Mechanical Engineering Commons^™

Coupled Effects Of Sub-Atmospheric Pressure And Surface Structures On Pool Boiling Performance And Hysteresis Pathways, Mohammad Ishraq Hossain

Graduate Theses and Dissertations

The increasing power density of microelectronics has created a need for cooling technologies capable of maintaining low operating temperatures. Sub-atmospheric pool boiling of water is promising because reducing saturation pressure lowers the boiling temperature, enabling two phase cooling within electronics-relevant temperature limits. However, reduced pressure also affects CHF, HTC, and post-CHF recovery. In this work, pool boiling experiments were conducted on flat copper, microchannel copper, and micro-pin-fin copper surfaces over 10–100 kPa to examine the coupled effects of pressure and surface structure. CHF and HTC increased with pressure, while structured surfaces enhanced both relative to flat copper. Surface structure dominated …

Design, Fabrication, And Testing Of A Pdms-Based Nanochannel Using Nano Embossing, Cooper James Haskamp

Graduate Theses and Dissertations

DNA sequencing has become increasingly important in the field of biomedical research and clinical applications. Currently, the most well-established sequencing technique is ‘Sequencing by Synthesis’ with accuracy in the range of 99.2% to 99.74% and sequencing lengths of only 300 base pairs. Sequencing by Synthesis is a lab-based method that requires expensive equipment and fast parallel computing. It is not suitable for portable, on-site applications. A new technique known as ‘nanopore’ was developed to meet these requirements. Nanopore is an electrical sequencing method that relies on the translocation of a DNA molecule through a nanoscale pore, where the blockage current …

Tribological Evaluation Of A Graphite Coating Using A Custom Miniature Conveyor, Shae Threlfall

Mechanical Engineering Undergraduate Honors Theses

Reducing friction in conveyor systems has significant economic and environmental implications, as a substantial portion of energy losses originates at the belt-bed interface. This thesis outlines the design, construction, and validation of a miniature conveyor tribological test system. Unlike conventional tribometers, which impose concentrated point contacts, the miniature conveyor replicates the distributed load consistent with industrial conveyor systems. It can measure real-time mechanical responses of steel samples coated in a low friction coating.

The mini conveyor was validated by evaluating three materials: uncoated mild steel, PDA/graphite coated steel, and Polytetrafluoroethylene (PTFE). Electrical power, temperature, sound, and acceleration were recorded. Electrical …

The Expectation Of Pain: Effects On Threshold, Tolerance, And Perception, Emma Paulus

Mechanical Engineering Undergraduate Honors Theses

Brain activity in pain-related regions of the cortex is thought to be influenced by interactions between expectations and incoming sensory information. However, the subjective experience of pain based on expectation has not been thoroughly explored. By changing visual and auditory cues to set expectation levels, a relationship between unconscious expectation of pain and actual sensory pain experienced was characterized. With IRB approval, volunteers were randomly and blindly grouped into low and high pain expectancy groups. Each group completed a survey about initial pain expectations before the muscle stimulation tolerance test, followed by a survey about actual pain perception after the …

Harness: Hybrid Architecture For Resilience In Networked Engineering System Simulations, Daniel Scott

Graduate Theses and Dissertations

This dissertation presents the development of HARNESS, a unified, domain-agnostic framework for the modeling, optimization, and evaluation of complex systems under conditions of degradation and uncertainty. The research addresses a persistent challenge in systems engineering: the lack of a generalizable, behaviorally grounded approach for quantifying resilience and robustness across diverse domains. HARNESS integrates graph-theoretic dependency modeling, GPU-accelerated evolutionary optimization, and agent-based simulation into a modular architecture that enables both system design and diagnostic analysis. The framework models system interdependencies through user-defined components, parameters, and constraints, allowing architectures to evolve dynamically while maintaining structural validity. A mutation-only genetic algorithm with a …

Stakeholder Perspective-Taking In Engineering Design: A Neurocognitive Approach, Megan C. Taylor

Mechanical Engineering Undergraduate Honors Theses

Stakeholder engagement is a critically important yet overlooked phase of engineering design. While addressing stakeholders is known to lead to more thoughtful design outcomes, little work has been done regarding how stakeholder personas influence brain activity while designing. This study asks if the introduction of stakeholder personas- short overviews of people affected by a design problem- affects brain activation in undergraduate students during three design tasks: stakeholder identification, stakeholder needs generation, and stakeholder needs prioritization. To test this, 18 undergraduate mechanical engineering students were given a stormwater management design vignette; one group was given four stakeholder personas, while the control …

