Biomedical Devices and Instrumentation Commons^™

Evaluation Of Antibiotic Testing Protocols For Biofilm-Forming Escherichia Coli In A Microfluidic Platform, Caleb R. Telander

Master's Theses

Catheter-associated urinary tract infections remain an ongoing clinical problem due to biofilm persistence and antibiotic resistance. Standard antibiotic susceptibility testing cannot accurately reproduce flow conditions and the spatial complexity of the in vivoenvironment and is thus questionable in relevance to device-related infections. This study examines a microfluidic device designed to simulate physiologically relevant wall shear stress and antibiotic gradients in Escherichia coli biofilms. The polydimethylsiloxane-based system integrates a 16-well culture chamber with a gradient generator. Biofilm growth was observed using fluorescence microscopy of green fluorescent protein-labeled bacteria. Simulations performed using COMSOL Multiphysics software estimated the appropriate range of wall …

Development Of Translational Microscale Systems To Interrogate How Biophysical And Biochemical Cues Alter The Phenotype Of Hormone Positive Breast Cancer, Braulio Ortega Quesada

All Dissertations

Cancer is a complicated disease and one in every three diagnoses are women with breast cancer. Recent research shows that the progression of cancer depends strongly on interactions with other non-cancerous cells and non-cellular components. Metastasis, the spread of cancer to other parts of the body, is a key step in cancer progression and makes treatment harder, leading to poor response to treatments culminating in death in ~90% of patients. This dissertation focused on creating a series of microdevices as novel pre-clinical models of breast cancer. Two different devices were fabricated to (1) study how exposing cancer cells to the …

In Vitro Microfluidics System For Mechanobiologic Investigations, Michael A. Daanen

Honors Theses

Mechanobiology is an emerging field that aims to study the relationships between mechanical forces and cellular behavior. Such mechanobiological relationships are especially critical in the cardiovascular system, where endothelial cells lining the vasculature align in response to fluid shear stresses from blood flow (Sinha, 2016). Implanted flow devices, diabetes, chronic hypertension, and various other diseases and pathophysiologies alter vessel geometries and flow dynamics. Such alterations impact fluid shear stress and endothelial cell behavior, leading to microcirculatory dysfunction, vessel leakage, and organ failure (Poredos, 2021; Papadaki, 1999; Leitschuh, 1987). To simulate dysfunctional endothelial cell behavior in vitro and evaluate novel therapeutic …

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

Patterned Magnetic And Plasmonic Nanostructures In Microfluidics For Extracellular Vesicle Screening And Drug Loading, John H. Molinski

Dartmouth College Ph.D Dissertations

Extracellular vesicles (EVs), once dismissed as shuttles for cellular waste, have emerged as vital nanoscale biomolecules, facilitating intercellular communication through transfer of host-cell specific molecular cargo. Tumor-derived EVs, released by cancer cells, hold potential as diagnostic biomolecules due to their links to cancer cells, abundance within biofluids, and potential for direct extraction and detection. More broadly, EVs from a wide array of cellular origins have been explored as therapeutic carriers, stemming from their innate function as cargo carriers, high biocompatibility, and their ability to evade immune detection. However, harnessing EVs for diagnostic or therapeutic applications necessitates efficient isolation, purification, and …

Novel Microfluidic Devices To Model The Interactions Between Lymphatics And Breast Cancer, Jade Weber

McKelvey School of Engineering Graduate Student Theses & Dissertations

The lymphatic system is responsible for immune circulation and fluid balance in the body. It accomplishes this by draining interstitial fluid from local tissue and transferring it to lymph nodes and back into blood circulation. However, this process is implicated in many pathologies, one of the most dangerous being breast cancer metastasis to the lymph nodes. The largest factor in breast cancer patient mortality is metastasis. Lymphangiogenesis, the growth of new lymphatic vessels, has been thought to play a dynamic role in aiding breast cancer metastasis. Breast cancer tumor cells have been shown to remodel the functionality of local lymph …

