Engineering Commons^™

Viability Of Additive Manufacturing For Production And Tooling Applications: A Development Of The Business Case, Christopher Charles Griffin

Masters Theses

As marketplace competition drives industrial innovation to increase product value and decrease production costs, emerging technologies foster a new era through Industry 4.0. One aspect of the movement, additive manufacturing, or 3D [three-dimensional] printing, contains potential to revolutionize traditional manufacturing techniques and approach to design. However, uncertainties within the processes and high investment costs deter corporations from implementing and developing the technology. While several industries are benefitting from additive manufacturing’s current state, as the technology continues to progress, more companies will need to evaluate it for industrial viability and adoption. As such, there exists a need for a framework to …

Fluid Flow Characterization And In Silico Validation In A Rapid Prototyped Abdominal Aortic Aneurysm Model, Dean Thomas Wampler

Master's Theses

Aortic aneurysms are the 14^th leading cause of death in the United States. Annually, abdominal aortic aneurysm (AAA) ruptures are responsible for 4500 deaths. There are another 45,000 repair procedures performed to prevent rupture, and of these approximately 1400 lead to deaths. With proper detection, the aneurysm may be treated using endovascular aneurysm repair (EVAR). Understanding how the flow of the blood within the artery is affected by the aneurysm is important in determining the growth of the aneurysm, as well as how to properly treat the aneurysm. The goal of this project was to develop a physical construct …

On Demand 3d Printed Hybrid Scaffolds For Tissue Engineering Applications, Ivan D. Hernandez

Open Access Theses & Dissertations

A composite 3D printed polymer scaffold with inbuilt porosity and filled with a hydrogel can provide an ideal support system for cell growth, proliferation, and vascularization. Therefore, a hybrid system of 3D printed polycaprolactone (PCL) scaffold and a hydroxyapatite-based hydrogel was developed for application in the reconstruction of bone defects, which are inherently difficult to repair without any guided therapies. In the present study, a 3D printed gyroid structure of PCL allowed the loading of a higher amount of hydrogel as compared to conventionally used 3D printed mesh structure of the same volume and strut thickness. The hydrogel was composed …

Design And Implementation Of An Air Multiplier Fan For Pc, George Demian

Williams Honors College, Honors Research Projects

Mechanical engineering student (B.S.) senior design project. Conception, design (SolidWorks), 3D printing & processing, testing of a scaled down air multiplier "bladeless" fan within a computer chassis as a cooling solution.

Development Of An Electrospun And 3d Printed Cellular Delivery Device For Dermal Wound Healing, Ryan M. Clohessy

Theses and Dissertations

The goal of this research was to develop a system of individualized medicine that could be applied to dermal wounds serving as a wound dressing and synthetic extracellular matrix while delivering stem cells to the wound bed. First, fabrication parameters for electrospinning polymer fibers were determined. This involved evaluating fiber morphology with respect to polymer selection and solution concentration. Next, construct fabrication was examined to produce an integrated void space, or cargo area, suitable to maintain stem cells. In vitro studies to ensure stem cell viability and phenotype were conducted, and results supported the notion that cells could be administered …

Bio Inspired Lightweight Composite Material Design For 3d Printing, Kaushik Thiyagarajan

Electronic Theses and Dissertations

Lightweight material design is an indispensable subject in product design. The lightweight material design has high strength to weight ratio which becomes a huge attraction and an area of exploration for the researchers as its application is wide and increasing even in every day-to-day product. Lightweight composite material design is achieved by selection of the cellular structure and its optimization. Cellular structure is used as it has wide multifunctional properties in addition to the lightweight characteristics. Applications of light weight cellular structures are wide and is witnessed in all industries from aerospace to automotive, construction to product design. In this …

Design And Realization Of A Nonlinear Vibration Energy Harvester For Cost Effective Additive Manufacturing, Rodrigo Barriuso De Juan

Masters Theses

Environmental energy harvesting has always been an attractive solution to the search for sustainable energy sources. Combined with the miniaturization and power consumption reduction of sensors and portable electronic devices, the possibility of powering using environmental energy, like vibration energy, instead of conventional batteries increases exponentially. Vibrational energy harvesting can be achieved using devices based on different physical phenomena. Electromagnetic based devices seem to be among the most effective when considering the power output levels within low frequency applications. However, these devices have always had inherent challenges including size and manufacturing cost reduction as well as limitations on the range …

