Engineering Commons^™

Novel Polymer-Derived Ceramic Antennas For Hypersonic Applications, Peter J. Alley

Masters Theses

With recent advances in three dimensional [3D] printing of polymer-derived ceramics [PDCs], and the controllability of electrical continuity thereof, interest has risen in potential applications resultant from these techniques in the realm of radio communication, particularly in cases where extreme high temperatures are ambient. The following investigates the electrical properties of both insulating and conductive variants of these PDCs, the interaction between each, and the performance characteristics observed when combined using microstrip antenna design theory for high temperature applications.

Evtol Delivery Drone, Caleb Nass, Brennen Bazaldua, Matthew Mason, Dylan Cummings, Derek Ren

2024 Symposium

The creation of online food ordering and delivery is an invention that has introduced a completely new market with the potential for innovation. Traditional methods of delivery currently focus on individual delivery drivers. But this method depends on variables like traffic and road conditions and uses considerable amounts of fuel while incurring prohibitive costs to employers, which may be impractical for small businesses. To that end, our team’s project seeks to design and fabricate a 3D printed eVTOL delivery drone capable of vertical takeoff and landing along with transition to horizontal flight. We believe that our design will be lightweight, …

Capstone Review: Filament Unit Multiplexing Engine, Gal Cohen

University Honors Theses

The Filament Unit Multiplexing Engine (FUME) is a Mechanical Engineering capstone project sponsored by Portland State University's Electronic Prototyping Lab (EPL). The project addresses the need for an automated system to manage 3D printing operations. The current manual process of selecting and routing a spool of filament to one of the available 3D printers is labor-intensive and limits the efficiency of the lab's 3D printing farm. FUME aims to create a custom solution tailored for a multi-user, multi-spool, and multi-printer environment. The designed system includes key components: a spool holder, an engine, a track and shuttle system, and a funnel. …

The Effect Of Atomic Oxygen On Additively Manufactured Materials, Ryan Grogan

Master's Theses

Additive manufacturing (AM) is a rapidly developing manufacturing method utilized in fields such as the aerospace industry. In-space AM is a technology of interest for the future of spaceflight, including on-orbit manufacturing. However, AM materials are subject to defects that may impact their performance in space-based applications. How these defects change the material’s reaction to the space environment, specifically atomic oxygen (AO), has only recently been explored. AO is a highly corrosive, dominant constituent in low Earth orbit that causes continuous erosion of spacecraft surfaces. The effect of AO on various AM materials is investigated in this thesis. Stainless steel, …

Engineering Of Functional Hybrid Nanocomposites For Renewable Energy Applications Via Laser Ablation, Mahshid Mokhtarnejad

Doctoral Dissertations

Carbon-based hybrid nanocomposites (HNCs) have increasingly gained prominence in the materials science community due to their widespread applications in advanced energy storage and conversion devices. Yet, current, and conventional methods to synthesize tailored HNC structures involve complex and multi-step processes that often require harsh chemical reagents. To address the majority of these shortcomings, this thesis proposes Laser Ablation Synthesis in Solution (LASiS) as a rapid, inexpensive, and facile technique for synthesis of Metal-Organic Framework (MOF)–derived and Metal Oxide/reduced Graphene Oxide (rGO) HNCs in an environmentally friendly fashion. These engineered composite nanomaterials show superior properties as (1) non-precious medal based electrocatalysts …

Additive Manufacturing Of Porous Tungsten Carbide Structural Electrode Components Using Robocasting, James Bevis

All Theses

Thanks to ideal mechanical and electrochemical properties, Tungsten Carbide (WC) shows excellent potential as a structural electrode material for multifunctional devices. These devices have applications in electric vehicles, for example, structural fuel cells and massless batteries. In such a context, structural WC electrodes will also benefit from porosity to decrease their weight and increase their surface area and chemical reactivity. Porous WC is a useful material for this field because of its high strength-to-weight ratio and electrical properties. However, current manufacturing methods can be expensive, complex, and limited, so the intent is to provide a more simplistic and sustainable method …

