Materials Science and Engineering Commons^™

Buckling Analysis Of Auxetic Composite Laminates And Optimal Design Using Lamination Parameters And Machine Learning, Hans Bendon Maria Tamil Selvan

Mechanical and Aerospace Engineering Theses

Composite materials are widely used as structural panels in aerospace, automotive, and civil engineering applications, where buckling is often a critical failure mode. This thesis focuses on the analysis and design of composite laminates that maximize buckling performance under prescribed stiffness and thickness constraints.

The first part of the study investigates the buckling behavior of auxetic laminates, which exhibit a negative Poisson's ratio. While previous studies suggest that auxetic laminates can achieve higher critical buckling loads than non-auxetic laminates under simply supported boundary conditions with lateral restraint, the influence of other boundary conditions and plate aspect ratios has not been …

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 …

Synthesis And Application Of Cu-Based Ultrasmall Nanoparticles For Targeted Glioblastoma Treatment, Ryan T. Hart

Material Science and Engineering Dissertations - Archive

Glioblastoma (GBM) is a highly malignant form of brain cancer with a bleak prognosis. Current maximal treatment involves surgical resection followed by chemo-or radiotherapy. Two critical barriers make treating GBM a formidable challenge. First, the tumor's tendril-like proliferation throughout healthy brain tissue often makes complete surgical removal and conventional radiation insufficient. Second, the blood-brain barrier (BBB), which protects the brain, unfortunately also shields GBM from life-saving anti-cancer drugs. Here, we develop a radioactive nanoparticle-based therapy that directly confronts these limitations, offering a new strategy for GBM treatment.

Prostate-specific membrane antigen (PSMA) is a promising target for glioblastoma (GBM) treatment because …

Phase-Field Modeling Of A Protective Layer For The Suppression Of Dendrites In Metallic Anode-Based Rechargeable Batteries, Bharat R. Pant

Material Science and Engineering Dissertations - Archive

Metallic anodes, such as Lithium (Li) and Zinc (Zn), offer promise for the development of high-capacity rechargeable batteries. However, metallic anode-based batteries suffer from severe dendrite growth during the plating process, which poses safety hazards and accelerates capacity degradation. Experimental studies suggest that using a protective coating on the anode surface could potentially mitigate dendrite growth and prolong the battery’s life. However, there are limited theoretical studies on the inhibition effect of a protective layer on dendrite growth. Herein, we developed a phase-field model to simulate the impact of a protective layer on the plating and stripping cycle for Li …

Fabrication Of Microscale Oxide Architectures On Silicon Via A Cmos-Compatible, Deposition-Last Process, Jamal A. Brown

Material Science and Engineering Theses - Archive

This work explores the feasibility of integrating complex oxide devices on silicon using a CMOS-compatible, deposition-last approach. While previous demonstrations of this method have succeeded at larger scales, this study focuses on extending the process to microscale features, with lateral dimensions as small as two microns. The fabrication sequence begins with photolithographic patterning and reactive ion etching of the silicon substrate, followed by the deposition of a silicon nitride mask to delineate device regions. We then epitaxially grew SrTiO3 and La-doped SrTiO3 layers on top of the nitride mask via molecular beam epitaxy. Electrical transport measurements of the La:STO layer …

Engineered Biomimetic Muscle Graft For Skeletal Muscle Regeneration, Julia O. Aguirre

Bioengineering Theses - Archive

This study aims to develop a synthetic muscle graft that closely mimics the architecture, viscoelastic properties, and bio-signaling characteristics of natural skeletal muscle. By analyzing the native skeletal muscle microstructure, biochemical, and mechanical properties, we establish design parameters for a biomimetic scaffold. The engineered graft integrates tunable mechanical compliance, aligned microarchitecture, and signaling cues to promote cell recruitment, adhesion, proliferation, and maturation. To further enhance biofunctionality, an electrically conductive polymer was incorporated to improve the electrical conductivity, and the graft was loaded with the bioactive lipid signaling mediator “Prostaglandin E2” (PGE2) to support myogenesis during muscle regeneration. The grafts were …

Integrating Off-Spec Scms Into Plc Blends, George A. Qubty

Civil Engineering Theses - Archive

Off-spec supplementary cementitious materials (SCMs) remain underutilized due to variability in reactivity and non-conformance with existing standards. This study evaluates the hydration behavior and fresh-state and mechanical performance of these materials in Portland limestone cement (PLC) systems. One Class F fly ash (FA), one bottom ash (BA), and two calcined clays (HACC and LACC) were evaluated as 20 % replacements to PLC. Hydration behavior was characterized using isothermal calorimetry and thermogravimetric analysis (TGA), while fresh-state and mechanical performance were assessed through flow table, Vicat setting time, load–crack mouth opening displacement (CMOD) flexural testing, and compressive strength testing. HACC increased compressive …

