Engineering Commons^™

The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo

Electronic Theses and Dissertations

This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.

This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …

Femtosecond Pulse Filamentation In Dielectric Media Toward Photonics Sensor Fabrication, Anitha Narayanan

Theses and Dissertations

Through pulse filamentation, femtosecond laser pulses have been utilized to modify the refractive indices of dielectric materials such as glass, A-plane sapphire crystal, and Cplane sapphire crystal. The 10x Infinity Corrected Lens was used, and the focusing condition was tuned as being the same and fixed to both glass and sapphire crystals. First, 8uJ of laser energy was optimized to produce controlled pulse filamentation voids in the glass. The laser intensity was then optimized to 2-3.5 uJ, 1.5 uJ, & 2.5 uJ, respectively, for the controlled pulse filamentation in A and C plane sapphire crystals. Due to the different crystal …

Design And Fabrication Of Invar Layup Tool Molds Using Additive And Subtractive Manufacturing, Matthew Lamsey

Masters Theses

The development of novel additive manufacturing technologies, such as Wire Arc Additive Manufacturing (WAAM), has opened the door for the fabrication of complex part geometries that could not be achieved with traditional manufacturing methods. Best practices for designing parts for fabrication with WAAM are still in their infancy. This thesis presents a novel design and fabrication framework for parts created using WAAM, which was realized through the fabrication of two demonstration composite layup tool molds. The framework includes design principles for WAAM, finite element simulation of part performance, metrological analysis of printed preforms, and considerations for closely integrating the WAAM …

Design, Fabrication, And Testing Of A High-Speed, Low-Cost Atomic Force Microscope Housing And Distance Measurement System, Jonathan Menke

All Undergraduate Theses and Capstone Projects

Advances to the state-of-the-art in fields like biology and material science often stand on the foundation of improved imaging. Here a low-cost Atomic Force Microscope (AFM) housing and distance measurement system was designed, fabricated, and tested. The instrument was developed around an Optical Pickup Unit (OPU) and designed for use as part of a high-speed AFM system. A structure to align the OPU with the probe holder was designed to ensure the beam of the OPU is positioned above the probe in addition to accommodating space, manufacturability, and cost constraints by using cost effective components. The designs were fabricated and …

Design And Fabrication Of A 3-Dimensional Capacitive-Based Force Sensor, Md Shafiqur Rahman

Electronic Theses and Dissertations

The detection of abnormal gait patterns is imperative for early diagnoses and treatment of serious health issues such as loss of mobility and balance, risk of falls, cardiovascular disease, etc. Human gait analysis is the tool used to detect abnormal gait patterns. Gait analysis also can help to understand the cause of gait abnormalities and to make a treatment plan for individual patients. Ground reaction forces (GRFs) at the foot during walking or running are essential for kinetic analysis of the human gait. However, there are no wearable systems that can directly measure three-directional (3D) forces during daily walking. Currently, …

Development Of An Anatomically And Electrically Conductive Brain Phantom For Transcranial Magnetic Stimulation, Hamzah A. Magsood

Theses and Dissertations

Transcranial Magnetic Stimulation (TMS) is a non-invasive technique for diagnostics, prognostic, and treatments of various neurological diseases. However, the lack of anatomically realistic brain phantoms has made the experimental verification of stimulation strength in the form of induced electric fields/voltages in the brain tissues an impediment to developing new TMS coils, stimulators, and treatment protocols. There are significant technological, safety, and ethical limitations to test the potential TMS treatment procedures or develop enhancements and refine them on humans or animals. This work aims to bridge the gap by introducing and developing an innovative manufacturing and fabrications process to produce a …

Custom Designed Wall Mounted Shop Crane, Bradley Lewis

All Undergraduate Projects

The objective of this project was to design and fabricate a custom wall mounted jib crane to specific, non-standard dimensions. The crane was designed to be industry rated for 2000 pounds, rotate at least 180 degrees, and be designed to have a maximum boom length tailored to the specific installation site. Two potential installation sites and purposes were selected for construction: inside the bay doors of a fabrication shop, intended to transfer large pieces of material to and from a plasma table, and inside a car maintenance garage, intended to lift and remove engines and transmissions from cars.

Design of …

Functional Optimization Of Carbon Nanotubes, Taylor Davis, Sr. Brian Iverson

Journal of Undergraduate Research

The objective of this project was to create, characterize, and optimize carbon nanotube (CNT) films as a surface functionalization strategy through modifying the growth, infiltration, and patterning during fabrication.

Carbon nanotubes have drawn attention in various disciplines in the scientific community because of their incredible strength, hardness, wettability (hydrophobicity), as well as their kinetic and electrical properties. At BYU specifically, they are being used in diverse applications including fabrication of superhydrophobic surfaces and interdigitated electrode biosensors.