Synthesis Of Thiol-Acrylate Hydrogels For 3d Cell Culture And Microfluidic Applications, Anowar Hossain Khan

LSU Doctoral Dissertations

Globally cell culture is an $18.98 billion industry as of 2020, with an 11.6 percent annual growth rate. Drug discovery has an estimated worth of $69.8 billion in 2020 and is predicted to grow to $110.4 billion by 2025. Three-dimensional (3D) cell culture of cancer cells is one of the rapidly growing felids since it better recapitulates in vivo conditions compared to two-dimensional (2D) models. However, it is challenging to grow 3D tumor spheroids outside the body, and some of the existing technology can generate these spheroids outside the human body but poorly mimic in vivo tumor models. Therefore, there …

An Electrochemical, Fluidic, Chip-Based Biosensor For Biomarker Detection, Lauren Bell

Theses and Dissertations--Biomedical Engineering

Biosensors and their use in both the research and clinical field for the detection and monitoring of critical biomarkers are prevalent and constantly improving. However, continued research needs to be done to address shortcomings, such as low sensitivity, poor specificity, and poor readiness for integration into research use and patient care. The objective of this research was to create a combined fluidic, chip-based biosensor that could detect different biomarkers with high sensitivity and ease of use. For assessing the developed sensor, three separate biomarkers were tested: glucose, cholesterol, and oxygen. Both the glucose biosensor and cholesterol biosensor were combined with …

Nano-, Encapsulated Manganese Oxide (Nemo) Particles For Mri Enhancement In Microfluidic Tumor Models, Kasey Alexis Freshwater

Graduate Theses, Dissertations, and Problem Reports (ETD)

Breast cancer is among the deadliest cancers in women, with approximately 2.3 million new cases and 685,000 deaths reported globally in 2020 alone. Magnetic Resonance Imaging (MRI) is commonly used to diagnose, stage, and develop treatment plans for patients predisposed to breast cancer. However, current MRI-based screening of breast cancer has high false-positive rates up to 25%, leading to unnecessary invasive follow-up screening and testing. The gold-standard intravenous gadolinium (Gd)-based contrast agents (GBCAs) account for false-positive rates because they are always “ON”, providing a constant MRI signal that highlights both benign and malignant tumors. The work detailed in this thesis …

Development Of A Microfluidic Viscoelastic Hemostatic Assay For Real-Timeviscosity Measurements Of Blood, Shay Kent

Electronic Theses and Dissertations

Blood coagulation disorders are malfunctions in the body’s ability to control blood clotting. It can result in either insufficient clotting causing an increased risk of bleeding or excessive clotting obstructing blood flow. The rapid and accurate diagnosis of coagulopathies is an important, unmet need in the clinical setting. Rapidly identifying the source of bleeding, either acquired or inherited, is critical to reduce the risk of major blood loss and deliver personalized hemostatic therapies. Viscoelastic hemostatic assays, or VHAs, deliver an effective solution to the diagnosis of coagulopathies by evaluating global hemostatic function using whole blood rather than plasma. VHAs are …

Microfluidic Electrical Impedance Spectroscopy System Automation And Characterization, Keaton Frahmann

Master's Theses

In this work, a novel microfluidic cell culture platform capable of automated electrical impedance measurements and immunofluorescence and brightfield microscopy was developed for further in-vitro cellular research intended to optimize cell culture conditions. The microfluidic system design, fabrication, automation, and design verification testing are described. Electrical and optical measurements of the 16 parallel cell culture chambers were automated via a custom LabView interface. A proposed design change will enable gas diffusion, removing the need for an environmental enclosure and allow long-term cell culture experiments. This "lab on a chip" system miniaturizes and automates experiments improving testing throughput and accuracy while …

Isomotive Dielectrophoresis For Enhanced Analyses Of Cell Subpopulations., Mohamed Zakarya Rashed