Graphene-Polymer Nanocomposite For Electromagnetic Interference Shielding, Ravi Venkata Surya Sai Mogilisetti

Mechanical and Aerospace Engineering Theses - Archive

Polymers have widespread usage in most industries, such as aerospace, automotive, telecommunications, and medicine, mainly because they have a positive lightweight nature and excellent mechanical properties. One significant advantage of polymeric materials is their ability to combine nano-fillers, greatly enhancing their mechanical, electrical, and thermal properties. In the category of polymer matrices, polypropylene (PP) is notable for its low cost, ease of processing, and balanced mechanical properties. However, its relatively lower modulus and strength limit their applications in high-performance engineering. This research explores the addition of graphene into polypropylene to improve its mechanical properties and establish a conductive network for …

Amplification-Free Rapid Detection Of Specific Oligonucleotides Through Formation Of Core-Satellite Nanostructures On Solid Substrates, Vineet Kumar Jayakrishnan

Material Science and Engineering Theses - Archive

A rapid, portable, and highly sensitive method for detecting specific pathogens like Covid-19 would be invaluable for public health and emergency responses. The current standards like PCR and RT-PCR, are incredibly sensitive but also time-consuming, require skilled personnel, and demand substantial lab space. Here, we propose an alternative method capable of detecting specific oligonucleotide sequences within just 3 minutes, using a portable silicon or glass substrate (6 mm x 9 mm). We demonstrated this using 67-mer oligonucleotides with a Covid-19 sequence as a model system, achieving a detection sensitivity down to 1 nM. Our approach involves sandwiching target COVID-19 oligonucleotides …

Investigation Of Bone Structure And Composition Differences In Osteofibrous Dysplasia And Neurofibromatosis Type 1, Farzaneh Fereidouni

Material Science and Engineering Dissertations - Archive

Abstract

Investigation of Bone Structure and Composition Differences in Osteofibrous Dysplasia and Neurofibromatosis Type 1

Farzaneh Fereidouni, Ph.D.

The University of Texas at Arlington, 2024

Supervising Professor: Harry F. Tibbals

Bone genetic diseases such as Osteofibrous Dysplasia (OFD) and Neurofibromatosis type 1 (NF1) present significant challenges, particularly in children, due to their effects on skeletal homeostasis. This study aims to apply advanced material analysis to elucidate the biological disparities associated with OFD and NF1 bone dysplasia and contribute to developing diagnostic protocols and remediation approaches for these and similar bone disorders.

By employing various analytical methods, including analysis of mineral-to-matrix …

Sub-1k Cold Electron Transport At Room Temperature, Anthony Martinez

Material Science and Engineering Dissertations - Archive

Thermally excited electrons at the high-energy tail of the Fermi-Dirac distribution impose fundamental limitations on the performance of solid-state electronic and spintronic devices. For example, the thermally excited electrons obscure the Coulomb blockade essential for single-electron transport. The hot electrons can also overcome the energy barrier of Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs), causing unwanted leakage currents that lead to excessive power consumption in the integrated circuits. This study investigates an approach in which quantum states are used to manipulate electron tunneling, blocking the transport of thermally excited hot electrons, thereby enabling cold-electron transport at room temperature. Here two heterogeneous quantum wells …

Kissing Bond Assessment In Adhesive Bonded Carbon Fiber Reinforced Composites Using Dielectric Spectroscopy, Minhazur Rahman

Mechanical and Aerospace Engineering Dissertations - Archive

The widespread use of fiber-reinforced composites in industries such as space, aviation, automobiles, and construction necessitates the formation of robust composite joints between critical structural components. Although adhesive-bonded joints are superior with improved load distribution and reduced weight, they are often overlooked in favor of bolted joints and mechanical fasteners due to the lack of reliable Non-Destructive Evaluation (NDE) techniques for adhesive-bonded composites. The anisotropic nature of the substrate and the intricate interfacial interactions between the adherend and adhesive material present significant challenges for conventional NDE methods. Moreover, weak adhesive bonds can result from uncontrolled manufacturing parameters, such as accidental …

Experimental Investigations And Optimization Of 3d Printed Cellular Structures For Protection Against Traumatic Brain Injury, Aaron R. Jackson

Mechanical and Aerospace Engineering Dissertations - Archive

Traumatic Brain Injury (TBI) disrupts brain function due to head impacts, blast exposures, and ballistic penetrations. It is a significant cause of mental health issues and disability, particularly among military personnel. Historically, combat helmets were designed primarily to protect against fragments. However, recent data highlights the need for helmets that also protect against blast and blunt impacts. Effective TBI prevention requires helmets that address various energy threats while remaining lightweight. A critical metric in this effort is head acceleration, which is closely linked to injury across different scales of brain damage.

