Materials Science and Engineering Commons^™

Strain-Induced Nonvolatile Domain Switching And Tunable Elastic Modulus In Ba1-Xsrxtio3 Membrane By Phase-Field Simulation., Laveeza Ahmad

Material Science and Engineering Dissertations

Ferroelectrics underpin a broad spectrum of technological applications due to its switchable ferroelectric polarization and the associated electro-mechanical responses under electrical, optical, thermal, and mechanical stimuli. Recent advancement in membrane technology offers new opportunities to tune ferroelectric polarizations via mechanical strains at relatively large magnitude and scale. However, its influence on the tunability of mechanical responses of the membrane remains underexplored. Herein, we developed a phase-field model for free-standing Ba_1-xSr_xTiO₃ ferroelectric membranes with stress-free boundary conditions on top/bottom surfaces and achieved strain-induced nonvolatile ferroelectric domain switching in the membrane. It is discovered that a …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …

Development Of Alternative Plasma Etching Techniques For The Selective Removal Of Tan With Respect To Sioch Dielectric Materials To Enable Future Back-End-Of-The-Line Scaling, Ivo Otto Iv

Electronic Theses & Dissertations (2024 - present)

Transistor scaling has continued according to Moore’s Law for over fifty years. As transistor size decreases, adequate power delivery is required to enable transistor scaling without performance loss. Power delivery is provided by a metal interconnect network with insulating dielectric that connects the transistor level to the power source, the signal speed within this metal line network limiting transistor level switching speeds. Reduction of signal delay has moved from primarily dimension-based improvement towards adoption of conductor and dielectric materials with lower resistivity and a reduced dielectric constant value, respectively: transitioning from Al/SiO₂ to Cu/low-κ SiOCH. With this transition comes …

Next-Generation Computing Hardware: Advancements In Tantalum Oxide Reram For Ai And Neuromorphic Applications, Rajas Ravindra Mathkari

Electronic Theses & Dissertations (2024 - present)

The rapid development of artificial intelligence, machine learning, and data-intensive computing has exposed the fundamental limitations of conventional von Neumann architectures, in which energy and time are continuously lost transferring data between physically separate memory and processing units. In contrast, the human brain performs complex computations directly at the point of memory storage through billions of parallel synaptic connections, a paradigm known as in-memory computing. Realizing this in hardware requires memory devices that are fast, energy-efficient, non-volatile, and capable of storing multiple resistance levels in an analog manner. Resistive Random Access Memory (ReRAM) based on tantalum oxide (TaOx) is one …

Modulation Of Prussian Blue Redox Signaling By Molecular Imprinting For Reagent-Free Electrochemical Detection Of Emtricitabine, Abdellatif Ait Lahcen, Gymama Slaughter

Center for Bioelectronics Publications

Reagent-free electrochemical sensors offer significant benefits for rapid, affordable point-of-care drug testing. In this study, we introduce a novel, reagent-free electrochemical sensor based on a molecularly imprinted polymer (MIP) specifically designed for the selective detection of Emtricitabine (FTC), a common antiretroviral used in HIV therapy. The sensor uses laser-induced graphene (LIG) electrodes, renowned for their high conductivity and porosity, ideal for electrochemical sensing. To enable reagent-free operation, the LIG surface was electrochemically coated with Prussian Blue, serving as a redox-active layer. Next, an MIP-PPy film was electropolymerized onto the Prussian Blue surface in the presence of FTC as a template, …

Ion-Imprinted Polymer-Based Sensors For Toxic Metal-Ion Detection In Water: Coordination Chemistry, Transduction Strategies, And Environmental Applications, Ghita Yammouri, Gymama Slaughter

