Engineering Commons^™

Development Of A 3d Printed Conductive Biopolymer For Cardiac Tissue Engineering, Britanny Lizeth Stark

Open Access Theses & Dissertations

Cardiovascular disease (CVD) is the leading cause of death in the US, with approximately 859,000 deaths each year. The major contributor to CVD is Acute Myocardial Infarction (AMI), which causes the death of approximately 25% of the cardiomyocytes present in the left ventricle of the heart. After AMI, the adult human heart has a very limited regenerative capacity. Moreover, the electrical propagation of the myocardium is severely disrupted, making the heart more susceptible to failure and patient death. However, current pharmacological treatments do not address the loss of cardiomyocytes and the disruption of electrical propagation in the heart. Tissue engineering …

Additive Manufacturing Of Composites For Sensing And Harsh Environments Application, Md Sahid Hassan

Open Access Theses & Dissertations

Composite materials are made by combining two or more materials, such as fibers and resins to create a material system that has improved mechanical and physical properties compared to its individual components. The use of 3D printing technology in composite manufacturing allows for the creation of complex and custom shapes with precise control over the placement of the materials. This makes it possible to create composite parts with enhanced performance characteristics and reduced weight. The work presented in this dissertation lies in the design and development of highly flexible impact propagation sensor through material extrusion 3D printing technique. By using …

Analyzing The Effects Of Ultrafast Laser Processing On Mechanical Properties Of 3d-Printed Pla Parts, Darshan Pramodbhai Yadav

Theses and Dissertations

Recent advances in additive manufacturing technologies have already led to wide-scale adoption of 3D-printed parts in various industries. The expansion in choice of materials that can be processed, particularly using Fused Deposition Modeling (FDM), and the steady advancements in dimensional accuracy control have extended the range of applications far beyond rapid prototyping. However, additive manufacturing still has considerable limitations compared to traditional and subtractive manufacturing processes. This work addresses limitations associated with the as-deposited surface roughness of 3D-printed parts. The effects of roughness-induced stress concentrations were studied on ultimate tensile strength and fatigue life. The samples were manufactured using a …

Advancing Additive Manufacturing For Biomedical Applications: Antimicrobial And X-Ray Absorptive Composite Filaments For Fused Filament Fabrication, John M. Arnold Jr

University of New Orleans Theses and Dissertations

The objective of this research was to investigate the use of nano- and microparticle amendments for the creation of Poly-lactic Acid composite materials for use in biomedical applications using the Fused Filament Fabrication process of Additive Manufacturing. Composites were created with the goal of imparting the useful properties of antimicrobial activity and x-ray absorption to the material. In addition to testing the efficacy of the particle amendments in achieving the desired properties, the thermal and mechanical properties of the composite materials were tested to ensure that the composites would be compatible with the Fused Filament Fabrication process and would produce …

Damage Detection With An Integrated Smart Composite Using A Magnetostriction-Based Nondestructive Evaluation Method: Integrating Machine Learning For Prediction, Christopher Nelon

All Dissertations

The development of composite materials for structural components necessitates methods for evaluating and characterizing their damage states after encountering loading conditions. Laminates fabricated from carbon fiber reinforced polymers (CFRPs) are lightweight alternatives to metallic plates; thus, their usage has increased in performance industries such as aerospace and automotive. Additive manufacturing (AM) has experienced a similar growth as composite material inclusion because of its advantages over traditional manufacturing methods. Fabrication with composite laminates and additive manufacturing, specifically fused filament fabrication (fused deposition modeling), requires material to be placed layer-by-layer. If adjacent plies/layers lose adhesion during fabrication or operational usage, the strength …

Evaluation Of Biomass As Bio-Additive In 3d Printing, Shuyang Zhang

Doctoral Dissertations

The petrol-based polymer has been widely applied in current daily life. The end-of-life of polymeric products has drawn environmental concerns. One of the solutions to such issues is to use bio-renewable materials to replace or reduce the use of petrol-based materials. Lignocellulosic materials are one of the potential candidates. Along with the features of 3D printing and the unique properties of biomass, 3D-printed biomass-based materials could be promising in preparing sustainable alternatives.