Size Scaling Of Strength And Toughness For 3d Printed Polymer Specimens, Darren Thomas Bell

Open Access Theses

To find material systems that offer low density and high strength, stiffness or toughness, hierarchically designed material systems have provided a promising research area. This thesis lays the groundwork for designing efficient micro-architectured material systems by characterizing size effects for 3d printed polymer parts. Two methods were used to analyze data from 3-point bend tests for specimens of varying size: the load-separation method was used for finding the point of crack growth initiation and Bazant’s method was used to find shape independent strength at failure. The strength values were used as inputs for finding size independent material constants within a …

A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox

Electronic Theses and Dissertations

We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external …

Additive Manufacturing Of Carbon Fiber-Reinforced Thermoplastic Composites, Nicholas M. Denardo

Open Access Theses

Additive manufacturing, or 3D printing, encompasses manufacturing processes that construct a geometry by depositing or solidifying material only where it is needed in the absence of a mold. The ability to manufacture complex geometries on demand directly from a digital file, as well as the decreasing equipment costs due to increased competition in the market, have resulted in the AM industry experiencing rapid growth in the past decade. Many companies have emerged with novel technologies well suited to improve products and/or save costs in various industries.

Until recently, the applications of polymer additive manufacturing have been mainly limited to prototyping. …

Fluid Flow Characterization And In Silico Validation In A Rapid Prototyped Aortic Arch Model, Alexandra Mariel Knauer

Master's Theses

Transcatheter aortic heart valve replacement (TAVR) is a procedure to replace a failing aortic valve and is becoming the new standard of care for patients that are not candidates for open-heart surgery [2]. However, this minimally invasive technique has shown to cause ischemic brain lesions, or “silent infarcts”, in 90% of TAVR patients, which can increase the patient’s risk for stroke by two to four times in future years [3]. Claret Medical Inc., a medical device company, has developed a cerebral protection system that filters and captures embolic debris released during endovascular procedures, such as TAVR. This thesis utilized CT …

Improving The Mechanical Performance Of 3d Printed Parts Using Fused Filament Fabrication, Inderpreet Binning

Industrial and Manufacturing Engineering

The 3D printing industry has seen rapid growth in the last 10 years and has been called the next industrial revolution. There are several different processes used in 3D printing, but the most popular process is called Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM). This is the process where (most commonly) plastic filament enters a nozzle, is heated to a semi-liquid state, and then deposited into a pattern to create a print. One major drawback to this process is that the prints are anisotropic. This means that the strength of the print varies with the orientation that it …

A Concrete Water Pasteurization Device For Third World Countries, Andrea R. Murchie

Senior Honors Projects, 2010-2019

In the rural areas of South Africa, as well as many other developing countries, people cook food and sterilize their water by heating over open fires. Many times the fires are inside of homes, which more often than not are very small. Children will often be the ones to tend to the fire, out of necessity while parents and other family members are tending to other work and needs.

The purpose of my Senior Honors Project was to design a concrete vessel that can hold water and heat the water to pasteurization (149°F) when exposed to sunlight for an extended …

Stiffness Reduction Strategies For Additively Manufactured Compliant Mechanisms, Ezekiel G. Merriam

Theses and Dissertations

This work develops and examines design strategies for reducing the stiffness of 3D-printed compliant mechanisms. The three aspects of a flexure that determine its stiffness are well known: material, boundary conditions, and geometry. In a highly constrained design space however, flexure stiffness may remain unacceptably high even while arriving at the limits of design constraints. In this work, changes to geometry and boundary conditions are examined that lead to drastically reduced stiffness behavior without changing flexure thickness, width, or length. Changes to geometry can result in very complex mechanisms. However, 3D printing enables almost arbitrarily complex geometries. This dissertation presents …