Center for Bioelectronics Publications

Toxic metal contamination in aquatic environments remains a persistent threat to human health and ecosystems. Yet, the high cost, infrastructure demands, and centralized nature of conventional analytical methods constrain routine monitoring. Ion-imprinted polymers (IIPs), a subclass of molecularly imprinted polymers, have emerged as promising synthetic recognition materials for metal-ion sensing because they generate coordination-defined binding sites with high selectivity, chemical stability, low cost, and reusability. This review summarizes recent advances in Ion-imprinted polymer (IIP)-based sensing technologies for toxic metal-ion detection in water from 2016 to 2026. It examines the fundamental recognition chemistry of IIPs, major synthesis strategies used to generate …

Stiffening Of Soft Silicone Upon Deep Uv Treatment As Characterized Using Nanoindentation, Amanda Wilder, Zaria Booth, Caden Obermeyer, Saika Sharmin, Venkat Maruthamuthu

Mechanical & Aerospace Engineering Faculty Publications

Silicones are elastomers that have a wide variety of uses, including biomedical applications such as the coating of biomedical devices and as implants. Soft silicones with mechanical properties similar to those of biological tissues have particularly gained use as substrates for cell culture in mechanobiology studies. In this context, it would be desirable to be able to alter their surface mechanical properties with a relatively simple physical treatment. While deep ultraviolet (deep UV) or ultraviolet C (UV-C) treatment has been previously used as a surface treatment method for stiffer silicones formulations, the effect of this treatment on soft silicones relevant …

A Study In The Advanced Manufacturing Of Full Solids Oxide Fuel Cells (Sofcs) Via Aerosol Deposition (Ad) Methods With Macro- And Microstructural Defect Characterization, Davis A. Warmuth

Graduate Theses, Dissertations, and Problem Reports (ETD)

The goal of this work is to 3D print a full SOFC layer-by-layer using aerosol deposition (AD) at a resolution of 5 μm. To achieve this goal, several studies were undertaken to develop and optimize an AD system to use ceramic inks. A 130 kHz AD system was developed with 4 material pumps to allow for depositions of individual compositions of the in-situ mixture of multiple solutions to allow for the fabrication of functional gradients in three dimensions. This system was then programmed to deposit air electrode layers containing different material ratios and porous microstructures, comparing their electrochemical performance to …

Development And Additive Manufacturing Of Uv And Dual-Curable Elastomers For Soft Robotic Actuators And Embedded Sensors Via Direct Ink Writing, Emrah Demirkal

Graduate Theses, Dissertations, and Problem Reports (ETD)

The advancement of soft robotics requires materials and manufacturing methods that combine large deformation, structural stability, and integrated sensing within a single soft system. Conventional fabrication techniques often limit design flexibility and the incorporation of functional materials into soft structures. This dissertation addresses these challenges through the development of UV-curable and dual-curable silicone elastomers for the direct ink writing (DIW) of soft robotic actuators and embedded sensors.

UV-curable elastomers were first synthesized through thiol-ene click chemistry using poly(mercaptopropylmethylsiloxane) (MMPS) and vinyl-terminated polysiloxane (VPS). Their curing behavior, rheological response, printability, and mechanical properties were evaluated for DIW. These materials enabled rapid …

Eco-Friendly Solvent-Based Fabrication Of Single-Layer And Polydopamine-Modified Bilayer Pvdf-Hfp Membranes, Eesh M. Kulshrestha

Theses and Dissertations--Chemical and Materials Engineering

The growing global demand for clean drinking water has intensified the need for advanced water treatment technologies capable of efficiently removing contaminants while maintaining environmental sustainability. Polymeric membrane systems have emerged as an effective approach for water separations due to their high separation efficiency, simplicity, and adaptability to a wide range of water treatment applications. However, traditional membrane fabrication processes often rely on toxic organic solvents, such as N-methyl-2-pyrrolidone (NMP) and diemethylacetamide (DMAc), which pose environmental and health risks. These concerns have led to an increase in regulatory restrictions, primarily through the Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) …

Aqueous Synthesis Of Luminescent Semiconductors For Opto-Electronic Applications, Saurabh Singh