Carbon nanotubes can be delicate with a diameter of only a few nanometers when grown. However, the process of carbon infiltration can be used …

Azelia's Walker, Jordan C. Ramsey, Kathleen C. Balfour, Jayne K. Benedict, Gabrielle Merkin

Mechanical Engineering

A Biomedical Engineering student, KC Balfour, two Mechanical Engineering students, Jayne Benedict and Gabrielle Merkin, and one Industrial Engineering student, Jordan Ramsey, make up the interdisciplinary senior project team of Azelia’s Walker. The goal of Azelia’s Walker is to create a custom walker for an 8-year-old girl in the San Luis Obispo Community, named Azelia, who has decreased motor control. Her current walker does not suit her active and energetic lifestyle, so Azelia’s Walker is challenged to design and manufacture a collapsible all-terrain walker that best suits Azelia’s needs. Throughout the academic year, Azelia’s Walker participated in the brain-storming and …

H.F. Hauff Outrigger: Vertical Arm, Juan Tovar

All Undergraduate Projects

H.F. Hauff is a company based out of Yakima which specializes in farming equipment. One of their products is a trailer which has a wind machine attached to it. In order to keep the fan’s thrust from tipping the trailer over, the trailer needs outriggers to extend out. The outriggers also serve as a way to level out the trailer in uneven surfaces. The outriggers are what needed to be designed. This portion of the project was the vertical arm which extends from the horizontal arm, and goes towards the ground to raise the trailer. The project consisted of three …

Multi-Axis Multi-Material Fused Filament Fabrication With Continuous Fiber Reinforcement, Wout De Backer

Theses and Dissertations

Additive Manufacturing (AM) has become a well-recognized method of manufacturing and has steadily become more accessible as it allows designers to prototype ideas, products and structures unconceivable with subtractive manufacturing techniques for both consumer grade and industrial grade applications. Commonly used thermoplastics for 3D printing have properties that may not be sufficient to comply with the application’s certification requirements, or their performance is less than desirable for aerospace and other high performance applications. Additionally, additively manufactured parts have reduced mechanical properties in the build direction of the print, and are generally weaker than their equivalent injection-molded parts. Furthermore, Computer Aided …

An Engineering Approach To Industrial Research And Development Of Pillows, Wesley Patterson

Mahurin Honors College Capstone Experience/Thesis Projects

Comfort during sleep, though taken for granted, involves a great amount of research and engineering. Few give it a second thought, but nearly one-third of a person’s life is spent with their head on a pillow, thus making them a point for increased quality. Having been approached by a tier-1 bedding manufacturer, a team of both mechanical and electrical engineers was been tasked with the goal of creating a valid research tool that the customer, Tempur-Sealy, will utilize in the company’s research and development of high-end pillows. The team sought to tackle this project utilizing tools and knowledge gained throughout …

Orchard Bin Atv Trailer, Neil F. Leitz

All Undergraduate Projects

A local orchardist was experiencing a problem that was being caused by their lack of apple picking bin moving equipment. The orchardist needed a well-engineered solution to this lack of equipment. The solution arrived at was a five bin trailer. There were multiple design requirements for this trailer, including the device needing to be able to interface with an ATV, be able to be loaded by hand, be able to carry five bins, and not exceed a budget of $750. While perfecting the design of the trailer, a number of different disciplines were utilized, which included dynamics, kinematics, static loading …

Dynamometer Stabilizer, Derek A. Lamarche

All Undergraduate Projects

Overhauling the CWU small engine Dynamometer in the CWU power lab will make it more ridged during the measurement of power in these engines. The goal of the project is to have the dyno used in the Small engines class run by a staff member and to be run by the students. The dynamometer does not work within the specified limits making it impractical to perform during lab

Methods Of Extrusion On Demand For High Solids Loading Ceramic Paste In Freeform Extrusion Fabrication, Wenbin Li, Amir Ghazanfari, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Fabrication of highly dense parts with complex geometry by paste-extrusion-based solid freeform fabrication processes requires a precise control of the extrusion flow rate to dispense material on demand, which is often referred as Extrusion-On-Demand (EOD). The extrusion process for aqueous ceramic pastes is complex and difficult to control due to their non-Newtonian behavior, compressibility and inhomogeneity. In this study, three methods of EOD (based on ram extruder, needle valve, and auger valve) are introduced and investigated for the extrusion of high solids loading (i.e., > 50%, volumetric) aqueous alumina paste. Optimal extrusion process parameters for these methods are determined through printing …