The Effect Of Extended Saltwater Absorption And Uv Cure On The Compressive Properties Of Msla 3d-Printed Photopolymer Resin Samples With Printing Variations, Suzanne Dixon

Theses and Dissertations

Liquid Crystal Display (LCD) 3D printers, also known as Masked Stereolithography Apparatus (MSLA), is a type of vat polymerization printing technique that cures liquid resin into a solid object. This technique is relatively new. Consequently, there is a shortage of detailed research on the impact of long-term environmental exposure on the MSLA-printed materials. The research within this document informs engineers and scientists of resin compressive properties after extended exposure to saltwater and ultraviolet (UV) light. Saltwater absorption of the material was analyzed at atmospheric pressure, 30-psi, 60-psi, and 90-psi; the samples reached saturation in saltwater after 56 days. The variation …

Research On 3d Printing Resin Exposure Properties And Its Application On Centrifugal Microfluidic Platform Based On Fluorescence Detection, Zheng Qiao

LSU Doctoral Dissertations

This dissertation encapsulates significant advancements in the field of SLA 3D printing and centrifugal microfluidics. Central to the research is the development of a novel mathematical model for predicting trapped resin thickness in SLA 3D printing, a groundbreaking contribution that addresses a critical aspect of printing intricate structures. This model, the first to establish a mathematical relationship for resin thickness, is rooted in a comprehensive study of the resin curing process. The research leverages the concept of 'critical dosage' for resin curing, leading to a more refined and theoretically grounded approach for calculating curing thickness. Experimentation further validates the model, …

Directional Dependent Fracture Characteristics Of 3d Printed Mechanical Metamaterials, Thomas Draper

Dissertations, Master's Theses and Master's Reports

Structural metamaterials, such as lattice metamaterials, are engineered cellular structures designed to achieve properties not achievable by natural materials. They enable mechanical properties unattainable by homogeneous solid materials and offer optimal properties for these materials tunable for specific applications in industries such as automotive, medical, and aerospace. Recent findings have revealed unique tunable mechanical properties such as negative Poisson's ratio, high strength-to-weight ratio, anisotropic stiffness, and much more. While the elastic and wave propogation properties of many lattice metamaterials are well investigated, the fracture properties are not well explored. However, their low fracture toughness is a bottleneck for their use …

3d Printed Drone (Body And Controls), Michael Dick, Hayden Pinkelman, Tanner Henderson, Logan Prince

Williams Honors College, Honors Research Projects

The objective is to build a scaled down model of a 3D printed drone capable of carrying a payload scalable to 50 lbs. for a wide array of applications. Some applications of the drone could include delivering support materials during natural disasters, such as foam to put out fire or medical aid packs to provide aid to injured people, food or package delivery, or military applications. The project has been split up into two groups. One group will be focusing on the propulsion aspect of the project, such as the electric motors and airfoil. Simultaneously, this group will design the …

Infant Molds For Cleft Deformities, Hannah Brunow, Drew Reinbolt, Rhonda Troyer, Christian Miller

Williams Honors College, Honors Research Projects

Cleft lip and palate are very common birth defects where the roof of a baby's mouth and lip do not form properly while in the womb. Babies born with cleft lip or palate can undergo surgery after going through a process to make the initial gap smaller through incrementally smaller, retainer-like appliances. We will be trying to find a way to improve the pre-surgery process by implementing 3D printing. We will be performing this research for a craniofacial orthodontist at Akron Children's Hospital. We hope that our success will lead to a decrease in the amount of time spent making …

Robot-Based 3d Printing, Aaron Hoffman

Williams Honors College, Honors Research Projects

Details of a large-format 3D printer created to print experimental materials, test multi-axis print techniques, and quickly print large objects. The printer consists of a 7-axis robotic arm and pellet extruder, which are controlled by a PC. Experimental materials such as recycled polymers or carbon-fiber reinforced materials can be easily tested with the pellet format of the extruder. The printer can perform different printing techniques and can be used to experiment with material properties when using these techniques with different polymers. The print surface is around 5 times larger than the average commercial 3D printer, and the robotic arm provides …