3d Printed Bone Supplement Materials, Azem Khalifa Yahamed

Dissertations

Three-dimensional (3D) printing is an advanced rapid technology that can be used to make human bone substitutes with exact shape and designed structures, based on models created from actual individual bone medical Digital Imaging and Communications in Medicine (DICOM) images. Biocompatible polymers have been selected for 3D printing of human bone structures. The thermoplastics were 3D printed with Fused Deposition Modeling (FDM) are Acrylate Butadiene Styrene (ABS), Polylactic Acid (PLA) and ULTEM 9085 (a polyetherimide). The polyamide PA 2200 was 3D printed using Selective Laser Sintering (SLS). Digital ABS (a crosslinked acrylic polymer) was 3D printed using PolyJet Technology. These …

Additive Manufacturing Process Parameter Effects On The Mechanical Properties Of Fused Filament Fabrication Nylon, Eric S. Holm

Theses and Dissertations

The purpose of this research was to determine how varying Fused Filament Fabrication (FFF) process parameters affect the mechanical properties of PA6 nylon dog-bone specimens produced on the Mark One 3D Printer. A design of experiment (DOE) was conducted using the factors of layer height and raster angle orientation. The mechanical properties measured in the experiment were tensile modulus, yield stress, percent strain at yield, ultimate tensile strength and percent strain at break. An analysis of variance (ANOVA) was performed to identify which factors were statistically significant in influencing mechanical properties. Results of the ANOVA showed that layer height was …

Asme Mini-Baja Rc Car (Steering And Suspension Systems), Michael E. Cox

All Undergraduate Projects

The issue that this project is concerned with is how to design and build a drivetrain, steering and suspension systems for an RC car. The systems must be simple and functional. Furthermore, these systems will be designed to fit on a small chassis and not interfere with each other. They also need to be strong and durable enough to propel the car forward and maneuver through various obstacles and be built in a way that is easy to take apart and repair quickly. These design problems were approached using basic mechanical design concepts such as gear kinematics, spur and bevel …

Digital Processes And Characterization For Fabricating 3d Rf Devices, Harvey Hing Tsang

Open Access Theses & Dissertations

In this work, co-planar waveguides (CPW) are fabricated and characterized with low temperature 3D printed materials for flexible electronic applications. Laser processing is introduced to reduce heating and cooling times for curing and subtractive manufacturing. CPWs are optimized by varying printing resolution, adjusting curing conditions and shaping conductor profile with a pico-laser. By using acrylonitrile butadiene styrene (ABS) as substrate material and Dupont CB028 as conductive material, a high S21 and low S11 CPW is fabricated. Optimized direct write methods are dispensed onto 3D complex structures to move away from 2.5D style printing and move into true 3D printed antenna …

Design Of Elastic Metamaterials, Yu-Chi Su

Open Access Dissertations

This study focused on the design and fabrication of a double negativity and three broadband single negativity elastic metamaterials using a 3D printer. We investigated dispersion curves and dynamic material properties of the metamaterials. Negative phase velocity in the double negativity metamaterial was also demonstrated.

For metamaterials with single negativity, three types of broadband metamaterials were designed from parametric studies. A comparison showed that using frame bending/stretching mode is more effective than applying beam bending mode to broaden bandgap. Furthermore, it is found that adding internal resonant components could enlarge the bandgap. The single negativity metamaterials were validated by numerical …

A Study On 2.45 Ghz Bandpass Filters Fabricated With Additive Manufacturing, Nicholas Christian Arnal

USF Tampa Graduate Theses and Dissertations

Square open loop resonator (SOLR) bandpass filters fabricated with additive manufacturing techniques are presented and studied. One filter contains novel 3D capacitive plates used to enhance resonator coupling. The filters are centered at 2.45 GHz and loaded with capacitors for miniaturization as low as 21% that of a conventional SOLR bandpass filter. The pass-band insertion loss of the filters ranges from 3.8 dB to 5.5 dB and the 3 dB bandwidth ranges from 180 MHz to 250 MHz. Also, degradation in the effective conductivity of printed ink as a function of substrate roughness is analyzed. Finally, a study of dielectric …

Use Of Direct Metal Laser Sintering For Tooling In High Volume Production, Joel W. Hendrickson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Metal 3D printing has caught the attention of many large industries. There have been stories of great success using metal 3D printing. Some of the largest industries to successfully use metal 3D printing are aerospace and medical. These industries have succeeded with metal 3D printing because of their need for light and complex parts. These success stories lead other industries to investigate how metal 3D printing or Direct Metal Laser Sintering (DMLS) can help them. Industries that are involved in high volume production ask how they can take advantage of the complexity and customization that is available with 3D printing. …