Electronic Theses and Dissertations

As the relentless dream of creating a true lab-on-a-chip device is closer to realization than ever before, which will be enabled through efficient and reliable sample characterization systems. Dielectrophoresis (DEP) is a term used to describe the motion of dielectric particles/ cells, by means of a non-uniform electric field (AC or DC). Cells of different dielectric properties (i.e., size, interior properties, and membrane properties) will act differently under the influence of dielectrophoretic force. Therefore, DEP can be used as a powerful, robust, and flexible tool for cellular manipulation, separation, characterization, and patterning. However, most recent DEP applications focus on …

Primer Payload System For Higher-Order Multiplex Lamp: Design And Development Of Unit Processes, Tochukwu Dubem Anyaduba

KGI Theses and Dissertations

Design and Development of Platforms for the Application of Loop-mediated Isothermal Nucleic Acid Amplification, LAMP, in the Diagnosis of Polymicrobial Diseases

Tochukwu Dubem Anyaduba, Travis Schlappi (PI)

For the past two decades, several isothermal nucleic acid amplification technologies have emerged. These are mostly in response to the need for robust molecular diagnostic tools amenable to point-of-care and limited-resource settings. Of these, loop-mediated isothermal amplification, LAMP, stands out as a highly specific and rapid alternative to the polymerase chain reaction, PCR. One of LAMP's significant characteristics involves using four essential and two loop (rate increasing) primers to recognize six to eight …

Opendrop Elisa: Surface Development For Digital Microfluidic Elisa Testing, Michaela Q. Mead, Madeline G. Jackson, Jacob G. Taylor

Biomedical Engineering

This project aimed to develop a process to create a hydrophobic coating with capture antibodies attached. This process was developed in an attempt to create a digital microfluidic platform upon which an enzyme-linked immunosorbent assay (ELISA) could be run, indicated for clinicians and educators in low-resource settings. Four requirements dictated the course of the design process: 1) the contact angle with water of the hydrophobic layer must be greater than 90º, 2) the colorimetric response of a positive ELISA result on our platform must be at least 85% of that run on polystyrene with the same result, 3) the platform …

Insulative (Direct Current) Dielectrophoretic Foul-Less Filtration In Microfuidic Systems, Matthew A A Whitman

Master's Theses

Filtration is a technology that is used almost ubiquitously in society from uses raging from filtration of macroparticles from water to pharmaceutical grade filtration products to remove anything larger than a protein. However, with such a wide range of uses, most filtration products have the same issue; membrane clogging (fouling) that prevents continuous use and requires frequent maintenance. This thesis hypothesizes that by applying a direct current (DC) to an insulating array of posts, they will create a foul-less insulative dielectrophoretic filter (iDEP) that does not clog since particles will levitate above the insulating array.

This thesis tested an inherited …

Modification And Optimization Of Conducting Polymer-Modified, Redox-Magnetohydrodynamics (R-Mhd) Pumping For Enhanced And Sustained Microfluidics Applications, Md Foysal Zahid Khan

Graduate Theses and Dissertations

In this work, a novel microfluidic pumping approach, redox-magnetohydrodynamics (R-MHD) has improved by materials and device optimization to use in lab-on-a-chip applications. In R-MHD, magnetic flux (B) and ionic current density (j) interacts to generate body force (FB) in between active electrodes, according to the equation FB = j×B. This unique fluid pumping approach is scalable, tunable, generates flat flow profile, and does not require any channels or valves. Pumping performance, such as speed scales with the ionic current density (j) and duration depends on the total charge (Q). The ionic current density (j) results from the conversion of electronic …

Fluid Delivery System For A Cell Culture On A Microfluidic Chip, Austin J. Roeder, Colleen A. Richards, Emily A. Matteson

Biomedical Engineering

This project report provides a description of the progress made in the development of a fluid delivery system for a microfluidic cell culture on a chip. The system is intended to be used in a humidified incubator in a university laboratory and the fluid delivery system is required to exist and operate within that incubator for extended periods of time. Therefore, the system will be gravity-driven and contain no electronic components. The key specification of the system is to provide fluid flow at a constant velocity.

