Mechanical Engineering Commons^™

The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden

Theses and Dissertations

Over the life of nuclear fuel, inhomogeneous structures develop, negatively impacting thermal properties. New fuels are under development, but require more accurate knowledge of how the properties change to model performance and determine safe operational conditions. Measurement systems capable of small–scale, pointwise thermal property measurements and low cost are necessary to measure these properties and integrate into hot cells where electronics are likely to fail during fuel investigation. This project develops a cheaper, smaller, and easily replaceable Fluorescent Scanning Thermal Microscope (FSTM) using the blue laser and focusing circuitry from an Xbox HD-DVD player. The FSTM also incorporates novel fluorescent …

Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor

Theses and Dissertations

Developing lifelike vocal fold models is challenging due to various associatedbiomechanical complexities. Nevertheless, the development and analysis of improved vocal foldmodels is worthwhile since they are valuable tools for gaining insight into human vocal foldvibratory, aerodynamic, and acoustic response characteristics. This thesis seeks to contribute tothe development of computational and physical vocal fold modeling in two ways. First is byintroducing a method of obtaining internal deformation fields within vibrating synthetic vocal foldmodels; second is by presenting an optimization algorithm coupled with a computational vocalfold model to optimize geometry and stiffness of a synthetic vocal fold model to achieve morerealistic vibration …

Using Non-Destructive Testing To Predict Bending Modulus Of Carbon Infiltrated-Carbon Nanotubes, Fred Stile Fagergren

Theses and Dissertations

Fabrication of carbon infiltrated carbon nanotubes (CI-CNT) can result in large mechanical property variation, and methods to characterize properties usually involve destructive testing. Finding a non-destructive way to test for stiffness of this material reduces the number of parts that have to be made. It also simplifies testing of complex parts. The stiffness of CI-CNT beams is related to the type of carbon material infiltrated between the carbon nanotubes (CNTs), how it interacts with the CNTs, and how much of it there is. The amount of material can be estimated using the density of the beam, and both the type …

5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj

Theses and Dissertations

Knowledge of the full 5-degree Grain Boundary Character Distribution (GBCD) is vital to understanding properties, such as gas diffusivity, that are dominated by grain boundary character. Surface characterization techniques, such as Electron Backscattered diffraction (EBSD), can provide only 4 of the 5 GB characteristics (the rotation between the neighboring grains, and the trace of the GB on the surface). The inclination of the GB in the direction normal to the surface is not known. A previous study indicated that the GB inclination could be recovered by correlating the Electron Backscattered patterns (EBSPs) of sample points near the GB with EBSPs …

Wall Shear Stress In Simplified And Scanned Avian Respiratory Airways, Michael Sterling Farnsworth

Theses and Dissertations

Birds uniquely produce sound through a vocal organ known as a syrinx. The presence of wall shear stress acting on the airway cells of any organism will affect how airway cells develop and multiply. Unique features of avian airway geometry and breathing pattern might have contributed to the development of the syrinx. This thesis examines wall shear stress in the trachea and first bronchi of avian geometries using computational fluid dynamics. The computational fluid dynamic simulations underwent grid- and time-independence studies and were validated using particle image velocimetry. Parameters such as bird size, bronchial branching angle, and breathing waveform were …

Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson

Theses and Dissertations

An investigation of IsoTruss structures in bending and torsion was conducted. A model was developed in ANSYS APDL where bay length and longitudinal member to helical member cross-sectional area ratio could be varied while holding the diameter constant. The model was validated using previously reported values from analytical models and empirical data. The model was used to make predictions of a specific geometry that was manufactured, tested and compared against the model. 12 specimens were built and tested. In flexure, empirical data had a percent error with respect to the model ranging from 10.9 to 65.4% with one outlier at …

Origami-Based Design Of Fold States And Stability, Alex Avila

Theses and Dissertations

Origami is a potentially elegant and powerful source of inspiration for many engineering designs. The viable shapes (fold states) of a single device allow it to perform multiple, seemingly contradictory, functions. The fold state is a large factor in the device's performance, but there are challenges in selecting and maintaining those fold states. In this thesis we analyze existing concepts for overcoming these challenges. Those concepts are compared with those that occur in origami-based devices. From this analysis fundamental gaps were identified, specifically, shortcoming in the terminology used to refer to (1) non-flat origami states and (2) sets of facets …

Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau

Theses and Dissertations

Human knee kinematics, especially during gait, are an important analysis tool. The current "gold standard" for kinematics measurement is a multi-camera, marker-based motion capture system with 3D position tracking. These systems are accurate but expensive and their use is limited to a confined laboratory environment. High deflection strain gauges (HDSG) are a novel class of sensors that have the potential to measure kinematics and can be inexpensive, low profile, and are not limited to measurements within a calibrated volume. However, many HDSG sensors can have a non-linear and non-monotonic response. This thesis explores using a nanocomposite HDSG sensor system for …

Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick

Theses and Dissertations

Metallic glass matrix composites (MGMCs) have been developed to improve upon the ductility of monolithic metallic glass. These composites utilize a secondary crystalline phase that is grown into an amorphous matrix as isolated dendritic trees. This work seeks to understand the mechanisms underlying strain delocalization in MGMCs in order to better direct efforts for continual progress in this class of material. A mesoscale modelling technique based on shear transformation zone (STZ) dynamics is used to do so. STZ dynamics is a coarse grained technique that can provide insight into the microscopic processes that control macroscopic behavior, but which can be …

Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore

Theses and Dissertations

While vertical takeoff and landing aircraft show promise for urban air transport, distributed electric propulsion on existing aircraft may offer an immediately implementable alternative. Dis- tributed electric propulsion has the potential of increasing the aircraft thrust-to-weight ratio and lift coefficient high enough to enable takeoff distances of less than 100 meters. While fuel based propulsion technologies generally increase in specific power with increasing size, electric propul- sion typically can be decreased in size without a decrease in specific power. The smaller but highly power-dense propulsion units enable alternative designs including many small units, optionally powered units, and vectored thrust from …

Frequency Response Of The Leap Motion Controller And Its Suitability For Measuring Tremor, Clay J. Kincaid, Austin C. Vaterlaus, Nathan R. Stanford, Steven Knight Charles

Faculty Publications

Although tremor is one of the most common movement disorders, it is evaluated using relatively coarse clinical scales. We propose to measure tremor in clinical settings using the Leap Motion Controller (LMC), which is a markerless motion capture sensor that has a low cost, zero set-up time, and dynamic accuracy of 1.2mm. However, the frequency response of the LMC has not been characterized, so its ability to track oscillations such as tremor is unknown. To characterize the frequency response of the LMC, we measured the position of a mannequin hand simultaneously with the LMC and a high-resolution encoder while the …

Dynamic Optimization Of High-Altitude Solar Aircraft Trajectories Under Station-Keeping Constraints, Abraham Martin, Nathaniel Gates, Andrew Ning, John Hedengren

Faculty Publications

This paper demonstrates the use of nonlinear dynamic optimization to calculate energy- optimal trajectories for a high-altitude, solar-powered Unmanned Aerial Vehicle (UAV). The objective is to maximize the total energy in the system while staying within a 3 km mission radius and meeting other system constraints. Solar energy capture is modeled using the vehicle orientation and solar position, and energy is stored both in batteries and in potential energy through elevation gain. Energy capture is maximized by optimally adjusting the angle of the aircraft surface relative to the sun. The UAV flight and energy system dynamics are optimized over a …

Cip2a Immunosensor Comprised Of Vertically-Aligned Carbon Nanotube Interdigitated Electrodes Towards Point-Of-Care Oral Cancer Screening, Shaowei Ding, Suprem R. Das, Benjamin J. Brownlee, Kshama Parate, Taylor Davis, Loreen R. Stromberg, Edward K.L. Chan, Joseph Katz, Brian D. Iverson, Jonathan C. Claussen

Faculty Publications

Vertically aligned carbon nanotube array (VANTA) coatings have recently garnered much attention due in part to their unique material properties including light absorption, chemical inertness, and electrical conductivity. Herein we report the first use of VANTAs grown via chemical vapor deposition in a 2D interdigitated electrode (IDE) footprint with a high height-to-width aspect ratio (3:1 or 75:25 µm). The VANTA-IDE is functionalized with an antibody (Ab) specific to the human cancerous inhibitor PP2A (CIP2A)—a alivary oncoprotein that is associated with a variety of malignancies such as oral, breast, and multiple myeloma cancers. The resultant immunosensor is capable of detecting CIP2A …

Coordinated, Multi-Arm Manipulation With Soft Robots, Dustan Paul Kraus

Theses and Dissertations

Soft lightweight robots provide an inherently safe solution to using robots in unmodeled environments by maintaining safety without increasing cost through expensive sensors. Unfortunately, many practical problems still need to be addressed before soft robots can become useful in real world tasks. Unlike traditional robots, soft robot geometry is not constant but can change with deflation and reinflation. Small errors in a robot's kinematic model can result in large errors in pose estimation of the end effector. This error, coupled with the inherent compliance of soft robots and the difficulty of soft robot joint angle sensing, makes it very challenging …

Deep Rc: Enabling Remote Control Through Deep Learning, Jaron Ellingson, Gary Ellingson, Tim Mclain

Student Works

Human remote-control (RC) pilots have the ability to perceive the position and orientation of an aircraft using only third-person-perspective visual sensing. While novice pilots often struggle when learning to control RC aircraft, they can sense the orientation of the aircraft with relative ease. In this paper, we hypothesize and demonstrate that deep learning methods can be used to mimic the human ability to perceive the orientation of an aircraft from monocular imagery.

