Engineering Commons^™

Sensing Negative-Cone Rotational Diffusion Of Dipole-Like Emitters, Yuanxin Qiu, Kaizhi A. Nie, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Fluorescence anisotropy and single-molecule orientation-localization microscopy (SMOLM) are powerful techniques that quantify the rotational diffusion of dipole-like emitters, which is important for sensing molecular interactions and chemical environments at the nanoscale. Numerous theoretical and experimental studies have thoroughly characterized single-molecule rotations even when those rotations are much faster than the detector integration time. Here, we extend the theory of measuring rotational diffusion to situations where a single dipole rotates uniformly everywhere outside of an isotropic cone of a certain size, termed a negative cone. This scenario corresponds to negative fluorescence anisotropy 𝑟 and has been observed in emitters exhibiting strong …

Interfacial Engineering Of Electrodes And Solid-State Electrolytes For High-Performance Lithium-Ion And Sodium-Ion Batteries, Ahmad Helaley

McKelvey School of Engineering Graduate Student Theses & Dissertations

The rapid expansion of electrified transportation and renewable energy integration demands advanced lithium-ion (Li-ion) and sodium-ion (Na-ion) batteries with enhanced safety, long-term reliability, and high energy efficiency. However, conventional systems employing liquid electrolytes continue to exhibit persistent failure modes, including thermal instability, parasitic interfacial reactions, transition-metal dissolution, and electrode degradation under high-voltage or fast-charging conditions. These limitations become even more critical in solid-state configurations, where insufficient ion mobility and interfacial incompatibility can severely restrict electrochemical performance. The first part of this dissertation develops an atomic-layer-scale interfacial stabilization strategy using atomic layer deposition (ALD) coatings. ZnO-modified graphite anodes in Li-ion cells …

Neuromodulation In Olfactory Networks: Inferring Circuit Motifs And Predicting Behavioral Outcomes From Neural Response Changes, Yelyzaveta Bessonova

McKelvey School of Engineering Graduate Student Theses & Dissertations

Many organisms rely on olfaction to navigate their environment in response to surrounding chemical cues. Within the olfactory system, first, external signals are transduced into neural activity patterns that drive a diverse array of behavioral responses. However, sensory processing alone does not fully account for this variability. Fluctuations in neuromodulator levels are equally critical in shaping how olfactory information is encoded and translated into behavior. The goal of this dissertation is to investigate how changes in the neurochemistry within the olfactory circuit influence neural signaling and, ultimately, behavioral responses. To achieve this, I investigated how three neuromodulators: serotonin, dopamine, and …

Evaluation And Calibration Of Coupled Low-Cost Particulate Matter Sensors, Tyler Cargill

McKelvey School of Engineering Graduate Student Theses & Dissertations

Low-cost sensors (LCS), if used appropriately, are useful instruments to elucidate human exposure to particles suspended in the air (i.e. particulate matter, PM). Characterizing this exposure is crucial, as exposure to PM2.5 (i.e. particles with aerodynamic diameter ≤ 2.5 μm) negatively affects the respiratory, cardiovascular, and other organ systems and is the leading environmental burden for global mortality. Similarly, exposure to particles with aerodynamic diameters greater than 2.5 μm and less than or equal to 10 μm, here forth termed as PMCoarse, is known to cause health ailments for the upper respiratory system. This dissertation focuses on the MODULAIRTM-PM (MOD-PM), …

Probing The Mechanisms Of Reinforcement Learning: Reinforcement Learning, Ventral Striatal Astrocytes, And The Dynamic Coordination Of Information Seeking With Learning, Fatih Sogukpinar

McKelvey School of Engineering Graduate Student Theses & Dissertations

While reinforcement learning has been a vital component in artificial intelligence and machine learning, there exist many open questions about its implementations and how to improve them, in both minds and machines. Among these are i) the contribution of non-neuronal cell types to reinforcement learning, and ii) information-seeking behavior during reinforcement learning. In this thesis, we studied these main topics pertaining to reinforcement learning. In the first chapter, we examined the role of astrocytes in reinforcement learning, and in the second, we investigated human information seeking during reinforcement learning. Neurons in the human and animal brain have been known to …

Transforming Co2 Into Value-Added Products: Liquefied Petroleum Gas And Solid Carbon Materials, Kaiying Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