After manufacturing and testing the device, all specifications were met except for the fluid …

Acoustofluidics And Soft Materials Interfaces For Biomedical Applications, Frank A. Fencl

Biomedical Engineering ETDs

This dissertation describes fabrication of devices and other tools for biomedical applications through the integration of acoustofluidic systems with bio separation assays, instrumentation components, and soft materials interfaces. For example, we engineer a new class of transparent acoustic flow chambers ideal for optical interrogation. We demonstrate efficacy of these devices by enhancing the signal for high throughput acoustic flow cytometry, capable of robust particle focusing across multiple parallel flowing streams. We also investigate an automated sampling system to determine the parameters of transient particle stream focusing in between sample boluses and air bubbles to model a high throughput, multi-sampling acoustic …

Microfluidic Electrical Impedance Spectroscopy, John J. Foley

Master's Theses

The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were …

Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline Alexandria De Lora

Biomedical Sciences ETDs

Adaptation of cancer cells to changes in the biochemical microenvironment in an expanding tumor mass is a crucial aspect of malignant progression, tumor metabolism, and drug efficacy. In vitro, it is challenging to mimic the evolution of biochemical gradients and the cellular heterogeneity that characterizes cancer tissues found in vivo. It is well accepted that more realistic and controllable in vitro 3D model systems are required to improve the overall cancer research paradigm and thus improve on the translation of results, but multidisciplinary approaches are needed for these advances. This work develops such approaches and demonstrates that new droplet-based cell-encapsulation …

Microfluidic Technology And Application In Urinal Analysis, Jiwen Xiang

LSU Doctoral Dissertations

Microfluidic technology offers numerous advantages in minimizing and integrating the traditional assays. However, the lack of efficient control components of the microfluidic systems has been hindering the widely commercialization of the technology. The research work in this dissertation focused on the development of effective control components for microfluidic applications.

A linear peristaltic pump was firstly designed, fabricated, and tested for conventional microfluidics by synchronously compressing the microfluidic channel with a miniature cam-follower system in Chapter 2. The miniature cam-follower system and microfluidic chip was prototyped using three-dimensional (3D) printing technology and soft lithography technology. Results from experimental test showed that …

Collective Chemotaxis Of Retinal Neural Cells From Drosophila Melanogaster In Controlled Microenvironments, Stephanie Zhang

Dissertations and Theses

More than 172 million people are influenced by a retinal disorder that stems from either age-related or developmental causes. Of those, 1.5 million people endure a developmental retinal disorder. In the developing retina, neural cells undergo a series of highly complicated differentiation and migration process. A main cause of these diseases is abnormal collective migration of neural progenitors hindering the retinogenesis process. However, our grasp of collective migration and signaling molecules, critical to the developing retina, is incompletely understood. Understanding the molecular mechanisms, such as the fibroblast growth factor pathway, that regulate glial and neuronal migration provides decisive insights in …

Poly Drop, Zachary T. Scott, Lilly J. Paul

Computer Engineering

Poly Drop is a software interface to control an Open Drop digital micro-fluidics system. We obtained a hardware system from Gaudi labs. Our task was to create a Graphical User Interface that made the control of the device easier and more automated for better testing. We created software that had 3 parts: a control GUI, arduino code to control the hardware, and Image Analysis that gives the user information such as location and color of liquid drops as they move across the electrode grid of the Open Drop system. The GUI was developed using Java Swing. The communication between the …

Shear Driven Micro-Fluidic Pump For Cardiovascular Applications, Nihad E. Daidzic

Aviation Department Publications

A valveless shear-driven micro-fluidic pump design (SDMFP) for hemodynamic applications is presented in this work. One of the possible medical and biomedical applications is in-vivo hemodynamic (human blood circulation) support/assist. One or more SDMFPs can be inserted/implanted into vascular lumens in a form of a stent/duct in series and/or in parallel (bypass duct) to support blood circulation in-vivo. A comprehensive review of various micro-pump designs up to about mid 2000’s is given in [1,2]. Many of micropump designs considered are not suitable for in-vivo or even in-vitro medical/biomedical applications.