In this dissertation, lignin and other biomass were applied to various 3D printing techniques for sustainable composites. Stereolithography (SLA) was first used, and the kraft softwood lignin was …

Northrop Grumman Collaboration Project, Nikkia Psomas-Sheridan, Santiago Robles, Ben Elkayam, Benjamin Ulfhake

Mechanical Engineering

The Northrop Grumman Collaboration Project (NGCP) is a collaborative club project sponsored by Northrop Grumman for the students of Cal Poly San Luis Obispo (CPSLO) and Cal Poly Pomona (CPP) to create a fleet of vehicles to aid in the simulated rescue of stranded hiker. The CPSLO club is responsible for delivering an autonomous flight vehicle that can suppress a fire and retrieve a payload. Mechanical Design Team of the CPSLO team was responsible for the design of the frame, electronics housing, and payload and fire suppression systems.

3d Printing Of Earthen Materials: Toward The Carbon-Zero Construction, Shiva Bhusal

Civil Engineering ETDs

In recent years, digital manufacturing techniques in the architecture and construction industry have rapidly gained attention, especially with 3D printing, also called additive manufacturing. The use of cement has been common in modern construction and is now being explored for 3D printing. However, due to cement's contribution to approximately 7 percent of global carbon emissions and its high cost, research on sustainable and greener materials has gained attention. Previous studies on alternative construction have examined the mechanical and rheological properties of soil mixes, but not much attention has been given to printability evaluation, shrinkage, and cracking, which can affect the …

Low-Cost Microstereolithography 3d Printing With Microfluidic Microsampling Applications, Lauren Twombly

Chemistry & Biochemistry Undergraduate Honors Theses

The growing field of stereolithography 3D printing has welcomed a new age ofmicrofluidic device fabrication techniques. When compared to previous planar fabrication techniques such as soft-lithography, stereolithography 3D printing offers highly automated procedures, reduced fabrication times, and greater complexity of device features. To date, the greatest tradeoff for 3D printing in microfluidic device fabrication is poorer resolution when compared to soft-lithography which can produce feature sizes on the nanometer scale. The poorer resolution of 3D printing limits the feasible size of features. While highly sophisticated 3D printers are capable of achieving sub 10 μm resolution, these instruments are incredibly expensive …

Engineered Material Systems For Mimicking Tissue And Disease, Margrethe Ruding

McKelvey School of Engineering Theses & Dissertations

This thesis comprises two studies involving design and application of soft material systems. The goal of the first study was to design, fabricate, and characterize hydrogel lattice structures with consistent, controllable, anisotropic mechanical properties. Lattices, based on four types of unit cells (cubic, diamond, vintile, and Weaire-Phelan), were printed using stereolithography (SLA) of polyethylene glycol diacrylate (PEGDA). In order to create structural anisotropy in the lattices, unit cell design files were scaled in one direction by a factor of two in each layer and then printed. The mechanical properties of the scaled lattices were measured in shear and compression and …

Automated Sensing Methods In Soft Stretchable Sensors For Soft Robotic Gripper, Prosenjit Kumar Ghosh

Electrical Engineering Theses

A soft robot is made from deformable and flexible materials such as silicone, rubber, polymers, etc. Soft robotics is a rapidly evolving field where the human-robot-interaction and bio-inspired design align. The physical characteristics such as highly deformable material and dexterity make soft robots widely applicable. A soft robotic gripper is a robotic hand that acts like a human hand and grasps any object. The most common applications of soft robotics grippers are gripping and locomotion in sensitive applications where high dynamic and sensitivity are essential. Nowadays, soft robotics grippers are used without any sensing method and feedback as it is …

Northrop Grumman Collaboration Project, Nikkia Rae Psomas-Sheridan, Santiago Robles, Ben Elkayam, Benjamin Ulfhake

Mechanical Engineering

The Northrop Grumman Collaboration Project (NGCP) is a collaborative club project sponsored by Northrop Grumman for the students of Cal Poly San Luis Obispo (CPSLO) and Cal Poly Pomona (CPP) to create a fleet of vehicles to aid in the simulated rescue of stranded hiker. The CPSLO club is responsible for delivering an autonomous flight vehicle that can suppress a fire and retrieve a payload. Mechanical Design Team of the CPSLO team was responsible for the design of the frame, electronics housing, and payload and fire suppression systems.