The escalating climate crisis, driven by anthropogenic carbon dioxide (CO2) emissions, necessitates the development of advanced Carbon Capture and Utilization (CCU) technologies. A critical distinction within CCU lies between transient carbon cycling, which converts CO2 into fuels, and permanent sequestration, which transforms it into durable, solid materials. This dissertation addresses fundamental catalytic challenges across both pathways to develop economically viable and technologically sound solutions for CO2 valorization. This work seeks to answer two primary research questions: (1) How can the catalyst temperature mismatch and stability limitations in the tandem conversion of CO2 to Liquefied Petroleum Gas (LPG) be overcome to …

Optimization Of Research Pipeline To Characterize The Effects Of Atp-Sensitive Potassium Channels Mutations On Native Skeletal Muscle Fibers And Evaluate Potential Drug Therapy, Yuezhou Chen

McKelvey School of Engineering Graduate Student Theses & Dissertations

The ATP-sensitive potassium (KATP) channel is a critical metabolic sensor in skeletal muscle, yet its definitive molecular composition and functional roles remain contested. In this study, I conclusively demonstrate that the Kir6.2/SUR2 complex forms sarcolemmal KATP channel in mouse fast-twitch muscle. Genetic knock-out (KO) of Kir6.2 (Kcnj11−/−) or SUR2 (Abcc9−/−) resulted in a similar phenotype with increased fatigue resistance and a pathological rise in unstimulated resting tension at high-frequency stimulation. In contrast, SUR1 (Abcc8−/−) KO was ineffective. Furthermore, a CRISPR/Cas9 knock-in mouse model of a human SUR2A truncation variant (KCGV/KCGV) recapitulated the abnormal force accumulation, demonstrating that even loss-of-function of …

Development Of A Multispectral Collagen Detection Dermatology Device For Delineation Of Non-Melanoma Skin Cancers, Anmol Jarang

McKelvey School of Engineering Graduate Student Theses & Dissertations

To diagnose and manage skin disease, clinicians primarily use visual inspection aided with dermatoscopes, which are cross-polarized magnifiers. In recent years, digital cross polarized multispectral imaging systems have been developed to quantitatively assess skin disease. For example, systems like the one developed by Yaroslavsky et al., which utilize red and blue filters, can non-invasively assess the collagen network in the dermis(Yaroslavsky et al., 2003). Visualization of collagen network disruption can make it easier to visualize the boundaries of skin cancers like keratinocyte carcinoma, and therefore easier to excise completely. Current systems use external bandpass filters in front of cameras to …

Enhancing Aerosol Scattering Measurements: Performance Evaluation And Quality Assurance Of Airphoton Integrating Nephelometers In The Surface Particulate Matter Network, Kamlendra Singh Pathak

McKelvey School of Engineering Graduate Student Theses & Dissertations

Integrating nephelometers are key instruments for quantifying aerosol light scattering, a fundamental parameter governing the direct radiative effect of aerosols on climate and visibility, and for interpreting satellite observations of aerosol optical depth. The AirPhoton integrating nephelometer quantifies aerosol light scattering by measuring total scattering from the sample air and subtracting a clean-air reference that represents Rayleigh scattering, instrument wall scattering, and detector background noise. Measurement accuracy depends on rigorous calibration and regular performance evaluation to account for instrumental drift and environmental influences. This study presents a field performance evaluation of the AirPhoton integrating nephelometer within the global Surface Particulate …

Expansion Limits Of Meshed Split-Thickness Skin Grafts, Haomin Yu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Split-thickness skin grafts are widely used to treat chronic wounds. Procedure design requires surgeons to predict how much a patch of the patient's own skin expands when it is meshed with rows of slits and stretched over a larger wound area. Accurate prediction of graft expansion remains a challenge, with current models overestimating the actual expansion, leading to suboptimal outcomes. Inspired by the principles of mechanical metamaterials, we developed a model that distinguishes between the kinematic rearrangement of structural elements and their stretching, providing a more accurate prediction of skin graft expansion. Our model was validated against extensive data …

Integrating Large Language Models And Single-Cell Omics Analysis For Target Discovery In Pancreatic Ductal Adenocarcinoma, Zixi Xu

