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Enhanced Fabrication Of Microdroplet Generator Nozzle Arrays: Optimizing Koh Etching For Microfluidic Applications, Hongyu Bai
McKelvey School of Engineering Theses & Dissertations
Ultrasonic microdroplet generators are useful devices with broad applications ranging from aerosolized drug delivery to three-dimensional (3D) printing-based additive manufacturing. One such technology comprises a microfabricated array of nozzles with droplet production driven by a piezoelectric transducer. The present study focuses on refining a critical fabrication step, anisotropic wet etching of pyramidal nozzles using a basic potassium hydroxide (KOH) solution. Given the integral role of nozzle geometry in device operation, high-precision techniques including Reactive Ion Etching (RIE), Deep Reactive Ion Etching (DRIE), and KOH wet etching were employed. A tapering geometry is preferred for acoustic wave focusing and efficient droplet …
Novel Microfluidic Devices To Model The Interactions Between Lymphatics And Breast Cancer, Jade Weber
Novel Microfluidic Devices To Model The Interactions Between Lymphatics And Breast Cancer, Jade Weber
McKelvey School of Engineering 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 …
Quantifying Components Of Protein Translation And Metabolite Heterogeneity In Isogenic Microbial Populations, Alexander Schmitz
Quantifying Components Of Protein Translation And Metabolite Heterogeneity In Isogenic Microbial Populations, Alexander Schmitz
McKelvey School of Engineering Theses & Dissertations
Cell-to-cell variation in gene expression and metabolite levels have a significant impact on ensemble productivity of microbial bioproduction. New metabolic engineering tools and approaches are needed that consider cell cultures as an amalgam of uniquely behaving individuals to improve the slow commercialization of metabolically engineered systems. Stochastic cellular process including gene expression, metabolism, and growth lead to phenotypic variation between genetically identical cells. Understanding and the ability to control microbial phenotypic variation is key to improving microbial bioproduction metrics. During protein translation, codon usage strongly influences ensemble gene expression but the effect on the variation of gene expression was not …
Understanding The Interactions Between Acoustic Fields And Motile Microorganisms In Microfluidic Systems, Minji Kim
McKelvey School of Engineering Theses & Dissertations
Acoustofluidics utilizes ultrasonic standing waves in microscale fluidic channels to manipulate cells, microorganisms, and other objects sized from tens of nanometers to tens of microns. When exposed to an ultrasonic standing wave field, particles suspended in a fluid become confined to potential minima (nodes) of the acoustic field. I will present a number of related studies that involve the interactions between acoustic fields and motile microorganisms. First, I will show how an acoustic trap-and-release method enables rapid quantification of cell motility. As a demonstration, the newly developed motility assay is applied to discriminate swimming of wild-type and mutant Chlamydomonas reinhardtii …
Longitudinal Acoustic Traps: Design, Fabrication, And Evaluation For Biological Applications, Michael Moore Binkley
Longitudinal Acoustic Traps: Design, Fabrication, And Evaluation For Biological Applications, Michael Moore Binkley
McKelvey School of Engineering Theses & Dissertations
Acoustofluidics combine ultrasonic actuation with small-volume microfluidic channels to enable precise, contactless object manipulation for a range of applications from serial chemical processing to blood component separation and single-cell analysis. Micron- to millimeter-scale vibrational waves generate reproducible pressure fields within the microfluidic channels and chambers. By exploiting the material property mismatch between a particle (polymeric and silica beads, cells, etc.) and a suspending fluid, the acoustic radiation force is used to move particles toward regions of low (nodes) or high pressure (antinodes). An understanding of these field-particle interactions is applied to design and implement complicated channel architectures for preferential segregation …
On The Fabrication And Development Of Tissue On A Chip Devices With Included Perfused Vasculatures, Usama Ismail
On The Fabrication And Development Of Tissue On A Chip Devices With Included Perfused Vasculatures, Usama Ismail
McKelvey School of Engineering Theses & Dissertations