Materials Testing For Large Format 3d Printing, William Jenkins

Williams Honors College, Honors Research Projects

An ABS Carbon Fiber blend was printed into single walled hexagons at a variety of settings on a Cincinnati BAAM large format 3D printer. These hexagons were then cut down into sheets and had tensile and flexural test samples cut out of them, in order for materials testing to be performed. Tensile strength, tensile strain, young’s modulus, flexural strength, deflection and elastic modulus were all determined. A desktop CNC machine and a planer were purchased for the manufacturing of these samples, and an efficient cutting procedure was designed and optimized. After all data collection concluded, this data was thoroughly analyzed, …

Functional Verification Of Additively Manufactured Metallopolymer Structures For Structural Electronics Design, Nathan D. Singhal

Honors Undergraduate Theses

As an attempt to improve the overall cost-effectiveness and ease of structural electronics manufacturing, this study characterizes the mechanical and electrical responses of structures which are fabricated from a novel metallopolymer composite material by fused deposition modeling as they are subjected to quasi-static, uniaxial mechanical tension. Baseline values of tensile properties and electrical resistivity were first obtained via ASTM D638-22 standard testing procedures and linear sweep voltammetry (LSV), respectively. A hybrid procedure to measure in-situ mechanically dependent electrical behavior was subsequently developed and implemented. The mechanical and electromechanical testing was followed by the derivation of stochastic values for several mechanical …

Removal Of Residual Stress In 3d Printed Polymers, Christian Jenkins

Williams Honors College, Honors Research Projects

This project aims to investigate the relationship between stress relaxation and the reduction of dimensional shrinkage and warping in 3D printed polymers produced through fused filament fabrication. The hypothesis suggests that residual stress in 3D printed structures results from factors such as temperature differences, molecular-level contributions, and rapid cooling, causing post-printing warpage and damage. To mitigate these issues, the project proposes annealing 3D printed polymers in a hot sandbath to allow stress relaxation without warping. The study will employ a Dynamic Mechanical Analysis (DMA) machine to assess mechanical properties of relaxed and unrelaxed samples, comparing their effectiveness. The project's timeline …

Early-Age Strength And Failure Characteristics Of 3d Printable Polymer Concrete: Numerical Modelling And Experimental Testing, Mohammad Amin Dehghani Najvani

Civil Engineering ETDs

The time-dependent rheological and early-age strength parameters of Polymer concrete (PC) were investigated. PC flow decreased, and the static yield stress and thixotropy increased as the specimen aged, while the dynamic yield stress remained unchanged. The study found that the Herschel-Bulkley model can accurately describe the PC’s rheological behavior over time. The change in cohesion strength and internal friction angle over time was observed using uniaxial unconfined compression and direct shear tests of fresh PC. A time-dependent MohrCoulomb failure criterion was established. Temperature analysis was used to determine the gel time and explain the evolution of the time-dependent early-age strength …

Advances In Cellulose Nanomaterial-Based Foams For Environmental Applications, Md Musfiqur Rahman

Electronic Theses and Dissertations

The use of metal-oxide nanoparticles adsorbents is limited to fixed-bed columns in industrial-scale water treatment applications. This limitation is commonly attributed to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials, or a lack of adsorption capacity. Foams and aerogels derived from cellulose nanomaterials have unique characteristics, such as high porosity and low density, which enables their use in a variety of environmental applications, including water treatment. However, the overall use of cellulose nanomaterial-based foams in various environmental sectors is limited due to the high cost of production associated with time- and …

Experimental And Computational Platforms For Studying Systems Mechanobiology, Brendyn Miller

All Dissertations

Mechanical stimulation through physical activity has been shown to play an important role in treating and preventing several non-communicable diseases such as hypertension, lower back pain (LBP), type-2 diabetes mellitus, and several cancers. This is accomplished through the regulation of cellular behavior and tissue remodeling within the body at both the micro- and macro-scale levels. The goal of mechanobiology research is to gain in-depth knowledge and understanding of how cells sense physical forces in conjunction with other biochemical cues and translate those factors into important biological functions that either maintain tissue homeostasis or lead to pathological states. Understanding these processes …