McKelvey School of Engineering Graduate Student Theses & Dissertations

The elucidation of cell-type–specific signaling networks is central to understanding pancreatic ductal adenocarcinoma (PDAC) and to nominating mechanistically grounded therapeutic targets. We present a Text-to-Target framework that integrates large language models (LLMs) with single-cell omics to couple literature-derived hypotheses to cell-type–resolved expression evidence. Using publicly available datasets, we construct malignant ductal epithelial and lineage-matched acinar meta-cell cohorts from PDAC and perform differential expression analysis to obtain a robust catalogue of disease-associated transcriptional changes. In parallel, an ensemble of LLMs is prompted in a schema-constrained manner to retrieve cell-type–specific targets, pathways, and mechanistic annotations from the biomedical literature. After normalization and …

Fpga-Accelerated Computational Photon Counting, Chibueze Onyeador

McKelvey School of Engineering Graduate Student Theses & Dissertations

Fluorescence Lifetime Imaging Microscopy (FLIM) is a powerful tool for biomedical re- search. It leverages fluorescence of biological samples to visualize and characterize biological dynamics and molecular interactions. FLIM utilizes fluorescence lifetime, the average time a molecule stays in its excited state after absorbing a photon, to investigate the dynamics of biological samples.

Ultra-fast and precise (ps-ns) timing fluorescence acquisition techniques suffer from different trade-offs. Some methods suffer from high dead times, decreased accuracy in fluorescence lifetime calculations, and high data volumes and transfers. Finding a new method that can provide the best performance while experiencing low dead times, adequate …

Functional Characterization Of Abcc8 Mutations Potentially Linked To The Transition From Hyperinsulinemic Hypoglycemia To Diabetes, Hao Zhang

McKelvey School of Engineering Graduate Student Theses & Dissertations

ATP-sensitive potassium (KATP) channels, composed of the SUR1 and Kir6.2 subunits encoded by the ABCC8 and KCNJ11 genes, are critical regulators of membrane excitability and insulin secretion in pancreatic β-cells. Gain-of-function (GOF) mutations in these genes cause neonatal diabetes mellitus through impaired insulin secretion and persistent hyperglycemia, whereas loss-of-function (LOF) mutations lead to congenital hyperinsulinism (CHI) with hypoglycemia due to β-cell hyperexcitability. I have addressed a paradoxical form of maturity-onset diabetes of the young (MODY) arising from KATP mutations, in which patients transition from CHI to glucose intolerance later in life. My experiments indicate that many KATP mutations associated with …

Tests Without Borders: A Global Approach To Measuring Visualization Literacy, Olivia A. Guess

McKelvey School of Engineering Graduate Student Theses & Dissertations

Visualization literacy assessments shape how we understand people's ability to interpret data, yet most existing instruments embed Western datasets and assumptions that limit their relevance for global audiences. This thesis argues that because data is personal, assessments must also be culturally grounded. We introduce a unified framework for adapting the Mini-VLAT into 22 regionally responsive short-form assessments, each retaining the structure of the original test while incorporating datasets and scenarios tailored to specific regions around the world. To demonstrate how such adaptations can be customized and validated, we present a detailed case study of a Ghana-adapted Mini-VLAT, developed in collaboration …

2d-Nanosilicate Carriers For Sustained Delivery Of Vaccine Components, Chih Yun Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Laponite® 2D Nanosilicates (NS) are disc-shaped platelets (~30 nm diameter, ~1 nm thick) with positively charged edges and negatively charged faces, capable of loading proteins, drugs, and nucleic acids via electrostatic interactions to form a house-of-cards gel that sequesters cargo. Here, we evaluated NS for sustained delivery of antigens and Toll-like receptor (TLR) agonists to extend germinal center duration and enhance antibody quality. The model antigen ovalbumin (OVA) was adsorbed onto NS at acidic pH in a ~1:1 ratio, with partial unfolding that remained stable at physiological pH. NS-OVA complexes were efficiently internalized by dendritic cells, with uptake driven primarily …

Iphone-Based Image Refocusing, Katie Jeong, Daniel Niu

Electrical and Systems Engineering Capstone Design Projects

In this project, we show that we can change the focus of a picture after we take it by using real optical physics instead of fake software blur. Modern phones try to create “portrait mode” effects, but those results are often not physically correct. Our approach uses multiple photos taken from slightly different positions to figure out the directions that light rays came from in the scene.