Optimization Of Stamped Tool Geometry Using Regression-Based Cost Models And Structural Constraints, Matthew J. Teague

Mechanical Engineering Undergraduate Honors Theses

Stamped steel paint can openers are simple tools but still require sufficient strength for the end user and low material consumption for the manufacturer. The goal of this project is to optimize the stamped design of a paint can opener by reducing material cost while maintaining structural rigidity and device performance. This was achieved in part by simplifying the tool’s geometry so that an equation for the mass could be developed analytically and checked against the simulation’s outputs. First, a 25-run design of experiments was created that varied the shaft length and the endloop diameter. Next, a CAD model for …

A Multi-Criteria Decision And Spatial Modeling Framework For Socially Informed Advanced Air Mobility Implementation Planning, Noah Wesley Bretz

Graduate Theses and Dissertations

Advanced air mobility (AAM) is an emerging mode of transportation that integrates advanced aircraft technologies, such as manned air taxis or unmanned freight drones, to transport people and goods across urban and regional environments. While these technologies promise to transform mobility, successful implementation depends heavily on community acceptance, which is shaped by multiple social factors. This study presents a multi-criteria decision framework to evaluate and prioritize the key social factors influencing AAM adoption. A literature review identified six primary social factors: safety, noise, privacy and cybersecurity, automation, environmental impact, and price and economics. The Analytical Hierarchy Process (AHP) was used …

An Experimental Study Of The Morphology Of Dna-Carbon Nanotube Hybrid Structures In Direct Dna Sequencing, Avery P. Davis

Biomedical Engineering Undergraduate Honors Theses

Hybrid structures formed between single-stranded DNA (ssDNA) and single-walled carbon nanotubes (SWCNT) have emerged as promising components in future direct DNA sequencing technologies due to their unique morphological and electronic properties. The nanoscale configuration of these hybrids, including the DNA wrapping angle, pitch, and contour behavior, directly influences their potential for stable electronic readout. This thesis presents an experimental study of DNA-SWCNT hybrid morphology using a fixed, reproducible wrapping protocol designed to minimize environmental variability and isolate the influence of DNA nucleotide sequence on hybrid structure. As described in prior work, this protocol produces well-dispersed hybrids suitable for high-resolution imaging. …

In Situ And Operando Microscopy Studies On Lithium Metal Anodes: A Review, Ian Lindsey, Cameron Mondl, Xiangbo Meng

Mechanical Engineering Faculty Publications and Presentations

Lithium metal is regarded as an ultimate anode for rechargeable batteries, ascribed to its extremely high capacity. Its implementation can remarkably boost the energy density of the resultant lithium metal batteries. However, it is very challenging to commercialize lithium metal anodes, primarily due to the intertwined nature of the formation of a solid electrolyte interphase (SEI) and the growth of lithium dendrites. To understand these issues and therefore develop technical solutions, various instrumental techniques have been employed. This review highlights the most recent advancements of in situ and operando microscopy studies that are critical for investigating and addressing the issues …

Unmanned Aircraft Vehicle Safety Reporting And Analysis Of Incidents Utilizing Machine Learning, Cody Harrison

2026 Research Poster Competition

Unmanned Aerial Vehicles (UAVs) are rapidly evolving and being integrated into a wide range of applications, from commercial deliveries to police surveillance and recreational use. As UAVs become more prevalent, the complexity of operations and potential for incidents or accidents will continue to increase. Understanding why these incidents and accidents occur is critical to ensure safe and reliable drone operations as the industry continues to grow. To combat these issues, it is invaluable to analyze UAV incidents quantifiably to identify leading causes and risks in a streamlined and efficient matter. Current manual reporting systems often struggle with the sheer volume …

How Do Different Flight Training Programs Impact Pilot Proficiency?, Abigail Henson

2026 Research Poster Competition

The Federal Aviation Administration (FAA), founded in 1958, ensures safe and efficient use of national airspace by regulating aircraft and pilot certification, setting standards for airports, and managing the National Airspace System. One such regulation is in the certification process for aspiring student pilots. Students who want to obtain their private pilots license can do so by picking either a Part 61 or Part 141 flight school. While both lead to the same certification, these two options differ significantly in terms of structure; Part 61 programs offer flexibility with their individualized approach and fewer requirements while Part 141 schools follow …