Longitudinal Oxygen Imaging In 3d (Bio)Printed Models, Ryan Curtis O'Connell

Graduate Theses, Dissertations, and Problem Reports

Electron paramagnetic resonance (EPR), and its molecular imaging modality, is a powerful tool to noninvasively map various biological and chemical markers within objects of interest. Reliable data acquisition is a major impeding factor for longitudinal hands-off measurements. Measurements are especially challenging in biomedical applications, as live objects are not static. Frequent changes occur that require constant fine recalibration of the EPR detection system, called the resonator. To enable longitudinal imaging, a technology permitting automatic digital control of resonator coupling, tuning, and EPR data acquisition was developed. Automation was achieved through the utilization of a microcontroller and digital peripheral components such …

Nasa Student Launch Payload Deployment, Kallysta Ray

All Undergraduate Projects

For the NASA Student Launch Competition, a deployment system was created to deploy the payload of the rocket. To accomplish this the deployment system was designed, analyzed, manufactured, and tested to meet the requirements from the NASA Competition. The requirements included deployment of the payload as well as staying within 4 pounds. The project requirements were researched and each of the proposed components had analyses completed. The analyses included weight calculations, stress, and deflection analyses using statics, mechanics of materials, and dynamics. There were many discussions throughout the project between the teammates to ensure all components of the payload and …

Radio-Controlled Baja Car, Jaxx Brown

All Undergraduate Projects

The Central Washington University RC Baja competition tests students’ skills in engineering in a matter of ability to design, construct and test an RC car. The objective of this senior project is to manufacture efficient suspension and steering systems for an RC vehicle and compete at the end of the school year against other students’ vehicles. Two races will be conducted during the competition, the RC vehicle will compete in a slalom-and-sprint and a Baja. Using more than one manufacturing method and material was expected of students to create the steering and suspension systems. Through CAD software and 3D printers …

Anisotropic Material Behavior Of 3d Printed Fiber Composites, Jordan Garcia

Theses and Dissertations--Mechanical Engineering

Literature has shown that 3D printed composites may have highly anisotropic mechanical properties due to variation in microstructure as a result of filament deposition process. Laminate composite theory, which is already used for composite products, has been proposed as an effective method for quantifying these mechanical characteristics. Starting with the analysis of comparing the printing orientation of premanufactured carbon fiber reinforced filament, the mechanical properties of 3D printed objects were examined. The mechanical properties changed not only as a result of machine choice, but how the sample is oriented along the printing bed. The analysis continued with looking at the …

Fabrication Of Solar Absorber Tube With Internal Fin Structure With In718 And Effect Of Boron With In718 For Solar Absorber Tube Using Selective Laser Melting 3d Printing Technology, Naznin Nuria Afrin

Theses and Dissertations

This research aimed to fabricate Solar Absorber Tubes for Solar-Thermal Power Plant with internal fin structures using Selective Laser Melting (SLM) technology. In this study, we investigated the effect of B with IN718 in 3D printing using SLM for solar absorber tubes. The objective was to study the material-process-properties relationship with goal to identify and validate the optimal parameters for the SLM process. Material selected for this study was IN718 with 0.5% and 1% B particle mixed using a V-shape mixing machine. The flowability test was conducted using the Angle of Repose (AOR) method. 3D printed samples …

Experimental Tests And Numerical Study Of Trajectories Of Different Types Of Dropped Objects, Yi Li

University of New Orleans Theses and Dissertations

In marine and offshore engineering, dropped objects, such as drill pipes, anchor chains, containers and some small parts, can accidentally fall into the water from ships or offshore platforms, causing casualties on deck or damage to underwater equipment. Damaged equipment can further harm the environment, such as oil spills from damaged wellheads. Therefore, for safe engineering and environmental protection reasons, we need to develop methods and tools that can predict the trajectory of dropped objects.

