíticos, para la deformación termomecánica generada por el efecto Joule así como para los modos naturales de vibración, concuerdan con las simulaciones realizadas por métodos de elementos finitos y demuestran que el desempeño del microespejo es superior en comparación con otros diseños reportados en publicaciones previas.
- Development of a tunable and resealable porous membrane for organ-on-a-chip devices(Instituto Tecnológico y de Estudios Superiores de Monterrey) Corral Nájera, Kendra; MARTINEZ CHAPA, SERGIO OMAR; 31803; Martínez Chapa, Sergio Omar; tolmquevedo, emipsanchez; Gallo Villanueva, Roberto Carlos; School of Engineering and Sciences; Campus Monterrey; Aeinehvand, MohammadMahdiOrgan-on-a-chip platforms are a promising technology for research in biotechnology, tissue engineering and pharmaceutical fields. They enable the study of physiological processes, facilitating the development of new drugs and broadening the understanding of the effects of mechanical and chemical cues in different cell lines. A very crucial role in these devices is played by porous membranes, which separate chamber content while allowing substance exchange through micro or nano pores. Additionally, it is the membrane that supports the cell culture and may provide actuation. Available porous membranes however do not possess resealability nor tunability features. This thesis presents a comprehensive review of organ-on-a-chip applications and the role of porous membranes within them, as well as membrane actuation methods and fabrication techniques. It also demonstrates the development of novel tunable and resealable porous PDMS membranes of different thicknesses, fabricated using fast and inexpensive prototyping methods for their integration into microfluidic plastic chips. Membrane deformation and pore opening were studied as a function of liquid flow rate. Pore opening increased with higher flow rates, demonstrating the tunability of pore opening useful for toxicological or pharmacological applications that require controlled transfer of substances or particles between chambers. The proof-of-concept study of a tunable and resealable porous membrane presented in this thesis is expected to motivate future works in smart membranes embedded in organ-on-a-chip devices to increase the system’s representativity and better emulate organs in vitro.