Analysis Of Loss Of Engine Power Events In General Aviation, Saloni Satappagol

2026 Research Poster Competition

Among different parts of aviation, general aviation (GA) stands out as one of its largest and most vital sectors. GA is defined as any civil aviation activity excluding scheduled commercial flights and military operations. While loss of engine power is a serious subset of general aviation accidents, accounting for more than 200 fatal accidents per year, several gaps remain in our current understanding of these accidents. While current literature includes older studies from 2000-2014, new data from the past decade have not been analyzed for trends yet. With this significant gap of more than a decade in understanding, it is …

Computational Fluid Dynamics Based Optimization Method Applied To Hydrokinetic Turbine Devices, Stuart Glenn Fletcher

Graduate Theses and Dissertations

This thesis presents a computational investigation of optimal kinematic operating parameters governing various hydrokinetic turbines (HKT) systems for the use of power generation within river and tidal environments. Two separate studies are performed. The first study investigates optimal cycle parameters for simple and complex kinematic modes governing the motion of oscillating foil energy harvesters (OFEH). An iterative gradient-ascent optimization method is used to search for local efficiency optima based on an initial set of kinematic parameters. To search the operational space for up to eight degrees of freedom (DOF), a maximin space filling condition was implemented to efficiently compute initial …

Enhancing Tribological Performance Of Graphite Coatings Through Spray Deposition And Adhesion-Promoting Polydopamine Underlayers, Adedoyin Ayomide Abe

Graduate Theses and Dissertations

Graphite is a widely studied solid lubricant valued for its low friction and layered structure. However, its application as a durable coating remains constrained by poor adhesion to metal substrates and limited wear resistance under sliding. This dissertation presents a systematic approach to overcoming these limitations by integrating deposition process optimization with surface chemistry modification to develop scalable, high-performance graphite coatings. Unlike many prior studies that focus on polished or idealized surfaces, this work targets steel substrates with elevated roughness levels (Sa ≥ 1 μm), aligning with conditions found in practical engineering components. The first phase of research begins by …

Small Laser-Textured Dimples For Improved Tribological Performance Of Cocrmo In Artificial Hip Joints, William Basore Bennett

Graduate Theses and Dissertations

Total hip replacement is a highly successful surgical intervention that restores mobility and improves quality of life for patients with severe joint degeneration. However, the long-term durability of artificial hip joints remains limited by tribological challenges, particularly wear-related failures that can lead to osteolysis and revision surgeries. In metal-on-polyethylene bearing systems, reducing friction and wear at the interface between cobalt–chromium–molybdenum (CCM) femoral heads and ultra-high molecular weight polyethylene (UHMWPE) liners is critical to extending implant lifespan. Laser surface texturing has emerged as a promising technique to improve tribological performance by introducing micro-dimples that enhance lubricant retention and reduce asperity contact. …

Experimental Characterization Of An Additively Manufactured Porous Gyroid Air-Cooled Heat Sink, Grant S. Resler

Mechanical Engineering Undergraduate Honors Theses

This paper presents the development of a ducted test facility designed to evaluate heat sinks efficiency at varying air velocities. This enables the evaluation of both heat transfer and pressure drop performance. These metrics are essential to the overall efficiency of heat sinks and help identify the optimal air velocity to achieve the desired thermal performance. A standard plate fin heat sink was used as a control for comparison to a novel heat sink. The specialized heat sink geometry was generated using nTop, a generative design software focused on additive manufacturing. This design was fabricated via Direct Metal Laser Sintering …

Optimizing Driving Waveforms To Enhance Inkjet Printing Speed, Chao Jan Sui, Wenchao A. Zhou

Mechanical Engineering Faculty Publications and Presentations

Inkjet printing has been extensively employed across various industrial applications due to its capability to produce high-resolution outputs and accommodate a diverse range of materials. However, its printing speed (volumetric printing rate or volumetric productivity) has remained a bottleneck for large-scale manufacturing. This study introduces a new strategy aimed at enhancing the speed of piezoelectric inkjet printing by optimizing waveform parameters. Expanding on our prior work, which analyzed the relationship between driving signal parameters and key factors like droplet volume and jetting frequency, we now focus on optimizing these parameters to maximize printing speed. To establish a fair comparison across …

Electromigration In Eutectic Gold-Tin (80au20sn-Wt%) Solder Joints, Whit Vinson, David Huitink