This work uses a neural network to directly sense the aircraft attitude. The network is combined with more conventional image processing methods for visual tracking of the aircraft. …

Secondary Atomization During Droplet Impingement Of Water-Glycerol Admixtures On Heated Superhydrophobic Surfaces, Alexander White, Dr. Julie Crockett

Journal of Undergraduate Research

The purpose of the given document is to remind the reader of goals initially set in conjunction with the ORCA Grant project proposal in October 2016, to present experimental findings obtained during the grant period, and to discuss the results of the work and their implications for future investigations. As stated in the proposal, the main purpose of this ORCA project was to compare the droplet atomization (expulsion of a fine spray) of various water-glycerol mixtures upon impact on superheated, superhydrophobic surfaces. The major goal to that end was to use a certain unique experimental procedure in quantifying the data …

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 …

Static And Dynamic Obstacle Avoidance For Small Uav, Michael Farrell, Dr. Tim Mclain

Journal of Undergraduate Research

Unmanned aerial vehicles (UAV) are becoming increasingly prevalent in society today. One of the most important problems for such vehicles is obstacle avoidance. Common applications for small UAV require them to navigate through an environment containing many obstacles, both static and dynamic. As part of the 2017 SUAS-AUVSI undergraduate competition, this common problem was simulated with several virtual stationary and moving objects that were to be avoided during flight. The purpose of this research project was to develop a robust obstacle avoidance algorithm to be demonstrated during the mission demonstration of the 2017 SUAS-AUVSI competition.

Sunflowers, Solar Panels, And Beeswax: Improving Solar Power For The Developing World, Ivyann Oveson Running, Dr. John Salmon

Journal of Undergraduate Research

Inspired by the mechanics of how sunflowers follow the sun, we designed a system to increase output from solar panels by only using simple mechanics and beeswax. Solar power is becoming increasingly popular even in developing countries. We wanted to create a way to increase the power output of solar panels in such areas that lack technical support for current panel rotating mechanisms. When temperatures increase, beeswax expands, and we harness the motion by filling a piston with the beeswax. We use this motion to cause solar panels to turn, following the sun throughout the day and increasing electrical output.

Estimating Joint Configuration For Soft Robots, Jacob Olson, Dr. Marc Killpack

Journal of Undergraduate Research

Soft robotics are still a relatively new technology. As seen in Figure 1, they are made entirely from compliant materials that use pressurized fluid for both structure and actuation. These robots have great potential in the world of robotics. Soft robots can excel in many areas where rigid robots fall short due to their incredible compliance and low inertia. As soft robotic technologies develop, robots will be much less limited in the scope of what they can do without risk of human injury. They will be able to do tasks working more closely with humans in current industries, and be …

Refining Statistical Magnesium Models Via Machine Learning, Andrew Orme, Dr. David Fullwood

Journal of Undergraduate Research

Magnesium is a potential replacement for steels and aluminum in strength applications. Despite desirable strength and weight properties, magnesium is costly to manufacture. To reduce manufacturing costs, extensive research has been done on is a phenomenon called twinning, where a large group of magnesium atoms collectively reorient from a base orientation to a new orientation. This reorientation caused by twinning has the potential to enable easier material deformation, allowing for less costly manufacturing. Our research group pursued a novel approach to twinning research by using data mining and machine learning algorithms. Data collected from samples of magnesium using a scanning …

Rigidly Foldable Origami Flashers Based On Curved-Fold Model, Jacob Badger, Dr. Larry Howell

Journal of Undergraduate Research

The purpose of my research was to explore the application of curved folding in designing rigid-foldable deployable mechanisms. In recent years, origami fold patterns known as “flashers” have been investigated for their ability to efficiently pack deployable surfaces. While many patterns have been investigated, none are capable of folding surfaces composed of rigid panels that bend only along crease lines. We hoped to identify one such rigid-foldable flasher by basing it on a curved-fold pattern known as a logarithmic spiral flasher.