A Market-Based Approach To 3d Printing For Economic Development In Ghana, Wade Aitken-Palmer

Dissertations, Master's Theses and Master's Reports - Open

The purpose of this report is to create the foundation for further study of a market-based approach to 3D printing as an instrument for economic development in Ghana. The delivery of improved products and services to the most underserved markets is needed to spur economic activity and improve standards of living. The relationship between economic development and the advancement of technology is considered within the context of Ghana. An opportunity for market entry exists within both the bottom of the economic pyramid and the mid-segment market. 3D printing (additive manufacturing) has proven to be a disruptive technology that has demonstrated …

Healing Of Bone Defects In A Rodent Calvarial Defect Model Using Strong Porous Bioactive Glass (13-93) Scaffolds, Yinan Lin

Masters Theses

"The main objective of this project was to evaluate the capacity of strong porous silicate (13-93) bioactive glass scaffolds prepared by a robocasting technique to regenerate bone and stimulate angiogenesis in a rat calvarial defect model. The scaffolds were created with the same grid-like microstructure but in a variety of formulations: (i) as-fabricated, (ii) pretreated in an aqueous phosphate solution to convert the glass surface to hydroxyapatite, (iii) loaded with bone morphogenetic protein-2 (BMP2) (1 µg per scaffold), and (iv) doped with copper (0.4-2.0 wt. % CuO). When compared to the as-fabricated scaffolds, the pretreated scaffolds enhanced bone regeneration at …

Farmbot, James Cruz, Scott Herrington, Bryan Rodriguez

Mechanical Engineering

The purpose of this project was to develop the hardware for the current Farmbot to perform its primary functions, and to create a template for a system that would be adaptable for future users and developers. The scope of the project included creating a universal tool mount, a seeding system, and a watering and nutrient mixing system. This project was brought to the students by sponsor Rory Aronson, the creator of Farmbot. The Cal Poly Farmbot team was able to go through an extensive brainstorming and iterative process for each part, where testing was able to be incorporated immediately due …

Nanotechnology And Additive Manufacturing Platforms For Clinical Medicine: An Investigation Of 3d Printing Bioactive Constructs And Halloysite Nanotubes For Drug Delivery And Biomaterials, Jeffery A. Weisman

Doctoral Dissertations

Personalized medicine requires the development of new technologies for controlled or targeted drug delivery. Three-dimensional (3D) printing and additive manufacturing techniques can be used to generate customized constructs for bioactive compound delivery. Nanotechnology in the form of nanoparticles, used as a stand-alone construct or for material enhancements, can significantly improve established biomaterials such as PMMA based bone cements or enable new technology to have enhanced capabilities. Combinations of the technologies can be used in such applications as infectious disease treatments, chemotherapeutic targeted drug delivery or targeted delivery of nearly any bioactive compound.

Chemotherapeutic or antibiotic enhanced 3D printing filaments were …

Master's In Electrical Engineering, Ricardo Xavier Rodriguez

Open Access Theses & Dissertations

This project is a focus on characterizing the process for actualizing three dimensional structures out of a carbon nanostructure composite via a direct print additive manufacturing process. Manufacturing parts additively enables for realization of geometrically complex shapes that often times cannot be manufactured any other way. The specificity of a material's properties have to be such, that the processing method can precisely place and bond material to itself in a highly repeatable manner. Commercial materials for additive manufacturing are have been optimized with these goals in mind and, therefore, often times lack the rigor and robustness for many applications.

The …

3d Printed Spatially Variant Metamaterials, Cesar Roman Garcia

Open Access Theses & Dissertations

The recent advancement in 3D printing has created a new way to design electronics and electromagnetic devices. This allows for a new breed of non-planar designs to be used, fully exploiting all three dimensions like never before. More functions can be fit into the same amount of space, products with novel form factors can be more easily manufactured, interconnects can be routed more smoothly, interfaces can be better implemented, electrical and mechanical functions can be comingled, and entirely new device paradigms will be invented. When departing from traditional planar topologies many new problems arise like signal integrity, crosstalk, noise, and …