Four lattice structures were 3D printed using Digital ABS …

Synthesis Of Ni-Based Intermetallics By Electrolytic Plasma Processing Of Ti And Ti-Based Alloys, Chuzhong Zhang

Material Science and Engineering Dissertations - Archive

EPP is an innovative surface modification technique that enables the deposition of metal ions from the electrolyte and their integration with substrate atoms to form intermetallic compound surface layers. EPP offers advantages such as high deposition rates, environmental cleanliness, and operational simplicity. In this study, Ni-Ti intermetallic layers were successfully synthesized on a Ti-6Al-4V substrate using EPP. The properties of the resulting Ni-Ti intermetallic layers were characterized using SEM, EDS, XRD, TEM, nanoindentation, and tribology tests.

This work aims to understand the fabrication mechanism and investigate the effects of various processing parameters on the EPP process. Key factors such as …

Generalizable Fugitive Carrier Method For 3d Printing Of Hydrogels, Hakan Arslan

Mechanical and Aerospace Engineering Dissertations - Archive

Hydrogels, with physical characteristics resembling biological soft tissues, hold great potential for bioinspired and biomedical applications. However, using them in additive manufacturing systems has challenges because of their poor mechanical and rheological properties. In response to these challenges, we introduce a fugitive carrier method, a novel and generalizable approach for materials incompatible with pneumatic-based extrusion three-dimensional (3D) printers. Our developed fugitive carrier method allows the 3D printing of a broad spectrum of hydrogel precursors with low viscosity while retaining their inherent properties. This technique has been successfully demonstrated by creating biomimetic structures with anisotropic and programmable systems utilizing temperature-sensitive hydrogel …

Quantitative Modeling Of Micro Discharge And Oxide Growth In Plasma Electrolytic Oxidation Of Titanium, Kingsley I. Ochiabuto

Material Science and Engineering Dissertations - Archive

Plasma electrolytic oxidation (PEO) has been extensively applied in the past to improve the tribological properties of titanium and its alloys allowing their widespread use in industrial applications. However, the complete PEO mechanism of action remains unclear. While there are several mathematical models providing useful insights into the PEO process, they do not fully incorporate the effect of applied potential on the outcomes of PEO. In this work, we develop an experimentally informed computational model by expanding on the dielectric breakdown model. We incorporate experimental data to extract key parameters, exploring the iterative dependency of the oxide thickness and ionic …

Spray-On Sensor Formulations That Enable Detection Of Physical And Chemical Stimuli, Priyanka Shiveshwarkar

Bioengineering Dissertations - Archive

Polydiacetylene based materials have been used for a variety of liquid phase sensing applications. There remains a need for low cost, easy-to-read gas phase sensors for continuous monitoring of physiological parameters and environmental hazards at work or at home. Such sensors could have applications in everyday life, for example as point-of-care or at home testing devices to enable early detection of disease to reduce healthcare costs. Making accessible and non-invasive technologies for monitoring of health and health risks provides individuals with the ability to be proactive in regard to their health and safety. In other examples, environmental monitoring systems could …

Graphene Reinforced Polymer Composite For Small-Scale Vertical Axis Wind Turbine Rotors, Kunal A. Bachim

Mechanical and Aerospace Engineering Theses - Archive

Polymers have evolved as an indispensable asset in various sectors ranging from packaging and construction to energy and aerospace. However, the accumulation of polymer waste poses a necessity to shift toward sustainable waste management processes. Mechanical recycling is a primary method in establishing a circular economy approach for polymers. However, a fundamental challenge arises in this process: a decrease in the mechanical performance of the recycled product compared to that of its pristine counterpart.