Mechanical Engineering Faculty Publications and Presentations

Eutectic gold-tin solder joints (80Au20Snwt%) with a diameter of 300 mu m diameter were subjected to electromigration (EM) conditions of 10,000-20,000 A/cm2 in the ambient temperature range of 125-215 degrees C. The present work examines a set of 36 experimental test runs using two different test coupons (18 runs with each coupon type and a total of 90 joints tested). Seven of the 36 coupons survived the maximum test duration period of 500 h. One coupon type created a linear electric current pathway through two lengths of 254-mu m-diameter copper wire connected by a single gold-tin joint. The other coupon …

Interface And Mechanical Properties Of 1d And 1d-2d Carbon Nanomaterials In Copper Matrix, Abigail L. Eaton, Arun K. Nair

Mechanical Engineering Faculty Publications and Presentations

Low-dimensional carbon nanomaterials have unique electron density distributions which warrant their classification as 1D and 2D, and they are useful for a wide variety of nanocomposite applications. This group includes 1D carbyne, which has high stiffness, and a 1D-2D hybrid composed of carbyne and a highly elastic cyclo[18] carbon ring (2D). We use density functional theory and molecular dynamics methods to study the interface properties of carbyne and the hybrid on Cu (111) surface and determine the mechanical properties of nanocomposites comprised of the nanomaterials as a fiber in Cu matrix at varying temperatures. We predict that on Cu (111) …

Advances In Encapsulated Phase Change Materials For Integration In Thermal Management Applications, Muhammad Ghufran, David Huitink

Mechanical Engineering Faculty Publications and Presentations

Encapsulated phase change materials (ePCMs) have the potential to emerge as a key solution for efficient thermal management in various applications. This review paper explores the recent advancements in ePCMs for thermal energy storage and thermal management. We start with a basic overview of the PCMs and then performance enhancements of PCMs through the encapsulation, critical parameters for encapsulation, various encapsulation methods, and their evaluation are discussed. This review also discusses key properties and proposed figure of merit for ePCMs, impact of encapsulation on thermophysical properties, performance evaluation of ePCMs, thermal management needs, and the role of PCMs. The paper …

Durable Low-Friction Graphite Coatings Enabled By A Polydopamine Adhesive Underlayer, Adedoyin Ayomide Abe, Fernando Maia De Oliveira, Deborah Okyere, Mourad Benamara, Jingyi Chen, Yuriy I. Mazur, Min Zou

Mechanical Engineering Faculty Publications and Presentations

This study investigates the tribological performance and wear mechanisms of graphite and polydopamine/graphite (PDA/graphite) coatings on stainless steel under dry sliding conditions. While graphite is widely used as a solid lubricant, its poor adhesion to metal substrates limits long-term durability. Incorporating an adhesion-promoting PDA underlayer significantly improved coating lifetime and wear resistance. Tribological testing revealed that PDA/graphite coatings maintained a coefficient of friction (COF) below 0.15 for over seven times longer than graphite-only coatings. High-resolution scanning electron microscopy, SEM, and profilometry showed that PDA improved coating adhesion and suppressed lateral debris transport, confining wear to a narrow zone. Surface and …

Thermally Stabilized Polyacrylonitrile For Flexible Triboelectric Devices Operating From-29 °C To 400 °C, Yide Zheng, Rongfeng Mao, Beilei Liu, Bo Ma, Wei Li, Yue Sun, Wan Shou

Mechanical Engineering Faculty Publications and Presentations

Extreme temperature wearable technology enables unique applications in extreme conditions, such as physiological indicators (body temperature and heart rate) monitoring, which can provide timely warnings of health risks associated with unusual high and low temperatures. However, most soft materials used for wearable devices, including both sensors and power suppliers, are severely affected by high temperature, limiting their applications. Here, we reported a flexible triboelectric material for extreme temperature application, ranging from-29 degrees C to 400 degrees C. The device consists of a thermally stabilized polyacrylonitrile (TS-PAN) as negative triboelectric material and a mica film as positive triboelectric material. This triboelectric …

Analysis And Predictive Modeling Of Stall And Spin Accidents In General Aviation Fixed-Wing Aircraft, Mehedi Hasan

Graduate Theses and Dissertations

Stall and spin accidents represent a persistent safety concern in General Aviation, with approximately 41% resulting in fatalities despite their relatively low occurrence. This study analyzes 1,079 General Aviation stall and spin accidents from 2008 to 2023 using the National Transportation Safety Board accident database. Our analysis identified the top phases of flight, injury outcomes, and causal factors in stall/spin accidents. Findings indicate that over 93% of stall/spin events involved General Aviation aircraft, with most accidents occurring during initial climb, takeoff, or low-altitude maneuvering. Pilot-related control errors, especially poor airspeed and angle-of-attack management, were the most common causes. To assess …