In this dissertation, we first study containers dropped from ships. More and more containers are falling into the sea due to bad weather. Containers lost …

Design, Evaluation, And Control Of Nexus: A Multiscale Additive Manufacturing Platform With Integrated 3d Printing And Robotic Assembly., Danming Wei

Electronic Theses and Dissertations

Additive manufacturing (AM) technology is an emerging approach to creating three-dimensional (3D) objects and has seen numerous applications in medical implants, transportation, aerospace, energy, consumer products, etc. Compared with manufacturing by forming and machining, additive manufacturing techniques provide more rapid, economical, efficient, reliable, and complex manufacturing processes. However, additive manufacturing also has limitations on print strength and dimensional tolerance, while traditional additive manufacturing hardware platforms for 3D printing have limited flexibility. In particular, part geometry and materials are limited to most 3D printing hardware. In addition, for multiscale and complex products, samples must be printed, fabricated, and transferred among different …

Conducting Polypyrrole Hydrogel Biomaterials For Drug Delivery And Cartilage Tissue Regeneration, Iryna Liubchak

Electronic Thesis and Dissertation Repository

Articular cartilage tissue has limited capacity for self-regeneration leading to challenges in the treatment of joint injuries and diseases such as osteoarthritis. The tissue engineering approach combines biomaterials, cells and bioactive molecules to provide a long-term and stable cartilage repair. In the following work, electroactive polymer polypyrrole~(PPy) was incorporated into the synthetic hydrogel to enhance the mechanical properties of the material for cartilage applications. PPy was loaded with drug compound and the \emph{on demand} drug release was demonstrated. The composite PPy hydrogel was 3D printed using stereolithography to create a porous tissue engineering scaffold. Biocompatibility and cell adhesion to the …

Developing Ultra-High Resolution 3d Printing For Microfluidics, Kent Richard Hooper

Theses and Dissertations

Building upon previous research on Digital Light Projection (DLP) 3D printing for microfluidics, in this thesis I performed the detailed design and fabrication of a novel DLP 3D printer to increase resolution and device footprint flexibility. This new printer has a pixel resolution twice that of our group’s previous printers (3.8 μm vs 7.6 μm). I demonstrated a new state of the art for minimum channel width, reducing the minimum width to 15 μm wide (and 30 μm tall). This is an improvement over the previous smallest width of 20 μm. This printer also has the capacity to perform multiple …

Additive Manufacturing Of Sub-Micron Features And Mechanical Linkages, David K. Limberg

Doctoral Dissertations

In recent years material constraints have become the limiting factor in several fields, including batteries, robotics, and medicine, and these needs have prompted the development of materials with programmable properties. To this end, much effort has been dedicated to designing metamaterials that have unprecedented optical, mechanical, and thermal properties, along with systems for additive manufacturing to build their complex structures with high precision and throughput. The field of additive manufacturing has proved to be a platform for innovation across many industries yet is still limited with regards to feature sizes, print rates, and diversity of materials. Mechanical devices like linkages …

Bongoties Tying Machine Design, Zachary Stednitz, Tori Bornino, Jackson Mclaughlin, Shea Charkowsky

Mechanical Engineering

BongoTies are a reusable tool for cable management or general fastening, consisting of a strong rubber band attached to a bamboo pin. BongoTies is a company founded by our sponsor Tim Petros that sells its product on a variety of popular shopping sites, such as Amazon and eBay. Currently, the assembly process is to hand-tie the rubber band to the pin for every BongoTie. This is too slow to keep up with demand, requires a skilled worker with good dexterity, and can cause pain or injury if the rubber band snaps back onto the worker’s fingers. In this senior project …

A Novel Electroconductive Nanofibrous Scaffold For Bone Regeneration, Mitchell Kenter

Medical Engineering Theses

The goal of this study was to develop a biodegradable and conductive scaffold to mimic the piezoelectric properties of bone and the architecture of the extracellular matrix. Poly(3,4- ethylenedioxythiophene) (PEDOT) is a conductive polymer of great interest in tissue engineering due to excellent electrical stability and biocompatibility. To enhance its conductivity, dopants such as dimethyl sulfoxide (DMSO) can be added. Engineered graphene oxide (GO) can also be introduced as oxidant to enhance conductivity and mechanical properties. PEDOT nanocomposites were synthesized by oxidative polymerization of 3, 4-Etylenedioxythiophene monomer (EDOT) in the presence of GO, DMSO, ferric chloride and various solvents. The …