Additive Manufacturing For Medical Education, Michael Noon

College of Engineering Summer Undergraduate Research Program

A growing body of evidence is suggesting that anatomical knowledge, the keystone of many medical specialties, is suffering among new graduates. While a host of reasons are provided, one common thread that many point to is the decline of cadaver dissections in the classroom. Many virtual audio-visual tools are used to address this gap, yet evidence has shown their ineffectiveness. Given this gap, the high degree of flexibility found in additive manufacturing (AM), and the many uses AM has already found in the medical field, we propose its use to fill this gap, allowing for students to learn with touch …

A 3d Printed Microneedle System For Transdermal Drug Delivery Of Anticancer Drugs, Md Jasim Uddin, Tanvir Ahmed, Dennis Douroumis

Research Symposium

Background: Transdermal delivery of drugs is an attractive alternative to the conventional route of administration as oral delivery. The hypodermic injections are painful and less patient compliance. Microneedles (MNs) are micron-sized, minimally invasive needles to deliver a wide range of molecules (e.g., small, DNA, vaccines etc.) to the upper portion of the dermis in a sustained and controlled manner, without causing any pain. The introduction of 3D printing technologies in the fabrication of MN will promote one-step manufacturing tools and scale-up for the delivery devices of anticancer drugs.

Methods: The 3D printed MN (3DMN) arrays were fabricated using Stereolithography (SLA), …

Modeling, Control, And Hardware Development Of A Thrust-Vector Coaxial Uav, Andrew North

Doctoral Dissertations and Master's Theses

This thesis introduces a unique thrust vector coaxial unmanned aerial vehicle (UAV) configuration and presents a comprehensive investigation encompassing dynamics modeling, hardware design, and controller development. Using the Newton-Euler method, a dynamic model for the UAV is derived to gain in-depth insights into its fundamental flight characteristics. A simple thrust model is formulated and modified by comparing it with data obtained from vehicle testing. The feasibility of manufacturing such a vehicle is assessed through the development of a hardware prototype. Finally, a linear state feedback controller is designed and evaluated using the non-linear dynamics model. The results demonstrate successful validation …

3d Printed Aircraft, Matthew Nagy, Charles D'Amico, Alexis Salgado Medina

Mechanical Engineering

This project is to design, build, and test a 3D-printable aircraft. The goal is to create a final design that will be able to fly for the longest duration possible, around 20 seconds. To determine the correct preliminary design and manufacturing process for a 3D printed RC aircraft, an analysis of multiple design options and manufacturing materials was performed. This allowed for a variety of choices for aircraft type, airfoil design, structure, among other topics to be narrowed down to the most promising option. It has been found that the aircraft will follow a design similar to industry motor-gliders, with …

Feasibility Of Thermoplastic Extrusion Welding As A Joining Method For Vacuum-Assisted Additively Manufactured Tooling, Chase C. Flaherty

Electronic Theses and Dissertations

In recent years, additive manufacturing (AM) has been successfully utilized for the production of large-scale composite tooling. Within these endeavors, however, limited research has focused on joining methods between printed sections. This work evaluates the feasibility of thermoplastic extrusion welding as a joining method for additively manufactured tooling structures. This joining method was assessed based on industry specifications of conventional thermoset tooling for wind blade manufacturing utilizing the vacuum-assisted resin transfer molding (VARTM) process. The specifications include requirements for the mechanical strength, vacuum integrity, roughness, and hardness of the tool surface. The feasibility of this welded polymer joint was demonstrated …

Pla-S-Tech: Pla Sustainable Technology, Sean Sapper, Ryan Decarlo, Elle Whitney, Samantha Dombrowski, Dalton Prokop, Dominic Zaio, Tyler Stokes, David Deese, Blake Hengel, Yi Guo

Mechanical and Civil Engineering Student Publications

To recycle waste material produced by fused deposition modeling (FDM) 3D printers, a recycler was designed and manufactured to convert plastic scraps into usable filament. The device does so by breaking down plastic material to a uniform size with the shredder, melting and compressing these pieces into a cylindrical strand with the extruder, and wrapping this strand around a filament spool with the spooler. As the device is mostly made from commercially-available components, it is easily maintainable and user-serviceable, while also costing less than similar devices on the market.