This project addresses the challenge of enhancing the recyclability of polyethylene terephthalate (PET) from discarded polymer material by incorporating graphene nanoparticles into the polymer matrix during …

Enhancing Electromigration Reliability In Solder Interconnects Through Microstructure Control And Thermomechanical Failure Mechanisms In Thin Metal Lines Under Surge Current Conditions, Hariram Mohanram

Material Science and Engineering Dissertations - Archive

The relentless miniaturization of semiconductor devices has intensified reliability challenges in electronic packaging, particularly for solder interconnects and thin metal lines. This dissertation investigates two critical failure mechanisms—electromigration (EM) and thermomechanical fatigue (TMF)—and explores strategies to mitigate these effects. Electromigration, driven by high-density current-induced atomic migration, significantly impacts solder interconnects. This study examines the role of Under-Bump Metallization (UBM) and solder microstructure in improving EM reliability. Findings reveal that thicker UBMs delay void nucleation and enhance EM resistance, while the absence of UBM leads to failure through vertical void propagation. Additionally, grain orientation, particularly the c-axis alignment in Sn grains, …

Degree Of Dispersion/Exfoliation And Surface Functionalization Of 1d And 2d Carbon Nanostructured Materials: Interface Interactions And Effects On Mechanical Properties, Michail Margas

Material Science and Engineering Dissertations - Archive

The development of advanced cementitious nanocomposites relies heavily on understanding the interfacial interactions between carbon-based nanomaterials and the cement matrix, which significantly influence the material’s performance. The goal of this dissertation is to investigate the effect of dispersion/exfoliation and surface functionalization of 1D multiwall carbon nanotubes (MWCNTs), carbon nanofibers (CNFs), and 2D graphene nanoplatelets (GNPs) in aqueous suspensions on the interface interactions of nanoengineered cementitious composites. The first objective of this dissertation is to quantitatively evaluate the degree of nanomaterial dispersion for MWCNT and CNF suspensions, in a converging manner for cement-based materials applications using spectroscopic techniques, such as UV-vis …

Process-Driven Microstructure Tailoring During Additive Manufacturing Of Ti-6al-4v, Ahmet Alptug Tanrikulu

Material Science and Engineering Dissertations - Archive

In recent years, additive manufacturing (AM) has attracted the attention of many researchers due to the technology providing opportunities in terms of improved functionality, production repeatability, efficiency, and cost and time issues. While AM techniques made possible the realization of complex geometries, their use in critical applications have faced challenges due to the anisotropic characteristic of AM-built parts. More specifically, non-equilibrium AM processes involve steep temperature gradients and rapid solidification, yielding a unique microstructure, e.g., columnar-shaped grains with preferred texture, in final AM-built products and hence anisotropic mechanical properties. Despite significant studies on improving the microstructure of AM-built parts, it …

Spatially Resolved Elastic Modulus Of Magnesium Silicate Hydrate: A Cementitious Material, Arif Syed

Material Science and Engineering Theses - Archive

Magnesium-based cements such as magnesium silicate hydrate (MSH) have drawn interest as an environmentally friendly substitute for ordinary Portland cement because of their potential for reduced carbon footprint. The precise determination of these materials' elastic moduli is important to better assess their mechanical performance. Atomic force microscopy (AFM) is an effective tool for precise and spatially resolved quantification of nanomechanical characteristics of materials, including thin films. In this study, elastic modulus maps of MSH grown on single crystal mica surfaces were obtained using amplitude modulation-frequency modulation AFM. The effects of the Mg:Si ratio and morphology on the elastic modulus of …

Assessment Of Joule Heating Properties Of Various Solder Alloys In Bga Assembly, Jimmy-Bao D. Le

Material Science and Engineering Theses - Archive

The continuing demands for smaller, yet higher performance devices have resulted in many revolutionary changes in device packaging in recent years, including the change in package form factors, structure, and the type of solder alloys used for the assembly. Because solder joints are exposed to various electrical and thermo-mechanical stresses, not only at use condition but also during their process into the assembly, they are prone to failure. Especially concerned in this respect is the current density that the solder joint is subjected to as it determines the level of Joule Heating (JH), thus the solder temperature, significantly affecting the …

Study Of Alloy Effect On Electromigration In Sn Solder Alloys, Geng Ni

Material Science and Engineering Dissertations - Archive

This dissertation presents experimental results about the alloy effect on the Electromigration (EM) of Sn in Sn-based binary and ternary alloys. By using cross-stripe configuration, the alloy effect on EM of Sn can be characterized from marker polarity, and the migration of alloy element under EM can be measured from marker front motion. In the dissertation, the mechanism of alloy effect on EM of Sn, “Two-Phase equilibrium”, will be introduced. Electromigration is a phenomenon where metallic atoms are migrated at the direction of electron flow under high current density. In response to the demands for greater speed and smaller size, …

