Engineering Commons^™

Modular Cable - Driven Surgical Robots, Carl A. Nelson, Nicholas Nelson

Department of Mechanical and Materials Engineering: Faculty Publications

A surgical robot can be configured for minimally invasive surgery ( MIS ) and other types of surgery with modular link geometry and disposable components. In some examples, the surgical robot includes a cable driver comprising at least one drive motor configured for tensioning a cable. The surgical robot includes an articulated surgical tool coupled to the drive motor by the cable. The articulated surgical tool comprises at least first and second articulated links and a joint coupling the first and second articulated links. The cable passes through the joint, and the joint comprises an elastic antagonist biased in opposition …

Gross Positioning Device And Related Systems And Methods, Mark A. Reichenbach, Shane M. Farritor

Department of Mechanical and Materials Engineering: Faculty Publications

Disclosed herein are gross positioning systems for use with robotic surgical devices to provide gross positioning of the robotic surgical devices. The gross positioning systems have a base, a first arm link operably coupled to the base, a second arm link operably coupled to the first arm link, a third arm link operably coupled to the second arm link, and a slidable coupling component slidably coupled to the third arm link.

Mono Ski Trainer, Alexander Scott Hinerman, Shayla Anne Schoensee, Carson Rinkenberger, Barrett L. Osborne

Mechanical Engineering

The intent of this Final Design Report document is to provide the final design of a mechanical engineering senior project to our client and user Ethan Scott. The aforementioned project is a mono ski at-home trainer carried out by a group of students attending California Polytechnic State University, San Luis Obispo over one academic year. This document contains the previously shared reports Statement of Work (SOW), Preliminary Design Review (PDR), and Critical Design Review (CDR) that provide background and details of our team’s design process to reach our final design. The as-built design and evaluation is described in the Final …

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 …

Interactive Lego Girl Scout Arm, Chris Suzuki, Emi Okuyama, Bryson Shores, Karina Sandoval

Mechanical Engineering

This Senior Project Report document outlines the senior design project for Girl Scouts of California’s Central Coast (GSCCC) led by a team of four Mechanical Engineering students at California Polytechnic State University, San Luis Obispo. The project encompasses the researching, designing, prototyping, and testing of a LEGO robotic arm for the Girl Scouts to learn more about STEM (Science, Technology, Engineering, and Mathematics) and provide support to each Girl Scouts cookie sales in their stores. Their goal was to build a LEGO robotic arm that will interact with customers at the Girl Scout stores and promote the girl scouts' interest …

Galilean Cannon, Mariah Kirkham, Marcus Beloney, Jonas Honeyman, Joshua Pratt

Mechanical Engineering

This comprehensive report details our team’s senior capstone design project, which involved the design, construction, and installation of a Galilean Cannon exhibit—a linear momentum experiment involving rebounding balls—for the San Luis Obispo Children’s Museum.

This report is split into four parts, as follows. Part One describes the needs of our sponsor and target market, as well as background research on the concept. Part Two details the ideation, decision making, and proofing process leading to our Preliminary Design concept. Part Three discusses the preliminary analysis and plans for the final prototype. Part Four describes construction and testing of the operational exhibit …

Tholos - Eva Sample Location Calibration Device, James Verheyden, Kat Gipson, Julia Rios, Ben Trust

Mechanical Engineering

To support NASA’s upcoming Artemis missions, an extravehicular activity (EVA) photometric calibration scale was developed to replace the Apollo-era Gnomon device. The Gnomon was a gimbaled stadia rod mounted on a tripod which provided color and reflectivity photo calibration, vertical orientation, and solar shadow direction, to include in photos of lunar geologic samples and features. With over 50 years of innovation since the first Gnomon deployment on Apollo 11, this redesign of the photometric calibration scale will support NASA’s missions in the modern day. The Tholos™, named after the ancient Greek repository of standardized measures, consists of a quadrupedal design …

Demonstration Triple Spool Turbine And Controls, Synnovea Alaina Wood, Marco Eston Salguero, Michael Bruce Megna, Wyatt Scott Conner

Mechanical Engineering

The demonstration triple-spool turbine and controls project consisted of the conceptualization, design, analysis, build, and test of a demonstration model of three concentric driveshafts, such as those used in conventional turbofan (or power generation turbine) engines. Specifically, our team focused on building a basic, portable, mechanical model of such a driveshaft assembly, while also developing the backend firmware/control and user interface software used to control it. This model was developed with the initial intent of use in the Cal Poly engines lab with a goal of remotely controlling the motors driving the driveshaft model by means of a USB cable …

Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter

Materials Engineering

Polymer concrete is a composite material used to replace cast iron and steel in wafer grinding machines for vibration damping. During the grinding and lapping processes of manufacturing silicon wafers, excessive vibrations may cause subsurface damage which requires additional polishing and reduces yield. Nine compositions containing various levels of granulated rubber and glass fibers were manufactured. CRM WRF-10 granulated rubber was examined at 0%, 5%, and 10% and Corning Cem-Fil glass fibers were added at 0%, 0.5%, and 1% by weight. Smooth-On EpoxAcast 690 epoxy resin was held constant at 16% for each composition. Crushed granite aggregate from Martin Marietta, …

Heating Lanyard To Warm Body Core, Cole Bunker, Spencer Alonge, Tyler Elsom, Matthew Hyland

Mechanical Engineering

Calculated Industries, a company that specializes in construction products headquartered in Carson City, Nevada, has sponsored the Heating Lanyard to Warm Body Core senior project. The objective of the project was to design and manufacture a body core heating device that will be used by construction workers to keep warm in cold environments. The goal is to create a device that is safe, comfortable, and temperature controllable. Our team consists of four mechanical engineering students at California Polytechnic State University, San Luis Obispo. Research was performed to analyze current products in the market, analyze how to best provide heat to …

Shallow-Water Wind Turbine Foundation, Andrew Walker, Nico Nani, James Cusanelli, Zachary Dunkelberger

Mechanical Engineering

Over the 2021-2022 academic year, we, the Shallow Water Wind Turbine Foundation senior project team, designed, manufactured, and tested a fixed bottom, sand mounted turbine foundation for the Cal Poly Wind Power Club’s Collegiate Wind Competition turbine. The foundation was restricted to certain material, installation, and geometric constraints outlined in this report, and needed to support the turbine under operating conditions including 22 m/s wind speeds. The design was analyzed using primarily a bearing capacity geotechnical analysis to determine final geometry and weight. The foundation was then manufactured using welded, custom carbon steel parts.

The foundation was inspected for geometric …

Development Of A Body Weight Reduction Algorithm In Micro-Gravity Treadmills™, Alexander Hibbert

Master's Theses

Boost Treadmills™, a company specializing in the use of differential air-pressure (DAP) technology in the realm of exercise and rehabilitation, is developing their second-generation micro-gravity treadmill™ named the Boost 2. This machine will allow individuals in all types of fitness environments to move and exercise at a fraction of their normal body weight, reducing the impact forces on lower body extremities and allowing for accelerated returns to activity.

The purpose of this thesis was to create an algorithm to be implemented on the Boost 2 that related the percentage of body weight reduction of a user to a required pressure …

Monolithic Integration Of Hybrid Perovskite Single Crystals With Silicon For Highly Sensitive X - Ray Detectors, Jinsong Huang, Wei Wei

Department of Mechanical and Materials Engineering: Faculty Publications

Perovskite single crystal X - ray radiation detector devices including an X - ray wavelength - responsive active layer including an organolead trihalide perovskite single crystal, a substrate layer comprising an oxide, and a binding layer disposed between the active layer and the substrate layer. The binding layer including a binding molecule having a first functional group that bonds to the organolead trihalide perovskite single crystal and a second functional bonds with the oxide. Inclusion of the binding layer advantageously reduces device noise while retaining signal intensity.

Passivation Of Defects In Perovskite Materials For Improved Solar Cell Efficiency And Stability, Jinsong Huang, Xiaopeng Zheng

Department of Mechanical and Materials Engineering: Faculty Publications

Semiconductor devices , and methods of forming the same , include a cathode layer , an anode layer , and an active layer disposed between the cathode layer and the anode layer , wherein the active layer includes a perovskite layer . A passivation layer is disposed directly on a surface of the active layer between the cathode layer and the active layer , the passivation layer including a layer of material that passivates both cationic and anionic defects in the surface of the active layer .

