Engineering Commons^™

Development Of A 3d-Printed Microfluidic Droplet-On-Demand System For The Deterministic Encapsulation And Processing Of Biological Materials, Chandler A. Warr

Theses and Dissertations

The growing threat of antimicrobial resistance is among the largest concerns in the world today. One method under development to combat this issue is the encapsulation of microbes in microfluidic droplets for single-cell testing. This method may be able to circumvent the need for a traditional positive cell culture which consumes the majority of the testing time using current diagnostic methods. This dissertation presents a method by which to deterministically encapsulate microbes using an artificial intelligence object detection algorithm and a Droplet-On-Demand microfluidic device. To accomplish this, the Droplet-On-Demand microfluidic device was first developed using a unique 3D-printing manufacturing method. …

A Nanofiber-Embedded Microfluidic Platform For Studying Neurobiology, Donghee Lee, Navatha Shree Sharma, S. M. Shatil Shahriar, Kai Yang, Zheng Yan, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Due to their biomimetic properties, electrospun nanofibers have been widely used in neurobiology studies. However, mechanistic understanding of cell-nanofiber interactions is challenging based on the current in vitro culture systems due to the lack of control of spatiotemporal patterning of cells and difficulty in monitoring single cell behavior. To overcome these issues, we apply microfluidic technology in combination with electrospun nanofibers for in vitro studies of interactions between neurons and nanofiber materials. We demonstrate a unique nanofiber embedded microfluidic device which contains patterned aligned or random electrospun nanofibers as a new culture system. With this device, we test how different …

Developing Ultra-High Resolution 3d Printing For Microfluidics, Kent Richard Hooper

Theses and Dissertations

Building upon previous research on Digital Light Projection (DLP) 3D printing for microfluidics, in this thesis I performed the detailed design and fabrication of a novel DLP 3D printer to increase resolution and device footprint flexibility. This new printer has a pixel resolution twice that of our group’s previous printers (3.8 μm vs 7.6 μm). I demonstrated a new state of the art for minimum channel width, reducing the minimum width to 15 μm wide (and 30 μm tall). This is an improvement over the previous smallest width of 20 μm. This printer also has the capacity to perform multiple …

A Rapid And Ultra-Sensitive Biosensing Platform Based On Tunable Dielectrophoresis For Robust Poc Applications, Yu Jiang

Doctoral Dissertations

With the ongoing pandemic, there have been increasing concerns recently regarding major public health issues such as abuse of organophosphorus compounds, pathogenic bacterial infections, and biosecurity in agricultural production. Biosensors have long been considered a kernel technology for next-generation diagnostic solutions to improve food safety and public health. Significant amounts of effort have been devoted to inventing novel sensing mechanisms, modifying their designs, improving their performance, and extending their application scopes. However, the reliability and selectivity of most biosensors still have much to be desired, which holds back the development and commercialization of biosensors, especially for on-site and point-of-care (POC) …

Optofluidic Manipulation With Nanomembrane Platforms Used For Solid-State Nanopore Integration, Zachary J. Walker

Theses and Dissertations

Nanopore technology has introduced new techniques for single particle detection and analysis. A nanopore consists of a small opening in a membrane on the nanometer scale. Nanopores are found in nature and are utilized for transporting molecules through biological membranes. Researchers have been able to mimic naturally forming biological nanopores and utilize them for a variety of sensing applications. Nanopores, fabricated either organically or inorganically, can be used for detecting biomarkers such as proteins, nucleic acids, and metabolites that translocate the membrane by way of the nanopore. Constant ionic current flow is measured through the nanopore by way of a …

Designing A Self-Regulating And Portable Heating Device For A Microfluidic Based Biosensor, Riya Mahajan

Discovery Undergraduate Interdisciplinary Research Internship

Paper-based biosensors are powerful microfluidic analytical devices that are potentially useful for a wide range of applications, ranging from medical diagnostics to agricultural and environmental monitoring. Molecular diagnostics have limitations because they need to send samples back to a centralized laboratory, which increases the cost and turnaround time of the test. This project aims to create a simple-to-use, low-cost, and portable heating system that would facilitate the creation of a field-deployable paper-based analytical device that can incubate the sample at elevated temperatures for conducting isothermal molecular assays. Our design aims to miniaturize a commercial water bath and will be fabricated …