Dispersion Study Of Metal-Organic Frameworks And Synthesis Of Mof-High-Density Polyethylene Fibers, Sathvika Gondi

Material Science and Engineering Theses - Archive

Metal-Organic Frameworks (MOFs) are a highly versatile class of materials with a wide range of potential applications in gas storage, separation, catalysis, drug delivery, and sensing. The ability to tailor the properties and functionalities of MOFs by varying the organic linkers and inorganic nodes makes them highly attractive for a wide range of applications. The unique properties of MOFs also make them promising materials for fundamental studies in materials science and chemistry. The current investigation focuses on the dispersion study of MOFs and the synthesis of MOF-Polymer composites. The dispersions of MOFs in various organic solvents like ethanol, isopropanol, tetrahydrofuran, …

Carbon Fibers Recycling From Degraded Prepregs And Mechanical Properties Or Recycled Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

The size of the global composites market is anticipated to grow more than previously. Due to the rapidly rising volume of CFRP production, the waste from this material poses numerous problems and has significantly increased the socio-technological pressure to find sustainable composite recycling solutions. The problem is that recycling the composite part is challenging once its service life has expired. The same problem is true for the raw materials (prepregs) used in composite manufacturing. When the prepreg out-life/shelf-life is over, prepregs are abandoned, resulting in a loss of millions of dollars and an adverse environmental effect. In this study, the …

Artificial Intelligence Assisted Residual Strength And Life Prediction Of Fiber Reinforced Polymer Composites, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan

Institute of Predictive Performance Methodologies (IPPM-UTARI)-Archive

With the increased use of composite materials, researchers have developed many approaches for structural and prognostic health monitoring. Broadband Dielectric Spectroscopy (BbDS)/Impedance Spectroscopy (IS) is a state-of-the-art technology that can be used to identify and monitor the minute changes in damage initiation, accumulation, interactions, and the degree of damage in a composite under static and dynamic loading. This work presents a novel artificial neural network (ANN) framework for fiber-reinforced polymer (FRP) composites under fatigue loading, which incorporates dielectric state variables to predict the life (durability) and residual strength (damage tolerance) from real-time acquired dielectric permittivity of the material. The findings …

Physical Modeling Of Filament Growth And Resistive Switching In Metal Oxide-Based Rram, Kena Zhang

Material Science and Engineering Dissertations - Archive

Metal oxide-based resistive random-access memories (RRAM) exhibit several excellent performances, such as nanosecond switching speed, large write-erase endurance, and long retention time, and can potentially replace the traditional circuit elements for use as the fundamental units in next-generation hardware deep-learning or neuromorphic systems. The functionality of a metal oxide-based RRAM is attributed to an oxygen vacancy (V_O^(..))-rich conductive filament (CF), which initially forms, and later dissolves or regrows inside the oxide layer during the resistive switching process. However, the complicated interplays among the coexisting chemical, electrical, mechanical, and thermal effects during the formation, growth, and rupture of the CFs make …

Effects Of Graphene In High-Density Polyethylene Microfibers, Ashish Lal Sivadas Anilal

Material Science and Engineering Theses - Archive

High-Density Polyethylene uniquely can induce banded spherulites as it is crystallized from its melt. We studied the effects of graphene in the crystallography of banded HDPE by examining parameters such as the extent of twisting, spherulitic growth, and nucleation density. The application of graphene as a multifunctional filler in polymer matrices is a great topic of interest because graphene at low concentrations can bring many improvements in mechanical, electrical, and thermal properties. We synthesized graphene oxide by chemical oxidation of graphite and further studied its effects in the twisted crystallography of HDPE. Three batches of fibers were extruded: two batches …

Sub-10k Cold-Electron Injection To Silicon At Room Temperature, Ojas Tushar Bhayde

Material Science and Engineering Theses - Archive

The Fermi-Dirac thermal excitation of electrons results in unwanted off-state leakage currents in metal-oxide-semiconductor field-effect transistors (MOSFETs), leading to excessive power consumption in modern electronic devices. The electron thermal excitation results in a theoretical subthreshold slope limit of 60 mV/decade at room temperature, which forces the devices to use a high supply voltage leading to high power consumption. This study investigates a new architecture capable of suppressing electron thermal excitation by using a quantum well (QW) as an energy filter. The QW energy filter is composed of a tunneling barrier 1 (0.5 to 1 nm Al2O3 or 0.3-1 nm Si3N4 …