Assessment Of Mechanical Engineering Skills: A Synthesis Of Industry And Academic Graduate Level Curriculum Requirements, Francie Baker

Theses and Dissertations

Students who graduate with an advanced degree in mechanical engineering are a diverse group in their path to post-baccalaureate degree attainment. Some students choose to obtain their master’s or Ph.D. post bachelors, but before they enter the workplace. Others enter the workforce and return as full-time students or progress on their advanced degrees while maintaining part- or full-time employment. Current accreditation standards for undergraduate degree programs are part of a changing landscape of standards and professional requirements that have adapted and continue to adapt as programs prepare students to work in professional engineering fields. Advanced degrees do not have the …

Design, Construction, And Characterization Of A Test Stand Used To Test Filter Media, Adam W. Parsons

Theses and Dissertations

Air filters are routinely used to remove various aerosols ranging from radioactive particles to airborne viruses. The overall performance of a filter may be simplified to consider only two main performance characteristics: 1) the efficiency at which particles are removed by the filter, and 2) the filter’s resistance to air flow. Per the DOE Nuclear Air Cleaning Handbook, HEPA filters require a minimum filter efficiency of 99.97% for particles 0.3 micrometers in diameter. Understanding how filters will perform with respect to time and mass loading is essential towards building more robust filters that operate more efficiently and safely. Analyzing the …

Challenges And Signal Processing Of High Strain Rate Mechanical Testing, Barae Lamdini

Theses and Dissertations

Dynamic testing provides valuable insight into the behavior of materials undergoing fast deformation. During Split-Hopkinson Pressure Bar testing, stress waves are measured using strain gauges as voltage variations that are usually very small. Therefore, an amplifier is required to amplify the data and analyze it. One of the few available amplifiers designed for this purpose is provided by Vishay Micro-Measurements which limits the user’s options when it comes to research or industry. Among the challenges of implementing the Hopkinson technology in the industry are the size and cost of the amplifier. In this work, we propose a novel design of …

Investigating Polynominal-Fit Extrapolation For Iterative Gain Updating In A Controller, Malachi Landis

Honors Capstone Projects and Theses

No abstract provided.

Enhancing Stability Of High-Nickel Cathodes For Lithium-Ion Batteries Through Additive Manufacturing Of Cathode Structure, Matthew Sullivan

Mechanical Engineering Undergraduate Honors Theses

Lithium-ion batteries (LIBs) are currently the best method to store electrical energy for use in portable electronics and electronic vehicles. New cathode materials for LIBs are consistently studied and researched, but few are as promising and attainable as nickel-rich transition metal oxides such as LiNi1-x-yMnxCoyO2 (NMC). NMC materials exist with many different mass ratios, but higher nickel content materials provide higher energy density. With this increase in capacity comes a sacrifice with cyclability, as high-nickel NMC variants are prone to structure collapse, transition metal dissolution, and cracks due to volume change. In this report, mechanical modification of the electrode by …

Examining The Different Snap-Through Characteristics Of Bistable Cfrp Composite Laminates, Vishrut Deshpande

All Theses

Bistable carbon fiber composites, whose bistability arises from having asymmetric fiber layouts in different layers, have shown immense potential for use in shape morphing and adaptive structure applications. While many studies in this field focus on these composite laminates’ external shapes at the two stable states, their snap-through behavior of shifting from one stable shape to the other remains a critical aspect to be investigated in complete detail. Moreover, symmetric loading conditions have been extensively studied based on the classical lamination theory, but the asymmetric loading conditions received far less attention. Therefore, this study examines an asymmetric, localized point load …

Strain-Based Design Of Steel-Polymer-Steel Composite Pipes, Vul Thang

LSU New Orleans Theses and Dissertations

Many offshore single-wall pipelines and structural failures have occurred in the past. As a result, lives were lost, and billions of dollars were spent. In addition, natural disasters such as earthquake fault zones can cause a large volume of soil movement. This can easily damage single-wall pipelines or piles of fixed offshore platforms in the earthquake fault zone.

Currently, the single-wall pipelines are used for the offshore and onshore oil and gas industry. This research investigated the use of double-wall composite pipe steel-polymer-steel (SPS) in place of single-wall pipe to prevent such failures. The double-wall composite pipe has a larger …

Cal Poly Fluid Power Vehicle Challenge 2022, Sangmin Sung, Eddy Rodriguez, Travis Welch, Jeremy Baechler, Kevin Pauls

Mechanical Engineering

In this report, the Featherweight Cycles design team puts forth the scope and overview of their design project, discusses background research and competitor analysis, and presents the project’s final design and manufacturing plans. The overall goal of this project is to fabricate and compete in the Fluid Power Vehicle Challenge, hosted by the National Fluid Power Association. To better define the design process, the team researched previous year’s designs from Cal Poly, as well as winning designs from the last two years to form a baseline of knowledge about competing schools’ designs. After researching multiple design paths, Featherweight Cycles chose …

Fluid Structure Interactions Within A Common Rail Diesel Injector., Russell Prater