Microfluidic Flow Focusing Platforms For Optofluidic Droplet Laser Development, Chen Zhang

Electrical Engineering Dissertations

ABSTRACT: Optofluidic droplet lasers have been developed for different applications in biomedical sciences, such as biosensing, cell tracking, tissue imaging, on-chip spectroscopy, and flow cytometry. Utilizing different generation methods, droplet lasers can be categorized as either static droplet lasers or droplet lasers on the flow. Static droplet lasers, which are supported by a surface or levitated by an external force, can be optically probed for an extended period of time, and thus enabling continuous monitoring of the lasing emission. However, static droplet lasers suffer from low-throughput generation, large size distribution, and poor reproducibility. In contrast, droplet lasers on the flow …

A New Approach For 3d Printed Microfluidic Device Design Based On Pre-Defined Components, Cassandra Ester Slaugh

Theses and Dissertations

3D printing for microfluidic device fabrication has received considerable interest in recent years, in part driven by the potential to dramatically speed up device development by reducing device fabrication time to the minutes timescale. Moreover, in contrast to traditional cleanroom-based fabrication processes that require manual production and stacking of a limited number of layers, 3D printing allows full use of the 3D fabrication volume to lay out microfluidic elements with complex yet compact 3D geometries. The Nordin group has successfully developed multiple generations of high resolution printers and materials for microfluidic devices that achieve this vision. However, because of the …

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 …

Verification Of A Digital Microfluidics Platform, Karanpartap Singh

Electrical Engineering

The electrowetting effect describes the change in contact angle between a solid surface and electrolyte in response to an applied electric potential difference. Given a planar array of individually-actuated electrodes, electrowetting can be used to transport, mix, and separate picoliter to microliter-sized droplets of liquid on a dielectric layer. Applications of this phenomenon range from lab-on-a-chip and other microfluidic devices to liquid lenses capable of altering their topology and focus within milliseconds.

This project extends prior work simulating the dependence of droplet velocity on actuation voltage and demonstrates observed physics on a physical platform. The simulation portion of this project …

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 …

Editorial For The Special Issue On Micromachines For Non-Newtonian Microfluidics, Lanju Mei, Shizhi Qian

Mechanical & Aerospace Engineering Faculty Publications

In lieu of an abstract, this is an excerpt from the first page.

Microfluidics has seen a remarkable growth over the past few decades, with its extensive applications in engineering, medicine, biology, chemistry, etc [...]

Green-Route Synthesis Of Halide Perovskite Materials And Their Optoelectronic Properties, Xiaobing Tang

Theses and Dissertations--Chemical and Materials Engineering

Colloidal semiconductor quantum dots (QDs), also called as nanocrystals (NCs), are a class of functional materials with extraordinary properties, which are different from their bulk counterparts and benefit from their exclusive quantum confinement (size) effect. Semiconductor exhibits the quantum confinement effect when the characteristic size of the semiconductor is comparable to or smaller than the de Broglie wavelength of the electron wave function and/or the exciton Bohr diameter of the bulk semiconductor. In recent years, metal halide perovskite NCs, as next-generation semiconductor materials for lighting and display, have aroused a wide attention due to their excellent optoelectronic properties. However, traditional …

The Study Of 3d Micro-Fluid Printing In Aqueous Two-Phase System, Mian Huang

Dissertations and Theses

Aqueous two-phase system (ATPS) is a technology that allows phase separation in an aqueous environment. This technology can be used for the separation, extraction and purification of a variety of biomolecules and thus gained great attention in industry and academia. This thesis is a combination of ATPS, 3D printing, and microfluidics technologies and realizes the printing of biocompatible aqueous structures in another aqueous matrix. The objectives of this thesis include 1) customizing a regular thermal extrusion 3D printer for printing 3D aqueous structures, 2) printing 3D aqueous structure in an aqueous matrix, and 3) studying the stability of the printed …