To collect the photos, we move an iPhone sideways on a slider in small, precise steps. Since we know exactly how far the phone moved for each picture, we can track how objects …

The Effect Of Fascicular Elastin On The Mechanical And Functional Properties Of Healthy, Damaged, And Healing Tendon, Shawn Pavey

McKelvey School of Engineering Graduate Student Theses & Dissertations

Mechanical properties of tendon are highly influenced by structural protein composition and microscopic sub-structures. Within the largest subunit of tendon, the fascicle, the role of the elastin protein remains understudied despite impressive extensibility and fatigue resistance of its resulting elastic fibers. While previous work catalogued contributions of fascicular elastin across tendon type and species, the anticipated effects of elastin in fatigue and healing have not yet been explored. While previous knockout mouse models showed that disruption of elastic fibers led to altered mechanical properties (e.g., increased linear modulus), these models depended on heterozygous elastin deficiency or indirect knockout of proteins …

Mems 4110: Arduino-Controlled Precise Water Distribution System, Jack M. Williams, Joe Sieracki, Nina Woodward

Mechanical Engineering Design Project Class

Christina Youngepeter is a Graduate Student of Archaeology at Washington University in St. Louis. She is studying an ancient plant that fell out of use after 1400 CE, whose ideal watering conditions are lost to time. To better characterize the plant, Christina is running an experiment to determine the ideal watering conditions for plant development. This involves watering sets of the plant with different volumes of water twice a day. The different volumes of water received by the groups of plants are 933 mL, 833 mL, 733 mL, 617 mL, 517 mL, and 417 mL. The acceptable percent error in …

Mems 4110: Trash-E (Terrain-Adaptive Remote Autonomous Sanitation Hauling Engineer), Jackson R. Weisbard, Raza Rabbani, Dhruv Goel, Kj Kernan

Mechanical Engineering Design Project Class

The TRASH-E (Terrain-Adaptive Remote Autonomous Sanitation Hauling Engineer) project was created to compete in the 2025 ASME Student Design Challenge. For 2025, the ASME SDC asked for the development of a remotecontrolled robot that could collect and deposit trash from receptacles placed around a miniature city. The robot had to adhere to specific size and weight constraints, as well as obey traffic laws in the same manner as a real driver operating a motor vehicle.

Mems 4110: Air Hockey Table Physics Education Exhibit, Olaoluwa J. Adeniji, Salomon Dessalines, Gyvnn Mendenhall

Mechanical Engineering Design Project Class

This project centers on creating an educational air-hockey exhibit designed for use in a science museum. The goal of the device is to transform a familiar game into a hands-on demonstration of basic physics and engineering concepts such as motion, momentum, energy transfer, and impact forces. Through discussions with our customer, Professor Potter, we established that the exhibit must balance two priorities: it must be fun and intuitive for visitors of all ages, and it must provide meaningful real-time feedback that helps users understand the science behind the experience.

Mems 4110: Asme Waste Collection Challenge, Leslie Alfaro, Cathy Zhao, Bari Diamond, Obike Anwisye

Mechanical Engineering Design Project Class

For this project, our goal was to design and build a remote-controlled wastecollection robot that could pick up trash bins and deliver their contents to a dumpsite while staying within the strict rules of the ASME challenge. The robot had to fit inside a 50 cm cube, drive through six-inch lanes, follow traffic rules, and be fully controlled by a six-channel RC controller. These constraints shaped almost every decision we made throughout the design process.

Mems 4110: Improving Restaurant Efficiency: Automatic Egg Peeler, Shanice Isimbi Mutabazi, Kyle Bryant Okui, Max Ari Siefert, Lani Fancesca Espinel

Mechanical Engineering Design Project Class

Neon Greens is a salad restaurant in St. Louis, MO that focuses on serving fresh, locally sourced ingredients. One of their signature menu items includes soft and hard-boiled eggs, which are used in large quantities every day. Currently, these eggs are peeled by hand, which can be slow, inconsistent, and difficult to keep up with during busy hours. Because of this, Neon Greens needs a faster and more reliable way to peel eggs without increasing labor. Our project aims to design a device that can peel eggs automatically, reduce prep time, and stay safe and easy to clean in a …

Mems 4110: The Egg Peeler, Susanna Yeh, Jessica Arnold, Peter Nesin, Finn Mcnamee

Mechanical Engineering Design Project Class

The purpose of this project is to assist the customer Neon Greens in accelerating their food preparation time by designing an egg peeler device. To have a better understanding of the customer needs and expectations, the design team participated in an interview with Neon Greens to address their vision and desires for this device. For the semester-long project, the team underwent various prototype stages, including the proof of concept, the initial prototype, and the final prototype. Our final design consists of a hopper that holds a batch of eggs on top and drops two eggs at a time, one on …

