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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- Centrifugal microfluidic platform for applications in low-concentration biosensing of E. Coli(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-11) Farías Álvarez, Mario Alfredo; Madadelahi, Masoud; emimmayorquin, emipsanchez; Salinas Salazar, Carmen Lizzeth; Pilloni Choreño, Oscar; School of Engineering and Sciences; Campus MonterreyAccess to clean and drinkable water is not yet a possibility in many parts of the world. In different regions or rural areas where common water sources are prone to contamination or places where the water treatment does not follow a strict and efficient protocol for disinfection and purification, different pathogens can end up being consumed by several people. Water in these and other places can be contaminated with relative ease, potentially facing from hundreds to thousands of deaths all around the world from diseases caused by unsafe water treatment and pathogenic bacteria. The bacteria Escherichia Coli O157:H7 is a highly pathogenic bacteria that causes a series of gastrointestinal complications and diseases. If left untreated, the consequences can be fatal. Because of this, the need for early detection of this pathogen in water supplies is of great importance. Aptamers are single-stranded chains of DNA or RNA whose sequence can be designed to fold into specific shapes. They can act as an alternative to antibodies for the recognition and binding to antigens and targets of interest. Aptamers have been studied for this potential, and have been successfully synthesized to bind to components in the outer cell membrane of pathogenic bacteria, allowing for a high selectivity. Dendrimers are poly-branched polymers that have the advantage of being able to grow to various generations, exponentially increasing the number of branches they have. Polyamidoamine dendrimers have been studied and researched for their potential in biomedical applications. The functional groups of the branches can be modified and have attached a functional group with the purpose of integrating them into sensing devices. The multiple branches of polyamidoamine dendrimers can then serve as multiple attachment sites for aptamer placement, increasing the amount of bacteria-capturing agents on a biosensing surface. Flow reciprocation is a concept that has been introduced in microfluidic devices, and consists in driving the fluid either actively or passively through a a microfluidic circuit in two directions. This can allow the fluid sample to return to the source or point of origin in the microfluidic device. This concept can be present in centrifugal microfluidics, in which passive ways of reciprocation have been implemented successfully. Pneumatic chambers have been used in order to achieve flow reciprocation by compressing air during the rotation of the device and expanding it during its deceleration. The compression of air is caused by the fluid entering the pneumatic chamber, and it returns to the source chamber due to the air expansion. Since this technique requires high rotational velocities, an alternative is to use flexible membranes as passive pumps that inflate upon rotation and relax during deceleration. These membranes allow for lower rotational speeds and the potential of ease of reciprocation. Flow reciprocation can then be used in biosensors to increase the interaction between the target and the biosensing surface. Then, this can be applied to increase the capturing of pathogenic bacteria by combining this concept with aptamers and dendrimers to achieve low limits of detection. Trial and error of microfluidic devices designs often leads to unused devices that end up discarded and in the trash, which translates into material going to waste. In order to optimize the design and save fabrication resources, computational simulations can be of use. By modeling the desired microfluidic device, one can change any relevant parameters before the actual fabrication of the final device. Lumped-element models are representations of a microfluidic circuit in which each component is governed by its own set of equations and global, system-wide variables are transmitted through ports, obeying Kirchhoff’s laws. The present work aims to combine all of these concepts into a centrifugal microfluidic device for the detection of Escherichia Coli O157:H7 pathogenic bacteria, utilizing aptamers attached to polyamidoamine dendrimers to have multiple capturing sites and using flow reciprocation to enhance the interaction between the bacteria and the aptamers for increased capturing. Fur- thermore, it aims to further develop a lumped-element model for the simulation of centrifugal microfluidic devices, incorporating a new component with elastic membranes for the purpose of flow reciprocation. A limit of detection of 8.137 × 103 CFU/mL was achieved.