Electronic Theses and Dissertations

The internal flow of a high-pressure diesel injector is simulated numerically to investigate the complex transient flow structures and the unsteady forces imparted to the injector needle that result from the asymmetric flow fields developed during operation. The gas-liquid two phase flow is simulated using a mixture model with the cavitation numerically modeled using the Zwart-Gerber-Belamri model. Both the k-ε model and the detached eddy simulation (DES) model are used, and the numerical results are compared. This dissertation looks at the internal flow of a generic injector at different lifts and characterizes the flow parameters at high lift and low …

Predictive Performance And Teaming Via The Mist-C Ocean Hierarchy Utilizing Personality And Skills, Brighton H. Owen

All Theses

This thesis seeks to establish and define the individual, the team as an entity, and qualify various metrics to predict team performance. When several individuals come together, they form a team that is often capable of designing and developing concepts beyond the individual on their own by methods of task dispersion, goal orientation, communication, and more. With these teams comes growth and increased performance leading to more efficient processes and better metrics by which performance may be measured. To achieve this, 34 engineering students in the AerosPACE senior design program, which lasted two semesters, were asked to complete surveys in …

Analysis Of The Self-Heating Effect On Unfilled Poly(Methyl Methacrylate) Due To Cyclic Behavior, Muhammed R. Kose

All Theses

Poly(methyl methacrylate, (PMMA) has been implemented as part of the supporting structure in complete hip and knee replacements since the 1950s. Known as bone cement while in the body, PMMA is known to undergo compressive and tensile stresses that wear down the bio-compatible barrier and cause pieces to come loose inside the human body. These pieces are then attacked by the body’s own nervous system, leading to inflammation, and eventually necessitating replacement. It has been documented that under cyclic loading PMMA can reach temperatures that start to degrade its tensile capabilities. In this study the potential cause of self-heating was …

Investigating The Effects Of Topology On The Fracture And Failure Mechanisms Of Low Density Metamaterials, Kaitlynn Melissa Conway

All Dissertations

Advances in additive manufacturing have enabled the creation of low density metamaterials with fine features and complex topographies. These new metamaterial topologies and size scales not previously possible broaden the spectrum of lightweight materials with unique properties that are advantageous in a variety of applications. There however is a lack of understanding of metamaterial failure and fracture behaviors. Studies tend to report only a few material properties rather than a comprehensive description of behavior. Due to this, there is a hesitancy to incorporate metamaterials into engineering designs despite proven remarkable properties. This work seeks to investigate in three parts the …

Characterization Of Friction Element Welding Using Finite Element Modeling, Ankit Varma

All Dissertations

Friction element welding (FEW) has been advocated as a solution to weld different materials together, with the ability to join high-strength materials for a range of thicknesses with low input energy and a short processing time. This work develops a coupled thermal-mechanical finite element model to better understand the physical mechanisms involved in the process and to predict temperature and material flow during the process. Furthermore, microstructural analysis is performed for the steel layer using a scanning electron microscope and Vickers microhardness tester to understand the variation in its grain structure and hardness. Results from the finite element model and …

Inertially Stabilized Gimbal, Miranda Grace Bilbrey

Honors Capstone Projects and Theses

No abstract provided.

A Molecular Dynamics Study Of The Laser Sintering Process And Subsequent Mechanical Properties Of Γ-Tial Nanoparticles, Eleanor Dickens

Honors Theses

Using molecular dynamics (MD) simulations, the laser sintering additive manufacturing process is investigated through the observation of γ-TiAl nanoparticles. This process is conducted using both uni-directional chain and stacking configurations. By mimicking the heating process and varying laser sintering parameters such as heating rater, sintering temperature, and particle orientation, the fusion behavior and resulting products are analyzed for both chain and stacking NP patterns. In of single chain cases, it is noticed that slower heating rates and higher melting temperatures yield larger neck growth between each individual particle and thus produce a more stable product. This leads to stronger mechanical …

Effects Of Varied Oxygen Levels, Laser Powers, And Scanning Speeds On Manufactured Components By Laser-Based Powder Bed Fusion, Amelia Mcnamee

Honors College Theses

This project addresses the effects of oxygen concentration, laser power, and scanning speed on the melt pool geometry of laser-based powder bed fusion (L-PBF) additively manufactured components. A parametric analysis using the substrate alone was conducted to determine a range of desirable laser powers and scanning speeds. The parameter with the more significant effect will be decided upon based on the depth-to-width ratios (D/W) of the resultant laser weld bead. A range of oxygen levels and scan speeds was selected for the next phase. These samples were then be analyzed for depth-to-width ratios. It was expected that higher oxygen concentrations …