Above Knee Prosthetic Socket For Developing Countries, Colton Graham, Dr. Mark Colton

Journal of Undergraduate Research

Due to a civil war in Sierra Leone many have been left with amputated limbs. In order to provide the required prosthetic limbs for victims who have above the knee amputations they need a quality custom fit socket. Custom fit sockets are very expensive so we created a universal socket meant to comfortably fit everyone. This socket is also designed to be affordable and able to be manufactured in Sierra Leone. For a functional socket, it is to be custom fitted, durable, affordable, adjustable and comfortable for the amputee. Due to varying changes to the volume of the residual limb, …

Carbon Nanotube Filtration Device: Separating Oil From Fracking Waste, Phillip Ng, Dr. Anton Bowden

Journal of Undergraduate Research

Pyrolytic Carbon Infiltration Carbon Nanotubes (CI-CNTs) can isolate water and oil molecules due to its superhydrophobic and oleophilic properties, unique cylindrical nanostructure, and functional groups¹. Because the waste produced from fracking is nonreusable due to the molecular oil droplets contained in it, the waste is typically injected back underground, which pollutes safe drinking water². This can be avoided with an inexpensive and efficient oil and water filter. The mentored research project revolved around a CI-CNT filter used to salvage waste created from fracking.

The design of a CI-CNT device was approached by three main considerations: a …

Gas Detection System For Biomass Cookstove Emissions, Cyra Bishop, Jeffery Smith, Dr. Matthew Jones

Journal of Undergraduate Research

The purpose of this research project is to explore Peruvian social and cultural behaviors that typically prevent successful improved cookstove adoption in resource-limited settings as well as suggest ways to educate locals about the benefits of improved cookstoves. This will be done by constructing a cost-effective, easy-to-use gas-detection sensor system capable of measuring concentrations of harmful gases released from biomass cookstoves typically found in Peruvian communities.

Modeling Vocal Fold Intravascular Flow With Synthetic Replicas, Aaron David Terry

Theses and Dissertations

Communication by voice is foundational in our society and many rely on their voices for their occupations. Voice disorders affect a significant number of individuals each year, and diagnosis and treatment improvements are therefore sought via advancements in voice research. Contained in this thesis is a description of work intended to contribute to vocal fold research by using synthetic, self-oscillating vocal fold replicas to study the impact of replica vibration on perfusion fluid flow through the replica. Methods for manufacturing vocal fold replicas containing imbedded channels allowing for fluid perfusion are discussed. Experimental procedures developed for delivering perfusion fluid to …

Thermal Transport At Superhydrophobic Surfaces In Impinging Liquid Jets, Natural Convection, And Pool Boiling, Matthew Clark Searle

Theses and Dissertations

This dissertation focuses on the effects of superhydrophobic (SHPo) surfaces on thermal transport. The work is divided into two main categories: thermal transport without phase change and thermal transport with phase change. Thermal transport without phase change is the topic of four stand-alone chapters. Three address jet impingement at SHPo surfaces and the fourth considers natural convection at a vertical, SHPo wall. Thermal transport with phase change is the topic of a single stand-alone chapter exploring pool boiling at SHPo surfaces. Two chapters examining jet impingement present analytical models for thermal transport; one considered an isothermal wall and the other …

Visual Servoing For Multirotor Precision Landing In Varying Light Conditions, Jesse Wynn, Tim Mclain

Faculty Publications

The problem of performing a precision landing of an autonomous multirotor UAV in various lighting conditions is studied. A vision-based approach is proposed and consists of varying degree-of-freedom image-based visual servoing (VDOF-IBVS), and a specialized landing marker. The proposed approach is validated through extensive flight testing outdoors in both lighted and dark conditions, and is done using a standard off-the-shelf autopilot system.

Developable Compliant-Aided Rolling-Contact Mechanisms, Todd G. Nelson, Just L. Herder

Student Works

Rolling-contact mechanisms can provide low-friction motion with unique kinematic paths. We show that developable surfaces can be used as a design tool for rolling-contact mechanisms joined with compliant bands. These mechanisms can exhibit 3D motion paths, couple rotational and translational motions into a single degree of freedom, and can be designed to exhibit various tailored kinetic responses. We set forth developable surface parametrizations well suited to the creation of rolling contacts. We highlight how the geodesic and principal curvatures of the non-ruling principal curves of a developable surface are meaningful design quantities for rolling contacts. We provide kinematic and kinetic …

Total Hemispherical Apparent Radiative Properties Of The Infinite V-Groove With Diffuse Reflection, Rydge B. Mulford, Nathan S. Collins, Michael S. Farnsworth, Matthew R. Jones, Brian D. Iverson

Faculty Publications

DYNAMIC control of radiative surface properties enables optimization of thermal management systems for spacecraft, radiative cooling systems, and other applications [1–3]. Various methods of altering the absorption or emission from a surface have been investigated [4–6]. Use of origami-inspired tessellated surfaces to control apparent radiative surface properties is a promising technology [7–9]. Realizing the full potential of tessellated surfaces to dynamically control apparent radiative surface properties requires convenient methods of calculating apparent properties as a function of tessellation geometry and intrinsic radiative surface properties. This Note focuses on the use of geometry to affect total, hemispherical properties of V grooves …