Operating principles, design, and SDMFP features are given in [3]. A …

A Microfluidic-Based Tactile Sensor For Palpating Mice Tumor Tissues, Yichao Yang, Garett Johnson, Dean Krusienski, Siqi Guo, Cheng Lin, Zhili Hao

Mechanical & Aerospace Engineering Faculty Publications

In light of the need of tissue palpation for Robotics-assisted Minimally Invasive Surgery (RMIS), this paper presents a microfluidic-based tactile sensor for palpating mice tissues for tumor localization. The core of the sensor is a 3x3 sensing-plate/transducer array built into a single polydimethylsiloxane (PDMS) microstructure, with a transducer spacing of 3.75mmx1.5mm. Mounted on a robot, the sensor is pressed against a tissue region with a pre-defined indentation depth pattern, and consequently the stiffness distribution across the tissue region translates to the deflection distribution of the sensing-plate array and is captured by the transducer array underneath as resistance changes. Thus, the …

Quantification Of Analyte Concentration From A Paper-Based Lateral Flow Assay Device Using Reflective Sensors, Megan Z. Chiu, Jacqueline Linnes

The Summer Undergraduate Research Fellowship (SURF) Symposium

Paper-based point-of-care (POC) diagnostics is a growing field in global health due to the extreme portability, accuracy, affordability, and ease of use of these tests. Advancements in recent years have led to more accurate detection and improved functionality using multistep molecular diagnostics. Many such assays utilize lateral flow detection strips for visualization of diagnostic results by eye, which limits the results to qualitative Yes/No readouts. This project focused on combining recent developments in paper-based POC diagnostics to develop and optimize an in-house built quantitative paper-based diagnostic reader for lateral flow detection in low-resource settings. Initially different sensors, including photocell sensors, …

Nasa Limited Inflight Lab Sensor, Gregory P. Howard, James C. Hanreck

Williams Honors College, Honors Research Projects

The National Aeronautics and Space Administration (NASA) is currently developing the capabilities needed to send humans to Mars in 2030 for a three year mission. Astronaut health must be monitored monthly during such a lengthy mission. The UA Enterprise Senior Design Team worked to design a reusable, novel blood panel cartridge system to monitor astronaut health and to minimize waste production. Most current cartridges are composed of polydimethylsiloxane (PDMS). PDMS microchannels were fabricated to conduct simple proof of concept experiments for the design of a novel cartridge. To determine an ideal blood cleaning solution, bovine blood will be injected into …

Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan

Faculty Publications

We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ/mm². Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 10⁴, which is limited by both solvent …

Development, Characterization, And Optimization Of Process For Minimal Functional Barrier And Channel Width In Nitrocellulose Paper Microfluidic Diagnostic Platforms, Ryan Daniel Silva

Biomedical Engineering

A central goal of diagnostic microfluidics is to reduce the cost of diagnostic medicine by reducing the equipment and reagents needed to perform diagnostic tests. The literature has demonstrated that a wax printer can be used to pattern nitrocellulose paper with hydrophobic barriers to direct a sample in a defined reaction path, eliminating the need for external pumps and controllers. However, manufacturing methods for minimizing sample volume (and thus reagent volume) in a paper-diagnostic chip have not been well defined. In this work, we experimentally determine manufacturing processes for creating functional features of minimal size—effectively reducing the sample size and …

The Fabrication & Characterization Of An Electrokinetic Microfluidic Pump From Su-8, A Negative Epoxy-Based Photoresist, Nash Anderson

Master's Theses

Microfluidics refers to manipulation, precise control, and behavior of fluids at the micro and nanoliter scales. It has entered the realm of science as a way to precisely measure or mix small amounts of fluid to perform highly controlled reactions. Glass and polydimethylsiloxane (PDMS) are common materials used to create microfluidic devices; however, glass is difficult to process and PDMS is relatively hydrophobic. In this study, SU-8, an epoxy based (negative) photoresist was used to create various electrokinetic microfluidic chips. SU-8 is commonly used in microelectromechanical design. Spin coating of various SU-8 formulations allows for 1 μm to 100 μm …