The advent of Tissue-on-a-Chip (TiOC) devices has provided a novel way for researchers to approach biological study and drug development. As a platform that enables human in vivo conditions to be accurately replicated ex vivo, TiOC can accelerate both fundamental biological research to answer basic questions regarding tissue behavior and function (e.g., cell-cell interactions in the tumor microenvironment (TME)) and translational research that includes testing of standard and novel therapeutics. The reported work focuses on development of processes and technologies common to two classes of TiOC. The first device is a single-layer, multi-compartment microfluidic device for investigation of pancreatic …
Microfluidic Assessment Of Stem Cell-Derived Pancreatic Beta Cells, Arvind Rajamani Srivatsava
Microfluidic Assessment Of Stem Cell-Derived Pancreatic Beta Cells, Arvind Rajamani Srivatsava
McKelvey School of Engineering Theses & Dissertations
Contemporary and traditional methods of perifusional analysis of cells, pancreatic β cells in particular, involve the utilization of costly equipment exhibiting difficulties in setup and inflexibilities in operation and application. Microfluidic devices in general are inexpensive, easy to fabricate and are capable of screening multiple microenvironmental conditions, with the potential to generate concentration gradients for the study of biological phenomena such as cell migration. Utilization of these devices for cellular fluorescence imaging is also possible, paving the way for more sophisticated methods of dynamic assessment. Herein, we fabricated a pre-designed microfluidic device from photolithography, containing microwells capable of immobilizing human …
Exploiting Click-Chemistry And Microfluidics To Map The Neuronal Itinerary Of App Processing And Amyloid-Beta Generation, Namratha Srinivas
Exploiting Click-Chemistry And Microfluidics To Map The Neuronal Itinerary Of App Processing And Amyloid-Beta Generation, Namratha Srinivas
McKelvey School of Engineering Theses & Dissertations
Alzheimer’s disease (AD) is a chronic neurodegenerative disease and is the sixth leading cause of death in the United States with approximately 5.5 million Americans diagnosed with it. The neuropathological hallmark includes extracellular senile plaques and intraneuronal neurofibrillary tangles. Recent GWAS studies have identified genes associated with AD, and have revealed several classes of genes implicated in disease pathogenesis. In particular, three general pathways associated with an increased risk of AD included: 1) cholesterol metabolism, innate immune system, and the membrane trafficking. Our lab has focused on intracellular trafficking as it relates to the processing of amyloid precursor protein (APP), …
Assessing Dprestin & Nadc1 (Indy) Interaction On Calcium Oxalate Crystal Formation In A Drosophila Model Of Kidney Stones, Jessica Lin
Undergraduate Research Symposium Posters
Calcium oxalate (CaOx) accounts for >70%of kidney stones, yet why CaOx stones form is poorly understood. While several factors contribute to the stone aggregation and growth, elucidating the roles of oxalate transporters can help demystify this phenomenon. Using a Drosophila model to study the formation and inhibition of CaOx crystals in the fly Malpighian tubule (MT), oxalate transport via dPrestin—the fly Slc26a6 Cl-/Ox2- exchanger was studied using both electrophysiology and MT dissection with CaOx birefringence assays. Here, the fly model suffices as it recapitulates renal oxalate excretion. Additionally, the mammalian dicarboxylate transporter NaDC1 (Indy in Drosophila) …
Design And Implementation Of Position-Encoded Microfluidic Microsphere-Trap Arrays, Xiaoxiao Xu
Design And Implementation Of Position-Encoded Microfluidic Microsphere-Trap Arrays, Xiaoxiao Xu
All Theses and Dissertations (ETDs)
Microarray devices are useful for detecting and analyzing biological targets, such as DNAs, mRNAs, proteins, etc. Applications of microarrays range from fundamental research to clinical diagnostics and drug discovery. In this dissertation, we consider a microsphere array device with predetermined positions of the microspheres. The microspheres are conjugate on their surfaces with molecular probes to capture the targets, and the targets are identified by the microspheres' positions. We implement the microsphere arrays by employing microfluidic technology and a hydrodynamic trapping mechanism. We call our device microfluidic microsphere-trap arrays. To fully realize the potential of the device in biomedical applications, we …