Theses and Dissertations--Chemical and Materials Engineering

The advancement of opto-electronic and scintillation technologies relies heavily on developing low-temperature, eco-friendly, and scalable synthesis routes for high performance luminescent halide-based semiconductor materials. However, traditional synthesis methods for halide-based semiconductors, including hot-injection, solvothermal, solid-state reactions, Ligand-Assisted Reprecipitation (LARP), microwave-assisted synthesis, and thin film deposition techniques (spin coating, physical vapor deposition (PVD), chemical vapor deposition (CVD), etc.), often demand toxic organic/inorganic solvents, elevated processing temperatures, and high vacuum/inert environments. Such constraints limit their scalability, raise environmental concerns, and impede their commercial-level device integration. This research overcomes these long-standing challenges by employing water as a powerful crystallization-directing, and environmentally benign medium …

Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Turab S. Rizvi

Undergraduate Research Posters

Developing sustainable, high-efficiency cooling technologies is vital to addressing 21st century energy challenges. This research focuses on magnetic refrigeration, an environmentally friendly cooling method utilizing the magnetocaloric effect to regulate temperature using magnetic fields. This approach offers greater energy efficiency than conventional vapor-compression systems by eliminating harmful refrigerants. The critical component is the regenerator, made of magnetocaloric material and transfers heat between the magnetic material and a fluid through parallel channels. Traditional designs such as packed beds of particles are prone to particle segregation, creating an undesirable pressure drop. The main goal of our research was to fix those flaws …

Aqueous Iron Electrowinning: From Electrolyte Engineering To The Unexplored Potential Of Acetate Systems, Chodwell N. Verenga

Dissertations, Master's Theses and Master's Reports

Iron electrowinning and electrodeposition sit at the intersection of classical metallurgy and developing sustainable manufacturing. With the iron and steel industry responsible for 7 - 9% of global CO₂ emissions, low-temperature electrochemical pathways for iron production have garnered significant research interest. This review examines the fundamental electrochemical principles governing iron deposition, the thermodynamic constraints imposed by the iron-water system, and the kinetic challenges posed by the parasitic hydrogen evolution reaction (HER). The three key electrolyte systems are objectively evaluated: acidic sulfate and chloride electrolytes, alkaline suspension electrolytes and water-in-salt electrolytes. Their operating parameters, faradaic efficiencies, energy consumption and deposit characteristics …

Investigation Of Fine-Grain Cu And Cu Alloys For Low-Temperature Hybrid Bonding Applications, Sarabjot Singh

Electronic Theses & Dissertations (2024 - present)

Hybrid bonding has emerged as a key enabler for next-generation three-dimensional (3D) integration, offering fine-pitch interconnects and improved electrical performance. However, conventional Cu–Cu hybrid bonding typically requires elevated temperatures to achieve sufficient diffusion and interface quality, posing challenges for temperature-sensitive device integration and process compatibility. This work investigates materials engineering approaches to enable low-temperature Cu–Cu bonding through both microstructure design and alloying strategies.

This work begins by examining grain refinement in Cu as a pathway to enhance diffusion through increased grain boundary density, providing efficient atomic transport without introducing additional elements. Three Cu-based systems Cu–Co, Cu–Ag, and Cu–Al were systematically …

High-Tcr Multivalence Vanadium Oxide Thin-Films From Deposition Parameter Control To Microbolometer Applications, Latika Susheel M. Chaudhary

Electronic Theses & Dissertations (2024 - present)

This thesis details the development of multivalence-nanostructured vanadium oxide (VOₓ) thin films for uncooled microbolometer applications, with a systematic optimization of magnetron-sputtering parameters. The temperature coefficient of resistance (TCR), resistivity, and optical response of VOₓ thin-film sensing layers are controlled by valence composition, grain growth, and surface morphology. The primary goal was to achieve a high TCR with low resistivity to improve thermal detector performance.

