Manufacturing Commons^™

Hypoxic Incubation Chamber, Simone Lisette Helfrich, Makenzie Nicole Jones

Master's Theses

This paper describes the design, manufacturing, and testing of a novel controllable hypoxic incubator with fully functional oxygen gas control and temperature control in a humid environment. On the current market, a majority of the few hypoxic incubators use pre-mixed gas that does not offer precise control over gas concentration. The objective for this project was to create a chamber that allows the user to set the O2 concentration to varying set points of % O2 while maintaining the chamber at a constant body temperature, CO2 level, humidity, and sterility. To start the project, multiple concepts were developed for the …

Design Of A Proprioceptive Actuator Utilizing A Cycloidal Gearbox, Craig John Kimball

Master's Theses

Legged robotics creates the demand for high torque compact actuators able to develop high instantaneous torque. Proprioceptive actuator design theory is a design theory that removes the need for a torque feedback device and relies on the stiffness in the leg for absorbing the high Ground Impact Forces created by walking locomotion. It utilizes a high torque density motor paired with a gearbox with a high gear ratio for torque multiplication. Previously work has been done to design a proprioceptive actuator design that utilizes a planetary gearbox to create a modular low-cost actuator for legged robotics. The purpose of this …

Benchmark Testing Of Gold Ribbon Bonds On Thin-Film Microchips With New Gold Ribbon Auto-Bonder, Austin Conrad

Master's Theses

The focus of this document is on the gold ribbon bond testing and creation of a bonding map for the new gold ribbon Auto-Bonder at Keysight Technologies in Santa Rosa, California. The new Auto-Bonder replaces a nearly 50-year-old machine that no longer had any documentation for the original process of thin-film microchip ribbon bonding. The original process was developed in the early 1970s to provide an electrical connection from the top to the bottom of the microchip. The electrical connection takes the place of what would be a via in a modern silicon microchip. Gold wire bonding is a common …

Simulating Particle Packing During Powder Spreading For Selective Laser Melted Additive Manufacturing Using The Discrete Element Method In Abaqus, Priscilla Ng

Master's Theses

Metal additive manufacturing allows for the rapid production of complex parts that are otherwise impractical using conventional subtractive manufacturing techniques. Applications for additive manufacturing span across a broad array of industries including aerospace, automotive, and medical, among many others. One metric of printing success is material properties, including part density. While there has been extensive research completed for the density of printed parts, there is little published work concerning powder packing density on the build plate associated with powder spreading.

In this thesis, a Discrete Element Method (DEM) model was created in Abaqus to simulate the spreading behavior of particles …

Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz

Master's Theses

Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to …

Investigation Of Design, Manufacture, Analysis, And Test Of A Composite Connecting Rod Under Compression, Thomas Juhl Rohrbach

Master's Theses

Composite materials hold great potential for the replacement of traditional materials in machines utilized on a daily basis. One such example is within an engine block assembly where massive components inherently reduce the efficiency of the system they constitute. By replacing metal elements such as connecting rods, cylinder caps, or a crank shaft with composite alternatives, a significant increase in performance may be achieved with respect to mechanical strength, thermal stability, and durability, while also reducing mass. Exploration of this technology applied to a connecting rod geometry was investigated through a combination of process development, manufacturing, numerical analysis and testing. …

Defect Detection In Selective Laser Melting, Moira Foster

Master's Theses

Additively manufactured parts produced using selective laser melting (SLM) are prone to defects created during the build process due to part shrinkage while cooling. Currently defects are found only after the part is removed from the printer. To determine whether cracks can be detected before a print is completed, this project developed print parameters to print a test coupon with inherent defects – warpage and cracking. Data recorded during the build was then characterized to determine when the defects occurred.

The test coupon was printed using two sets of print parameters developed to control the severity of warpage and cracking. …

Mechanical Characterization Of Selectively Laser Melted 316l Stainless Steel Body Centered Cubic Unit Cells And Lattice Of Varying Node Radii And Strut Angle, Christopher James Hornbeak

Master's Theses

An experimental study of several variants of radius and strut angle of the body centered cubic unit cell was performed to determine the mechanical properties and failure mechanisms of the mesostructure. Quasi static compression tests were performed on an Instron® universal testing machine with a 50kN load cell at 0.2mm/min. The test samples were built using a SLM Solutions 125 selective laser melting machine with 316L stainless steel. Test specimens were based on 5mm cubic unit cells, with a strut diameter 10% of the unit cell size, with skins on top and bottom to provide a cantilever boundary constraint. Specimens …

Manufacture Of Complex Geometry Component For Advanced Material Stiffness, David Russell Bydalek

Master's Theses

The manufacture, laminate design, and modeling of a part with complex geometry are explored. The ultimate goal of the research is to produce a model that accurately predicts part stiffness. This is validated with experimental results of composite parts, which refine material properties for use in a final prototype part model. The secondary goal of this project is to explore manufacturing methods for improved manufacturability of the complex part. The manufacturing portion of the thesis and feedback into material model has incorporated a senior project team to perform research on manufacturing and create composite part to be used for experimental …

Characterization Of Flexible Hybrid Electronics Using Stretchable Silver Ink And Ultra-Thin Silicon Die, Joshua A. Ledgerwood

Master's Theses

Flexible Hybrid Electronics (FHEs) offer many advantages to the future of wearable technology. By combining the dynamic performance of conductive inks, and the functionality of ultra-thinned, traditional IC technology, new FHE devices allow for development of applications previously excluded by relying on a specific type of electronics technology.