Mems 4110: Science Museum Bernoulli's Demo, Emma Sloan, Carter Hahnfeldt, Luke Mccann

Mechanical Engineering Design Project Class

This report outlines the design and prototyping process of the Science Museum Bernoulli’s Demo (SMBD), a capstone project for MEMS 4110 Senior Design Project at Washington University in St. Louis. The SMBD is a fun game for a children’s science museum designed to demonstrate how the exit velocity of water from a pipe changes based on the pipe diameter. The design intends to teach kids about Bernoulli’s principle by allowing them to choose from two different sized pipes to spray water at a target. The key aspect of the game is that the water flows more slowly out of the …

Mems 4110: Precise Water Distribution System, Morelia R. Reyes-Perez, Jp Torack, Jakob Ayala

Mechanical Engineering Design Project Class

This project focuses on designing and prototyping an automatic precise watering system to support plant research conducted in the Washington University greenhouse. The customer, graduate student Christina Youngpeter, needs a reliable method for delivering accurately measured water volumes to individual plants as part of a study on hydration effects. Manual watering can be time consuming, our system will provide a programmable, repeatable, and low maintenance solution.

Mems 4110: Interactive Racecar Dynamics Exhibit, Leonardo Gomes, Hunter Rocker, Joseph Norris, Jack Coode

Mechanical Engineering Design Project Class

Visitors at science museums often struggle to understand how launch speed, lane choice, and banked-curve dynamics influence a car’s trajectory. Existing educational exhibits rarely provide repeatable measurements or clear physics demonstrations. This project addresses that gap by creating an interactive racecar dynamics exhibit with a controlled launcher, 3D-printed banked track geometry, and optical timing gates. The goal is to give users measurable feedback on velocity, lane behavior, and motion through a 31° banked turn while maintaining safety, durability, and fast reset time for continuous hands-on learning.

Mems 4110: Soft Boiled Egg Peeler, Nina Fischer, Ruth Mellin, Jack Salamon, Malaya Hill

Mechanical Engineering Design Project Class

This report outlines the design and evaluation of a hard-boiled egg–peeling device developed for the Saint Louis restaurant Neon Greens. The restaurant prepares an average of 150 soft-boiled eggs daily for dishes such as the Protein Salad. They requested a device able to autonomously peel 150 eggs per hour with minimal employee involvement.

Mems 4110: Rapid Drink Chiller, Aidan F. Moriarty, John Babineau, Levi Gingerich, Quinn Close

Mechanical Engineering Design Project Class

The purpose of this document is to outline the purpose and function of the rapid drink chiller device. This device is designed to replace traditional portable drink cooling methods, such as traditional styrofoam coolers, fridges, etc. Traditional methods require the transport and inclusion of ice, and require overly long cooling times, with the exception traditional fridges which are non-portable. The rapid drink chiller is designed to be light and compact in order to maximize transportability, accomplished via an all foam insulation construction around a waterproof box. The box is filled with a water-ethanol solution which is cooled to extremely low …

Mems 4110: Precise Water Distribution System, Fadhimah Mohamed, Duyen Nguyen, Citlalli Sanchez-Ayala

Mechanical Engineering Design Project Class

Greenhouse research requires precise, repeatable watering to maintain consistent experimental conditions. As plant counts scale to 150–360 pots, manual watering becomes inefficient, inconsistent. This project aims to design an automated irrigation system that reliably delivers controlled water volumes to an initial set of 36 pots, operates under greenhouse conditions with minimal user intervention, and provides a scalable foundation for future expansion.

Mems 4110: Egg Peeler Group L1, Brian Hau, Alex Kenn Lee, Aisha Bah, Shanaelle Nabatmama

Mechanical Engineering Design Project Class

Neon Greens is a quick-serve salad concept located in St. Louis, MO. Part hydroponic farm and
part restaurant, they focus on growing a majority of their greens in-house, and emphasize
transparency in food systems.
In recent months, they added a ‘Protein Caesar’ salad to the menu. That salad features two
‘jammy’ boiled eggs which are cut in half. Staff at Neon Greens steam eggs precisely in their
Combi oven and shock them to stop the cooking process. They then peel those eggs by hand.
On some days, they must process >100 eggs, which can take up to 1.5 hours of …