Dc-Gain Layer-To-Layer Stability Criterion In Laser Metal Deposition Processes, Patrick M. Sammons, Douglas A. Bristow, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In Laser Metal Deposition (LMD), a blown powder metal additive manufacturing process, functional metal parts are fabricated in a layer-by-layer fashion. In addition to the in-layer dynamics, which describe how the process evolves within a given layer, the additive-fabrication property of LMD creates a second set of dynamics which describe how the process evolves from layer-to-layer. While these dynamics, termed layer-to-layer dynamics, are coupled with both the in-layer dynamics and the process operating conditions, they are not widely considered in the modeling, process planning, or process control of LMD operations. Because of this, seemingly valid choices for process parameters can …

Feasibility Study Of Custom Manufacturing Of Ionic Polymer-Metal Composite Sensors, Shelby E. Nelson

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ability to create an ion exchange membrane with any shape or thickness through custom manufacturing techniques is highly desirable in ionic polymer-metal composite (IPMC) research. This is caused by the poor selection and limited availability of certain thicknesses of commercial ion exchange membranes. The objective of this study is to determine the feasibility of manufacturing custom ion exchange membranes for IPMC sensors. The manufacturing methods used in this study are extrusion, injection molding, and hot pressing. A commercial membrane from Golden Energy Fuel Cells (GEFC) is used as a comparison. After the membranes are fabricated, certain properties of the …

Tailoring Zno Nanostructures By Spray Pyrolysis And Thermal Annealing

Faculty of Engineering University of Malaya

We report a novel synthesis of ZnO nanorods with hexagonal pyramid-like heads by a simple and low cost technique of spray pyrolysis with the help of zinc acetate and tin (IV) chloride pentahydrate precursors. In the present study, the growth of ZnO nanorods is optimized by varying a number of sprays and annealing temperatures in the synthesis process. FESEM analysis reveals that ZnO nanorods are observed when the number of sprays exceeds 150 and film-like structure is observed below 150 sprays. Nanorods are formed when the molar ratio of zinc acetate to tin (IV) chloride pentahydrate in the solution mixture …

Tio2 Nanotube Coating On Stainless Steel 304 For Biomedical Applications

Faculty of Engineering University of Malaya

The present study describes the anodic growth of TiO2 nanotube thin layer on stainless steel 304 in ethylene glycol/water/ammonium fluoride electrolyte. In this regard, pure titanium was coated on stainless steel 304 substrates by a physical vapor deposition magnetron sputtering (PVDMS) technique. The adhesion strength of the coating to the substrate was investigated. TiO2 nanotubes were generated on the top of the Ti coated substrates by means of anodization technique at a 25 V potential and times of 20, 40, and 60 min in an ammonium fluoride electrolyte solution. The anodized Ti-coated samples were heat-treated at 280 degrees C, 430 …

An Investigation Of The Effect Of Direct Metal Deposition Parameters On The Characteristics Of The Deposited Layers, Tarak A. Amine, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

Multilayer direct laser deposition (DLD) is a fabrication process through which parts are fabricated by creating a molten pool into which metal powder is injected as particles. During fabrication, complex thermal activity occurs in different regions of the build; for example, newly deposited layers will reheat previously deposited layers. The objective of this study was to provide insight into the thermal activity that occurs during the DLD process. This work focused on the effect of the laser parameters of newly deposited layers on the microstructure and mechanical properties of the previously deposited layers in order to characterize these effects to …

Modification Of A Draw Bar Type Arena Harrow To Three Point Mounted Type Harrow, Clayton Alan Brown

BioResource and Agricultural Engineering

This senior project will be the design, and construction of a three point hitch to be attached to a draw bar type spike tooth harrow. Currently used by the Cal Poly Rodeo Team to cultivate their arena before performances, and practices.

The attachment will allow the harrow to be pulled in both directions to create different types of soil affects.

Also the fabrications has a minimal budget so the majority of the materials will be scrap material already in position of the rodeo team or donated to the project.

S&G Metal Fab Battery Tray, Matthew Nartatez

Industrial and Manufacturing Engineering

This report was written for the design of a battery tray and manufacturing process for S&G Metal Fab. The manufacturing steps of how to process the sheet metal to create the product are defined and documented in this report. This project began with constraints given by S&G and were all accomplished using coursework knowledge obtained as a manufacturing engineer student at Cal Poly San Luis Obispo. This report mainly covers parameters regarding the cutting, bending and, deforming of sheet metal to acquire the desired shapes and sizes. It also analyzes the costs that are associated with these processes and material. …

Freeze-Form Extrusion Fabrication Of Functionally Graded Material Composites Using Zirconium Carbide And Tungsten, Ang Li, Aaron S. Thornton, Bradley K. Deuser, Jeremy Lee Watts, Ming-Chuan Leu, Greg Hilmas, Robert G. Landers

Materials Science and Engineering Faculty Research & Creative Works

Ultra-high-temperature ceramics are being investigated for future use in aerospace applications due to their superior thermo-mechanical properties, as well as their oxidation resistance, at temperatures above 2000⁰C. However, their brittleness makes them susceptible to thermal shock failure. As graded composites, components fabricated as functionally-graded materials (FGMs) can combine the superior properties of ceramics with the toughness of an underlying refractory metal. This paper discusses the grading of two materials through the use of a Freeze-form Extrusion Fabrication (FEF) system to build FGM parts consisting of zirconium carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and W were developed …