- Design and fabrication of a microfluidic device for the dielectrophoretic trapping of microparticles using carbon nanofibers(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-13) López Esparza, Tania Jaqueline; Salazar Soto, Arnoldo; emimmayorquin; Gallo Villanueva, Roberto Carlos; Sierra Valdez, Francisco Javier; School of Engineering and Sciences; Campus Monterrey; Perez González, Victor HugoMicroparticle manipulation is an important subject to study; it can be used for the separation of complex mixtures, with applications in environmental pollutant analysis or disease detection. Conventional microparticle separation methods are mostly based on size or molecular weight, leading to reduced purity of the obtained sample. Electromechanical interaction of microparticles has been studied for their manipulation since it offers more selective and efficient results than conventional methods. In this work, a microfluidic device was designed, aimed for its future potential application for trapping of exosomes using dielectrophoresis force using a glassy carbon microfiber as the electrode. A computational model of the device was analyzed to demonstrate an increase in the magnitude of the gradient of the squared electric field created between the fiber and its counter-electrode, reaching values up to 1×10¹⁸ V2/m3. Likewise, functional initial prototypes of the designed device were fabricated, which were used in starting experiments to demonstrate dielectrophoretic trapping of microparticles using PS microbeads with positive dielectrophoresis.
- Development of a multi-component disjointed tissue culture system using three-dimensionally printed polymeric scaffolds and microfluidic pumping(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12) Romero Zepeda, Claudia Alejandra; Lozano Sánchez, Luis Marcelo; emipsanchez; Perfecto Avalos, Yacanxóchitl; García González, Alejandro; García Varela, Rebeca; School of Engineering and Sciences; Campus León; Chaires Oria, Jorge IsaacIn-vitro cellular culture plays a crucial role in preclinical research. While cost-effective, the pre- vailing 2D culture approach falls short in simulating realistic cellular interactions when these cells are grown in different but interacting spaces. Organs-on-a-Chip (OoC) devices have been developed to address this limitation, creating controlled micro-environments that mimic in-vivo tissue interaction conditions. This research addressed designing and assessing a microfluidic chip device based on ad- ditive manufacturing to analyze fibroblast and monocyte cell interaction grown in a separate culture apparatus. The OoC devices were created using Computer-Aided Design (CAD), and additive manu- facturing strategies using translucent resin as constructive material. The developed chip consisted of 200 mm2 cell culture area, a glass window for monitoring, and two inlets and outlets for fluid transfer and sampling. An instrumented peristaltic micro-pumping system induces fluid motion through the tubing that connects the manufactured microchips. Here, we show the ability of the developed 3D printed system to culture different cell lines, allow treatment addition without disturbing the system, and connect with a continuous flow between the devices without generating detectable cellular stress by enzymatic quantification. Finally, the interconnected system communicates between fibroblast and monocyte cultures by connecting two chips with micropumps through microscopic and cellular stress markers in selected cell lines. This results in a prototype for a multi-organ-on-a-chip-like device.
- 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.
- 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.
- Optical flow sensor for droplet-based Lab-on-PCB devices(Instituto Tecnológico y de Estudios Superiores de Monterrey) Solano Teran, Daniel Hugo; CAMACHO LEON, SERGIO; 213140; Camacho León, Sergio; puelquio, emipsanchez; Luque Estepa, Antonio; Vázquez Piñón, Matías; Escuela de Ingeniería y Ciencias; Campus MonterreyAdvancements on Lab-on-a-PCB devices nowadays focus on design goals such as Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free, Deliverable to end-users (ASSURED) devices. However, most of these new systems present external equipment dependencies, complex set-up processes, low reproducibility factors, and intricate manufacturing processes. For many industries (medical, pharmaceutical, cosmetics), Lab-on-a-PCB devices are capable of characterizing multiphase systems such as cell-in-droplets identification, flow-phase characterization, and micromixing detection. Thus, this work presents a new optical droplet detector, employing common and cost-effective electronics components. The device consists of a fluid channel between a light-emitting diode (LED) and a photo-resistor (LDR), whose voltage variation is measured and then processed with an ARDUINO microcontroller. This new sensor can determine different multiphase flow properties such as velocity, flow, droplet lengths, and volume with high-speed throughput up to 1000 droplets per second. Furthermore, this sensor presents a modular electronic design that provides a simple calibration, high adaptability, and a standardized fabrication process. Therefore, it creates a cost-effective, portable, easy-to-fabricate, and plug-and-play environment for the alignment with the ASSURED criteria. Droplet detection and characterization showed MRE values ranging from 2.4% up to 17%. The lowest MRE value was obtained using a two-phase flow system with water-in-air droplets at a sampling rate of 2.3 kHz for flow rates starting at 20 up to 425 μL/min. In contrast, the highest MRE value reported was under a three-phase flow system for dyed and pure water-in-air droplets at a 5 kHz sampling rate at a 250 µL/min flow rate.