Gestural Design - Hand Tracking For Digital Drawing, Jordan A. Kanter, Kamil Quinteros

Architecture and Planning Journal (APJ)

Computational design is increasingly interested in the active feedback between the user/designer and the digital space. Often, our initial instinct as designers comes from a gesture, a movement of the hands that gets translated into sketches and 3D models via the tools available to us. While the physical realm allows for muscle memory, tactile feedback, and creative output via movement, digital design often negates the body of the designer as it sequesters us into a screen-mouse-hand relationship. Moreover, current CAD software tools often reinforce this standardization, further limiting the potential of physical bodily gestures as a vehicle for architectural form-making. …

On The Permittivity Of Xt-Cf20, Aaron Harmon, Wei Zhang, Victor Khilkevich

Electrical and Computer Engineering Faculty Research & Creative Works

In This Work, the Permittivity of a 3D-Printed Carbon Fiber-Loaded Anisotropic Material, XT-CF20, is Examined Further. the Microstructure of XT-CF20 is First Examined Via Optical Imaging and is Shown to Be Composed of Inclusions that Are Aligned with the Print Direction of the Sample. the Permittivity Tensor for the Aligned Microstructure is Then Measured using a Capacitive Measurement Technique and Simulations Are Provided to Demonstrate the Validity of This Measurement Method. the Simulated Permittivity Values for XT-CF20 Samples with Varying Infill Structures Are Then Presented and Compared to the Measured Permittivity Values of Said Samples. an Error of Less Than …

An Experimental Study Of The Impinging And Freezing Dynamics Of A Colloidal Droplet On Solid Surfaces, Andro Fayek Abdelmalek

Dissertations and Theses

In modern manufacturing, the production of complex components with intricate geometries and varying material compositions has become essential. To meet these demands, additive manufacturing (AM) has gained prominence. Various 3D printing technologies, such as stereolithography (SLA), selective laser sintering (SLS), and plastic extrusion, have been developed to produce finished components. However, each technology has its limitations, including restricted printing resolution or limited material selection. A novel idea in additive manufacturing involves the utilization of inkjet printing nozzles with colloidal fluid and implementing the freeze-dry method. This innovative technique entails depositing colloidal droplets onto a freezing substrate using an inkjet head. …

Wetting Transition Of Texturized Surfaces, Jenna Stephens

Williams Honors College, Honors Research Projects

Building on previous research, this project aims to continue the investigation of the wettability of various liquids on a uniform, texturized surface. Different surface energies can impact the wettability of a surface. The surface can be hydrophilic, hydrophobic, or in between. The goal of this project is to research how features of texturized surfaces affect the wetting transition of water, oil, and a mixture of both. Additionally, this project aims to improve the quality of the 3D printed surfaces. The surfaces that will be studied are constructed using UV cured resin 3D printing and are made up of an array …

Part Design Geometry-Driven Toolpath Optimization For Additive Manufacturing Energy Sustainability Improvement, David Kolawole Somade

Graduate Research Theses & Dissertations

One of the most promising new manufacturing technologies in the past three decades isadditive manufacturing (AM), also commonly known as three-dimensional (3D) printing or rapid prototyping. The energy consumption problem in AM can be significant when it is adopted at the industrial scale or used under resource-restricted conditions. The energy consumption of an AM process is influenced by several factors including bed heating, filament extrusion, material infill, component cooling, etc. All these factors are further determined by the equipment and the toolpath for a specific printing task. Build orientation and tool-path direction are frequently used to optimize part and process …

Thermoplastics 3d Printing Using Fused Deposition Modeling On Fabrics, Maxwell M. Blais

Electronic Theses and Dissertations

The creation of objects with integrated flexibility is desired and this can be achieved by additive manufacturing on fabric. We propose to use a textile fabric as a flexible joint and create to create an entire object with smaller parts called segments. Such a novel technique will bring integrated flexibility and folded assemblies using extrusion based additive manufacturing machines. The proposed process allows segments to be created flat one at a time on a continuous fabric, which will be suitable for flat to folded assemblies and eliminate size limitations of the 3D printer. Techniques considering object segmentation were used to …