Direct Write Fabrication Of Waveguides And Interconnects For Optical Printed Wiring Boards, Joseph Carl Dingeldein

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

Current copper based circuit technology is becoming a limiting factor in high speed data transfer applications as processors are improving at a faster rate than are developments to increase on board data transfer. One solution is to utilize optical waveguide technology to overcome these bandwidth and loss restrictions. The use of this technology virtually eliminates the heat and cross-talk loss seen in copper circuitry, while also operating at a higher bandwidth. Transitioning current fabrication techniques from small scale laboratory environments to large scale manufacturing presents significant challenges. Optical-to-electrical connections and out-of-plane coupling are significant hurdles in the advancement of optical …

Freeze-Form Extrusion Fabrication Of Composite Structures, Ming-Chuan Leu, Lie Tang, Bradley K. Deuser, Robert G. Landers, Greg Hilmas, Shi C. Zhang, Jeremy Lee Watts

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A Freeze-form Extrusion Fabrication (FEF) process capable of making three-dimensional (3D) parts and structures with graded composite materials is presented in this paper. The process development includes the design and manufacture of a gantry machine with a triple-extruder mechanism and the associated electronics hardware and computer software for fabricating functionally graded parts from multiple aqueous pastes. A rheological behavior study with Al₂O₃ paste is performed to identify an efficient binder for transforming the paste into a pseudoplastic with a high yield stress. A green part is first fabricated using the triple-extruder FEF machine in a layer-by-layer manner …

Simulation And Fabrication Of Three Novel Micromechanical Sensors, Yanqing Lu

Doctoral Dissertations

This work focuses on the simulation, fabrication and characterization of novel microdevices for chemical and biological sensors for improved sensitivity, enhanced performance and applicability. Specifically, microbridge and microcoil sensors have been fabricated via advanced microfabrication technologies. Due to the potential application in chemical and biological sensing, the growth of gold and platinum nanowires during an electrolysis process have also been investigated.

A microbridge can be considered as the head-to-head fusion of two cantilevers and the middle of the bridge would deform in a way similar to a microcantilever. The microbridge sensing device is more stable than the microcantilever, especially in …

Experimental Investigation Of Effect Of Environment Temperature On Freeze-Form Extrusion Fabrication, Xiyue Zhao, Michael S. Mason, Tieshu Huang, Ming-Chuan Leu, Robert G. Landers, Greg Hilmas, Samuel J. Easley, Michael W. Hayes

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing technique that extrudes ceramic loaded aqueous pastes layer by layer below the paste freezing temperature for component fabrication. A computer controlled 3-D gantry system has been developed for the FEF process. The system includes a temperature control subsystem that allows for fabrication of components below the paste freezing temperature. The low temperature environment allows for larger component fabrication. Comparisons in terms of layer thickness, self-sustaining ability, and system response were performed between 0⁰C and -20⁰C for alumina sample fabrications. The minimum deposition angles without use of support material have been determined for …

Freeze-Form Extrusion Fabrication Of Ceramics, Tieshu Huang, Michael S. Mason, Greg Hilmas, Ming-Chuan Leu

Materials Science and Engineering Faculty Research & Creative Works

A novel, environmentally friendly solid freeform fabrication method called Freeze-form Extrusion Fabrication (FEF) has been developed for the fabrication of ceramic-based components. The method is based on deposition of ceramic pastes using water as the media. The ceramic solids loading can be 50 vol. % or higher and initial studies have focused on the use of aluminum oxide (Al₂O₃). The FEF system components and their interaction are examined, and the main process parameters affecting part geometry defined. 3-D shaped components have been fabricated by extrusion deposition of the ceramic paste in a layer-by-layer fashion. The feasibility …

Fabrication Of Hollow Waveguides With Sacrificial Aluminum Cores, John P. Barber, Donald B. Conkey, Jeffrey Ryan Lee, Neal B. Hubbard, Larry L. Howell, Aaron R. Hawkins, Gongliang Yin, Holger Schmidt

Faculty Publications

We have developed a process to fabricate dielectric waveguide structures with long hollow cores formed by etching a sacrificial core material. The process is compatible with other planar silicon fabrication techniques. Using aluminum as the sacrificial material, we have investigated fabrication limits and design parameters that determine mechanical integrity of the waveguides. Internal pressure due to the production of gaseous compounds during the core removal process was identified as the yield-limiting factor. A mechanical model based on finite element analysis and confirmed by experiment, predicts ultimate pressures sustainable by these structures. Waveguides less than 10 m wide with 2- m-thick …