Multivalent VOₓ thin films were deposited on silicon, SiO₂, and glass substrates using DC magnetron sputtering. Three key parameters were systematically varied: Ar:O₂ ratio (18:2 to 15:5), deposition time (60–120 minutes), and DC power (300W …

Utilizing Coal For Mesophase Pitch-Based Carbon Fiber Production: Precursors, Processes, And Progress, Christina M. Thompson

Theses and Dissertations--Chemistry

Graphitic materials possess unique properties due to the unique combination of layered crystalline structure and carbon’s low atomic weight. High performance carbon fiber is one such example, displaying exceptional strength-to-weight ratios, stiffness, and thermal and chemical resistance. These properties render high performance carbon fiber a critical structural reinforcement material in the manufacture of composites across various industries, such as for automotive and aerospace applications. However, balancing fiber performance with precursor and processing costs remains a challenge. As alternative carbonaceous feedstocks are explored, coal has gained interest for utilization in graphitic products as a relatively abundant and low-cost source of aromatic …

Development And Characterization Of Flat And Flexible Rebco Cables For High-Field Accelerator Magnets, Emily Romancew

Graduate Research Theses & Dissertations

High-Temperature Superconducting (HTS) materials are at the forefront of innovation for fundamental particle physics. The next generation of particle accelerators aims to explore higher mass particles and is dependent on the ability to achieve higher fields in the 20–30 T range to keep machine size within a practical footprint. Current magnet technology relies on low-temperature superconductors (LTS) such as NbTi and Nb₃Sn, which are limited to fields of approximately 8–16 T, while high-temperature superconductors (HTS), particularly Rare-Earth Barium Copper Oxide (REBCO), offer a promising pathway toward higher-field magnets due to their ability to carry large currents at elevated magnetic fields. …

Molecular Diffusion In Chemically Amplified Resists For Euv Lithography, Eshan Dilina Thilakarathna

Electronic Theses & Dissertations (2024 - present)

Photolithography is a critical manufacturing step in high-volume manufacturing (HVM) of semiconductor devices, where a photoresist layer is used to transfer nanoscale patterns onto the underlying stack materials. As the microelectronics industry continues to move toward smaller node sizes, driven by Moore's Law. As a result, the tolerances for photoresist performance have become increasingly demanding, which necessitates simultaneous improvements in resolution, defectivity, and roughness. At advanced nodes, these performance limitations are governed by the fundamental stochastic nature of the photochemical processes occurring within the resist film itself, rather than the optical or tool-level constraints. Photon shot noise, the statistical distribution …

Regulation And Localization Of Urease In Sporosarcina Pasteurii: Implications For Coastal Protection, Amar Kosovac

UNF Graduate Theses and Dissertations

Coastal erosion is a persistent problem exacerbated by global warming. As the climate changes, the southeastern coast is likely to experience an increased frequency and intensity of storms, which can significantly damage the coastline. The coast is crucial as it serves as a habitat for numerous animals, supports tourism, and underpins infrastructure. Microbially induced calcite precipitation (MICP) is a novel method to enhance erosion resistance in sandy soils using the non-pathogenic bacterium Sporosarcina pasteurii. S. pasteurii produces urease to catalyze urea into bicarbonate, which drives the precipitation of calcium carbonate. Maximal expression of urease is a limiting factor for …

Mechanical Behavior Of Additively Manufactured Ti-6al-4v Eli Parts: Effects Of Laser Parameter Selection, Samuel Lopez

UNF Graduate Theses and Dissertations

Additive manufacturing (AM) of TI-6AL‑4V Extra‑Low Interstitial (ELI) enables complex geometries for fatigue‑critical medical device applications, yet fatigue performance remains sensitive to process‑induced defects. This work investigates the effect of laser process parameter selection on the microstructure, mechanical properties, and fatigue behavior of TI- 6AL‑4V ELI fabricated via laser powder bed fusion (L‑PBF) using a Renishaw RenAM system. The influence of laser parameters was isolated by holding powder chemistry, build orientation, scan strategy, sub‑transus annealing, and post‑processing constant between a non‑optimized baseline and an optimized parameter set selected based on tensile performance.

Optical microscopy showed the optimized condition exhibited improved …