Engineered Interfaces For Enhanced Transient Liquid Phase Bonding In Electronics Assembly, John Russell Harris

Graduate Theses and Dissertations

Growing applications in transportation make power density a key optimization target in the power electronics industry. More power in a shrinking environment leads to high heat flux and junction temperatures that damage silicon-based switching devices. Temperatures approaching 175℃ can result in false triggering of the device’s activated state, resulting in short circuits. Developing wide bandgap semi-conductors, such as gallium nitride and silicon carbide, are less susceptible to this complication as the energy from elevated temperature is a smaller fraction of what would be required to trigger the device. These devices are projected to function reliably in environments of up to …

Photochemical Fabrication And Tribological Evaluation Of Hexagonal Grooves With Corner Dimples On Cast Iron Surfaces, Steven Sonntag

Graduate Theses and Dissertations

The traditional honing process used to texture cylinder liners in internal combustion engines has long been recognized as suboptimal, as evidenced by the need for a break-in period before achieving peak performance. Although laser-based methods can produce micro-scale features with high precision, they are often cost-prohibitive and difficult to scale for large or complex components. This study explores photochemical machining (PCM) as a low-cost, scalable alternative for fabricating high-resolution surface textures—specifically, hexagonal grooves with corner dimples—on gray cast iron. The resulting textures exhibit uniform groove widths (~13 μm) and varied depths, demonstrating PCM’s capability to create high-resolution patterns with sub-micron …

High-Resolution Energy Efficient Selective Laser Sintering Of Copper Nanoparticles, Bo Shen

Graduate Theses and Dissertations

Copper (Cu) is widely utilized in electronics and photonics applications due to its outstanding electrical and thermal conductivity. With increasing demand for miniaturization and higher precision in modern manufacturing, traditional selective laser sintering (SLS) techniques designed primarily for high-throughput production are becoming insufficient. These conventional methods struggle to deliver the resolution required for micro-scale fabrication and often cause thermal damage to sensitive substrates. Therefore, there is a growing necessity to develop compact and high-resolution laser sintering systems capable of precise microfabrication with minimal thermal influence. This study addresses this challenge by investigating nanosecond pulsed laser sintering as a method to …

Design, Modeling, Control, And Analysis Of A Modular Two-Wheeled Self-Balancing Robotic System, Mishek Jair Musa

Graduate Theses and Dissertations

Two-wheeled self-balancing robots have garnered substantial attention within the realms of research and innovation in academia and industrial settings. In particular, advances in control algorithms, machine learning, reinforcement learning, and sensor technologies have played a pivotal role in their development. Although primarily recognized for their utility in personal transportation in the commercial sector, these robots possess potential applications across various domains, including search and rescue, healthcare, material handling, logistics, etc., due to their active stabilization and exceptional maneuvering capabilities. A particular area of interest lies in the creation of modular self-balancing robots designed for seamless reconfiguration and enhanced human interaction. …

Tribology Of Textured Surfaces, Min Zou, Mahyar Afshar-Mohajer, Robert A. Fleming

Mechanical Engineering Faculty Publications and Presentations

Surface texturing has emerged as a transformative approach to improving friction, lubrication, and wear across a wide range of mechanical components. From bio-inspired micro-dimples to engineered macro-grooves, texture designs are increasingly applied in biomedical implants, bearings, seals, and automotive systems. This Special Issue, “Tribology of Textured Surfaces,” compiles 14 papers that collectively cover fabrication techniques, multi-scale optimization, predictive modeling, and diverse application areas.   The following sections summarize the major themes of this Special Issue. Section 2 reviews the fabrication techniques and texture scales addressed by the authors. Section 3 examines modeling and numerical studies, while Section 4 categorizes the work …

Oscillatory Flow Improves Hydrodynamic Ordering Of Soft Suspensions In Rectangular Channels, Paul C. Millett

Mechanical Engineering Faculty Publications and Presentations

A computational study is presented that examines the hydrodynamic ordering of soft-particle suspensions within rectangular channels undergoing both steady and oscillatory flow. In these conditions, particles assemble into one-dimensional train-like configurations aligned in the flow direction. The results indicate that oscillatory flow facilitates a significant improvement in the ordering process, particularly for the assembly of multiple side-by-side trains within the channel. Several key parameters are systematically varied, including the Wolmersley number (Wo) representing the oscillatory frequency, the capillary number (Ca) representing the particle deformability, and the particle volume fraction (phi). It is found that optimal ordering occurs for a particular …