Nondestructive Evaluation Of 3d Printed, Extruded, And Natural Polymer Structures Using Terahertz Spectroscopy And Imaging, Alexander T. Clark

Dissertations

Terahertz (THz) spectroscopy and imaging are considered for the nondestructive evaluation (NDE) of various three-dimensional (3D) printed, extruded, and natural polymer structures. THz radiation is the prime candidate for many NDE challenges due to the added benefits of safety, increased contrast and depth resolution, and optical characteristic visualization when compared to other techniques. THz imaging, using a wide bandwidth pulse-based system, can evaluate the external and internal structure of most nonconductive and nonpolar materials without any permanent effects. NDE images can be created based on THz pulse attributes or a material’s spectroscopic characteristics such as refractive index, attenuation coefficient, or …

Autonomous Material Refill For Swarm 3d Printing, William C. Jones

Mechanical Engineering Undergraduate Honors Theses

3D printing currently offers robust and cheap rapid prototyping solutions. While standard 3D printing remains at the periphery of mass production, the technology serves as a starting point for the development of swarm manufacturing. Since swarm manufacturing is predicated upon autonomy, swarm technology companies such as AMBOTS are seeking to minimize human involvement in the swarm’s functions. At present, the 3D printing swarm consists of the printers, a transporter which can take them between job sites, and the floor tiles which provide power and support the build surfaces. To add to this ecosystem, this project is focused on the design …

A New Approach For 3d Printed Microfluidic Device Design Based On Pre-Defined Components, Cassandra Ester Slaugh

Theses and Dissertations

3D printing for microfluidic device fabrication has received considerable interest in recent years, in part driven by the potential to dramatically speed up device development by reducing device fabrication time to the minutes timescale. Moreover, in contrast to traditional cleanroom-based fabrication processes that require manual production and stacking of a limited number of layers, 3D printing allows full use of the 3D fabrication volume to lay out microfluidic elements with complex yet compact 3D geometries. The Nordin group has successfully developed multiple generations of high resolution printers and materials for microfluidic devices that achieve this vision. However, because of the …

Rational Design Of Flexible And Stretchable Electronics Based On 3d Printing, Yuanhang Yang

Theses and Dissertations

Flexible and stretchable electronics have been considered as the key component for the next generation of flexible devices. There are many approaches to prepare the devices, such as dip coating, spin coating, Mayer bar coating, filtration and transfer, and printing, etc. The effectiveness of these methods has been proven, but some drawbacks cannot be ignored, such as lacking pattern control, labor consuming, requiring complex pretreatment, wasting conductive materials, etc.

In this investigation, we propose to adopt 3D printing technology to design flexible and stretchable electronics. The objective is to rationally design flexible and stretchable sensors, simplify the preparation process, form …

Recycled Printer Filament, Charlotte Hyland, Troy D. Molinar

Williams Honors College, Honors Research Projects

The purpose of this research is to examine the effects of recycling PLA filament for 3D printing on its material properties. After examining these effects, PLA and carbon fiber additives were mixed with recycled PLA pellets in different ratios to attempt to regain material properties lost in the recycling process. To complete these findings, an experiment was design and executed.

The research found that tensile strength during multiple iterations of recycling remained mostly unaffected, however, the strain degraded exponentially. In the PLA additive study, high ratios of PLA additive were able to increase the strength and strain properties of the …

The Study Of 3d Micro-Fluid Printing In Aqueous Two-Phase System, Mian Huang

Dissertations and Theses

Aqueous two-phase system (ATPS) is a technology that allows phase separation in an aqueous environment. This technology can be used for the separation, extraction and purification of a variety of biomolecules and thus gained great attention in industry and academia. This thesis is a combination of ATPS, 3D printing, and microfluidics technologies and realizes the printing of biocompatible aqueous structures in another aqueous matrix. The objectives of this thesis include 1) customizing a regular thermal extrusion 3D printer for printing 3D aqueous structures, 2) printing 3D aqueous structure in an aqueous matrix, and 3) studying the stability of the printed …