The characterization and reliability analysis of stretchable conductive inks paired with ultra-thin silicon die in theµm range was conducted. A silver based ink designed to be stretchable was screen printed on a TPU substrate and cured using box oven, conveyor convection oven, and photonic curing processes. Reliability tests were conducted including a …

Design And Testing Of A Top Mask Projection Ceramic Stereolithography System For Ceramic Part Manufacturing, Dylan Robert De Caussin

Master's Theses

Ceramic manufacturing is an expensive process with long lead times between

the initial design and final manufactured part. This limits the use of ceramic as a viable material unless there is a large project budget or high production volume associated with the part. Ceramic stereolithography is an alternative to producing low cost parts through the mixing of a photo curable resin and ceramic particles. This is an additive manufacturing process in which each layer is built upon the previous to produce a green body that can be sintered for a fully dense ceramic part.

This thesis introduces a new approach …

Process Development For Compression Molding Of Hybrid Continuous And Chopped Carbon Fiber Prepreg For Production Of Functionally Graded Composite Structures, Corinne Marie Warnock

Master's Theses

Composite materials offer a high strength-to-weight ratio and directional load bearing capabilities. Compression molding of composite materials yields a superior surface finish and good dimensional stability between component lots with faster processing compared to traditional manufacturing methods. This experimental compression molding capability was developed for the ME composites lab using unidirectional carbon fiber prepreg composites. A direct comparison was drawn between autoclave and compression molding methods to validate compression molding as an alternative manufacturing method in that lab. A method of manufacturing chopped fiber from existing unidirectional prepreg materials was developed and evaluated using destructive testing methods. The results from …

Material Characterization And The Effects Of Moisture And Drying On Injection Molded Torlon 5030, Michael R. Di Re

Master's Theses

The effects of water absorption and drying were studied on injection molded Torlon 5030, a high performance thermoplastic fabricated by Solvay Specialty Polymers. Torlon 5030 contains 30% by weight glass fibers in a polyamide-imide base resin. The objective behind this work was to test and better define relevant properties for industrial applications using this material. While the material design guide offers information on many mechanical properties including tensile, fatigue, and creep data; there is little to no publicly published data on the effects of water absorption and any subsequent drying of Torlon 5030. Blistering was also studied. With exposure to …

Advanced Design Optimization For Composite Structure: Stress Reduction, Weight Decrease And Manufacturing Cost Savings, Shayan Ahmadian

Master's Theses

An injection moldable chopped fiber composite actuator with detailed drawing and tolerances was designed within one year. A vendor was selected and a quote for injection molding tooling cost for production was obtained and the first prototype was built in addition of six months. The risks are identified and material characterization tests are proposed.

The objective of this project was redesigning an aluminum made actuator with a continuous fiber composite for weight saving purposes. After searching the literature and consulting with experts in the field it was concluded that manufacturing costs associated with continuous fiber composite are 3 times as …

The Design And Fabrication Of A Microfluidic Reactor For Synthesis Of Cadmium Selenide Quantum Dots Using Silicon And Glass Substrates, Peter Robert Gonsalves

Master's Theses

A microfluidic reactor for synthesizing cadmium selenide (CdSe) quantum dots (QDs) was synthesized out of a silicon wafer and Pyrex glass. Microfabrication techniques were used to etch channels into the silicon wafer. Holes were wet-drilled into the Pyrex glass using a diamond-tip drill bit. The Pyrex wafer was anodically bonded to the etched silicon wafer to enclose the microfluidic reactor. Conditions for anodic bonding were created by exposing the stacked substrates to 300V at ~350oC under 5.46N of force. A syringe containing a room temperature CdSe solution was interfaced to the microfluidic reactor by using Poly (dimethylsiloxane) (PDMS) as an …

High-Resolution, Non-Contact Angular Measurement System For Psa/Rsa, Ronald D. Sloat

Master's Theses

A non-contact angular measurement system for Pitch Static Attitude (PSA) and Roll Static Attitude (RSA) of hard disk drive sliders is designed and built. Real-time sampling at over 15 KHz is achieved with accuracy of +/- 0.05 degrees over a range of approximately 2-3 degrees. Measuring the PSA and RSA is critical for hard drive manufacturers to control and improve the quality and reliability of hard drives. Although the hard drive industry is able to measure the PSA and RSA at the subassembly level at this time, there is no system available that is able to measure PSA/RSA at the …

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …