Manufacturing Commons^™

Bioprinting With Human Stem Cell-Laden Alginate-Gelatin Bioink And Bioactive Glass For Tissue Engineering, Krishna C. R. Kolan, Julie A. Semon, Bradley Bromet, D. E. Day, Ming-Chuan Leu

Biological Sciences Faculty Research & Creative Works

Three-dimensional (3D) bioprinting technologies have shown great potential in the fabrication of 3D models for different human tissues. Stem cells are an attractive cell source in tissue engineering as they can be directed by material and environmental cues to differentiate into multiple cell types for tissue repair and regeneration. In this study, we investigate the viability of human adipose-derived mesenchymal stem cells (ASCs) in alginate-gelatin (Alg-Gel) hydrogel bioprinted with or without bioactive glass. Highly angiogenic borate bioactive glass (13-93B3) in 50 wt% is added to polycaprolactone (PCL) to fabricate scaffolds using a solvent-based extrusion 3D bioprinting technique. The fabricated scaffolds …

Zinc Ferrite Based Gas Sensors: A Review, Kaidi Wu, Jianzhi Li, Chao Zhang

Manufacturing & Industrial Engineering Faculty Publications

Flammable, explosive and toxic gases, such as hydrogen, hydrogen sulfide and volatile organic compounds vapor, are major threats to the ecological environment safety and human health. Among the available technologies, gas sensing is a vital component, and has been widely studied in literature for early detection and warning. As a metal oxide semiconductor, zinc ferrite (ZnFe2O4) represents a kind of promising gas sensing material with a spinel structure, which also shows a fine gas sensing performance to reducing gases. Due to its great potentials and widespread applications, this article is intended to provide a review on the latest development in …

Micro-Ct Evaluation Of Defects In Ti-6al-4v Parts Fabricated By Metal Additive Manufacturing, Haijun Gong, Venkata Karthik Nadimpalli, Khalid Rafi, Thomas Starr, Brent Stucker

Manufacturing Engineering: Faculty Publications (2015-2023)

In this study, micro-computed tomography (CT) is utilized to detect defects of Ti-6Al-4V specimens fabricated by selective laser melting (SLM) and electron beam melting (EBM), which are two popular metal additive manufacturing methods. SLM and EBM specimens were fabricated with random defects at a specific porosity. The capability of micro-CT to evaluate inclusion defects in the SLM and EBM specimens is discussed. The porosity of EBM specimens was analyzed through image processing of CT single slices. An empirical method is also proposed to estimate the porosity of reconstructed models of the CT scan.

Cisco Nexus 9200 Robustness Redesign, Colin Berge, Ethan Gold, Cole Christopherson, Rahul Makhijani

Industrial and Manufacturing Engineering

Certain configurations of Cisco's Nexus 9200 product experienced issues with bending during shipping. Two solutions were developed to eliminate this problem: an external brace that could quickly address the problem yet was expensive and unsustainable, and a redesigned chassis, which was more economical but came with a longer time to implement. Real world packaging and shipping conditions were simulated in SolidWorks and Finite Element Analysis was used to model the stresses experienced when the product is dropped. Both designs were found to significantly reduce stress in critical areas, thus reducing the chance of failure and the cost of the problem. …

Fluid Power Vehicle Challenge - The Incompressibles - Final Design Report, Nicholas Gholdoian, Russell Posin, David Vitt, Alex Knickerbocker, Kyle Franck, Julian Rodkiewicz

Mechanical Engineering

This report provides a comprehensive description of the research, analysis and design work that The Incompressibles have completed thus far in the senior project process. This document includes all the work that The Incompressibles have completed for the team’s Preliminary Design Review (PDR), Critical Design Review (CDR), the work leading up to the 2019 FPVC competiton and the competition results. This report includes the initial research that the team completed for the fluid power competition, first iterations of designs, final iterations of designs, manufacturing results and processes, and finally testing and results from competition. With a new design for the …

Insulated Solar Electric Cooker Immersion Heater, Emily Burnside, Kaeley Dicks, Joshua R. Stevens, Brady Banks

Mechanical Engineering

This report is the final design review (FDR) report for our team completing the Insulated Solar Electric Cooker (ISEC) Immersion Heater mechanical engineering senior project. The goal of this project is to standardize and perform analysis on a preexisting, inexpensive solar-powered immersion heater for cooking use in developing countries, reducing the adverse effects presented by traditional biomass cooking fires. We also designed a manufacturing process to improve repeatability and to reduce labor investment of heater production. The ISEC research team from the California Polytechnic State University Physics Department have been working on the development of this immersion heater and have …

Redesign Of Cubesat For Beam Charging, Kuba Preis

Industrial and Manufacturing Engineering

This paper is intended to be a study in the applications of the design freedom granted by additive manufacture in the design of a 1U CubeSat frame. The main loads experienced by a CubeSat are structural (during launch) and thermal (solar radiation). Beam charging is an emerging technology which involves charging a CubeSat using a laser beam. In this paper, a CubeSat frame was redesigned to account for the structural loads induced during launch and the thermal loads induced when beam charging. The thermal, weight, design, and structural requirements for a new CubeSat design were derived. The 1U CubeSat frame …

Human Powered Vehicle Trainer, Nicholas Hung Nguyen, Gregory Reece Bridges, Jacinta Garcia, Mitchell Sidney Smith

Mechanical Engineering

This Final Design Review (FDR) document describes the final design and completed prototype of a Mechanical Engineering senior project team at California Polytechnic State University, San Luis Obispo. The project goal is to create an adjustable human powered vehicle training bike for George Leone that allows a rider to gain confidence with the unique reclined bike geometry ahead of the World Human Powered Speed Challenge at Battle Mountain, Nevada. This document outlines the customer’s needs and technical research performed which together determine the project’s scope and engineering specifications. Next, we present the initial idea generation process and its results, along …

C6 Wheels, Samuel L. Pizot, Luke Martin, Josh Warner, Jonah Levis

Mechanical Engineering

This document details the C6 Wheels project being undertaken for senior design. The objective is to design and manufacture carbon fiber reinforced polymer wheels for the Cal Poly Formula Society of Automotive Engineers (FSAE) team. The wheel shells will be used on FSAE’s competition vehicles. FSAE requested the wheels to improve the handling characteristics of their vehicles by reducing the unsprung and rotational mass. They have attempted carbon fiber wheels previously but have not yet run any on their vehicles. FSAE specifically proposed the design of carbon fiber shells with an aluminum center as opposed to full carbon fiber wheels …

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

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 …

Adapted Trailer Hitching System, Joseph Neil Hearn, Maxwell M. Selna, Maximilian D. Cossalter, Eric B. Ringsrud

Mechanical Engineering

This report highlights the entire design process of an adapted trailer hitching system for Taylor Morris: a navy veteran and quadruple amputee. This begins with problem definition through customer and product research. Objectives are generated after the problem is defined and the boundary of the project is set. This outcome of the project focuses on modifications/improvements to the vehicle side of the problem and leaves the trailers untouched. Engineering specifications are developed to constrain the concept design direction, which ultimately dictates the outcome of the final design. The final design is used as a basis to manufacture a structural prototype …

Modifying Casting Parameters To Improve The High Temperature Ductility Of Investment Cast Nickel-Based Superalloy Pwa 1455, Lars Alexander Hedin, Cole Magnum Introligator

Materials Engineering

PCC Structurals, an industry leader in superalloy investment castings, has observed inconsistencies in the stress rupture performance of polycrystalline nickel-based superalloy PWA 1455. PCC has changed their casting parameters to reduce the thermal gradient during cooling but have been unable to correlate these changes with an increase in stress rupture elongation. Metallographic examination of past samples indicated microstructures composed of non- equiaxed dendritic grains with mean diameter of .021 inches along the test axis. A similar study on polycrystalline superalloys has indicated that excessive superheat temperatures above the liquidus can result in large grains identical to those observed, limiting the …

Sand Foot: A Prosthesis For Walking On Sand, Samantha A. Galicinao, John Dewing, Daniel Dugan Dotson, Christopher Urasaki

Biomedical Engineering

This critical design report describes the product development of a prosthesis for use on sand. Quality of Life Plus (QL+), a national non-profit organization aimed to develop prostheses for veterans and people with disabilities, introduced this project and its accompanying challenger, Sgt. Brady, to Cal Poly’s Interdisciplinary Senior Project class in September 2018. After consulting with Sgt. Brady and QL+ and performing extensive research, the Sand Foot team defined customer requirements and engineering specifications to meet these requirements. Comfortability, durability, and sandproof were key customer requirements. Several conceptual models were brainstormed and a final design was selected based on the …

Bulk-Explosion-Induced Metal Spattering During Laser Processing, Cang Zhao, Qilin Guo, Xuxiao Li, Niranjan Parab, Kamel Fezzaa, Wenda Tan, Lianyi Chen, Tao Sun

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Spattering has been a problem in metal processing involving high-power lasers, like laser welding, machining, and recently, additive manufacturing. Limited by the capabilities of in situ diagnostic techniques, typically imaging with visible light or laboratory x-ray sources, a comprehensive understanding of the laser-spattering phenomenon, particularly the extremely fast spatters, has not been achieved yet. Here, using MHz single-pulse synchrotron-x-ray imaging, we probe the spattering behavior of Ti-6Al-4V with micrometer spatial resolution and subnanosecond temporal resolution. Combining direct experimental observations, quantitative image analysis, as well as numerical simulations, our study unravels a novel mechanism of laser spattering: The bulk explosion of …

Design And Control Of Fiber Encapsulation Additive Manufacturing, Matt Saari

Mechanical Engineering Research Theses and Dissertations

This work presents the design, development, and analysis of the Fiber Encapsulation Additive Manufacturing (FEAM) system developed at the Laboratory for Additive Manufacturing Robotics \& Automation at the Lyle School of Engineering at Southern Methodist University. The innovation introduced by FEAM is the ability to insert a continuous fiber of different material into the flowing extrudate. Correctly positioning the fiber feed inside the extrudate while turning the fiber in arbitrary directions is a critical aspect of the technology. This will allow for the full exploitation of the capabilities of the FEAM technology to produce robotic components that actuate and sense. …

Repurposing Plastic Waste In El Cercado, Joseph Dooling, Kirby Townsend, Brendan Smith

Honors Thesis

This project aims to assist the community of El Cercado in the Dominican Republic in turning their plastic waste into useful products. The design team developed a first iteration shredder, injector, and aluminum mold which future design teams could further iterate in order to make products out of waste plastic. Different products were researched to ensure that they can be sold or used in the community. The goal of producing these items is to stimulate economic activity in the community by creating economic opportunity. The design shall also be sustainable in three ways. It shall reuse plastic waste while also …

Problem Based Learning: A Case Study From Mechanical Engineering, Kevin Delaney, Ger Nagle

Conference papers

Engineering graduates today must be capable of much more than solving technical problems taught in engineering school. Despite learning to quantify the performance of certain engineering objects, undergraduate students find it challenging to integrate these elements into basic design concepts through a coherent and systematic design process. To help students develop real-world engineering skills as part of their engineering education, the Mechanical Engineering Discipline in Technological University Dublin (TU Dublin) introduced Problem Based Learning (PBL) for Third Year Mechanical Engineering students in 2005.

A recent review of this teaching approach highlighted deficiencies not envisaged when the initial PBL module was …

Fault Adaptive Workload Allocation For Complex Manufacturing Systems, Charlie B. Destefano

Graduate Theses and Dissertations

This research proposes novel fault adaptive workload allocation (FAWA) strategies for the health management of complex manufacturing systems. The primary goal of these strategies is to minimize maintenance costs and maximize production by strategically controlling when and where failures occur through condition-based workload allocation.

For complex systems that are capable of performing tasks a variety of different ways, such as an industrial robot arm that can move between locations using different joint angle configurations and path trajectories, each option, i.e. mission plan, will result in different degradation rates and life-expectancies. Consequently, this can make it difficult to predict when a …

Design Of A Scara Based Mobile 3d Printing Platform, Zachary Hyden

Mechanical Engineering Undergraduate Honors Theses

Currently 3D printers rely heavily on people to run them, there is no automatic way to start a new print after one has finished. On top of this 3D printers are limited in the area they can print on. Even though the additive manufacturing market is rapidly growing and is increasingly being used in product manufacturing there has yet to be a solution to this problem. This research proposes using mobile 3D printing robots to solve both of these issues. The proposed prototype utilizes a Selective Compliance Assembly Robot Arm (SCARA) based robot capable of cooperatively manufacturing parts. This allows …

Framed Human Powered Vehicle Frame, Keyanna Brielle Henderson, Brendon Howard Morey, Kyra Noelle Schmidt, Austin Patrick Henry

Mechanical Engineering

The following is the Final Design Review (FDR) Report for Framed, a team tasked with designing and fabricating the frame of the 2018-2019 Cal Poly Human Powered Vehicle (HPV) Club bike. The bike is to be raced at the 2019 World Human Powered Speed Challenge in Battle Mountain, Nevada with the goal of breaking the American collegiate speed record. The purpose of the FDR Report is to introduce the project’s background and objectives, discuss the final design, and present the results of manufacturing and testing. Prior to beginning work on the design of the frame, the group conducted extensive research …

Vaccine Cooler For The Global Poor, Benjamin J. Larson, Cooper E. Gibson, Eilbron Younan, Cody R. Volk

Mechanical Engineering

Cal Poly physics professors Peter Schwartz and Nathan Heston approached the Solar Freeze team with the problem that remote communities in Africa have limited access to modern-day medicine or vaccines. They suggested that we try and design a cooling device that can keep vaccines cold for multiple days at a time while the medicine is transported to remote villages. Currently, there are vaccine cooler products on the market, but most of them are very expensive or lack portability. Peter and Nate have tasked the Solar Freeze team to come up with a less expensive solution that is also portable and …

Final Design Report For Human Powered Vehicle Drivetrain Project, Derek Fromm, Luke Opitz, Michael Juri, Olivier Côté

Mechanical Engineering

The Cal Poly Human Powered Vehicle Club is building a bike to surpass 61.3 mph in 2019. The club and their mentor, George Leone, have proposed a senior project to design, build, and test the drivetrain for this year’s human powered vehicle. Research into human powered vehicles and their drivetrains has shown that the power that a rider can output and the efficiency at which the rider can pedal depend extensively on the design of the drivetrain. Despite the existence of standard bicycle drivetrain designs, the senior project team has found that the best design to meet the club’s requirements …

Development Of A Multi-Probe Kelvin Scanner Device For Industrially-Relevant Characterization Of Surface-Activated Carbon Fiber Reinforced Thermoplastic Composites, Kirby Simon

McKelvey School of Engineering Graduate Student Theses & Dissertations

Carbon fiber reinforced thermoplastic (CFRTP) composites are becoming increasingly attractive materials in manufacturing due to their lightweight nature, mechanical strength, and corrosion resistance. Surface activation of these materials is usually required during processing to increase the bond strength of assemblies (aerospace and automotive industries) or improve adhesion with implants (biomedical industry). Industrially-relevant, nondestructive quality control methods for assessing the activation state of these materials do not currently exist, however. Applying principles discovered through the use of scanning probe microscopy, a multiple-probe Kelvin scanning (MPKS) device has been developed that can assess the uniformity of the activation state of plasma-treated CFRTP …

Danny’S Recumbent Bike Accessibility Device Final Design Report, Joseph J. Lee, Huy Nguyen, Jack Mcatee, John Kulick

Mechanical Engineering

The purpose of this document is to fully define our design solution and explain our manufacturing and testing results. Our project’s goal is to find a way to allow Danny Knutson, a retired Navy pilot and incomplete quadriplegic with limited use of his arms and an impaired sense of balance, to enter and exit his recumbent tricycle without any discomfort for him or his aide. We completed multiple interviews with Danny, patent research, existing product research, and other technical literature research in order to fully understand the problem. We synthesized this information to create a concrete list of customer wants …

High Strollers, Braeden Hammond, Morley Perrin, Reid Bartels, Juan Rodriguez

Mechanical Engineering

This report documents the final product of Jonathon’s new lightweight stroller. The Mechanical Engineering team from Cal Poly, High Strollers, began the project to create a lightweight stroller for the project sponsor, Nina Aguayo, and her son, Jonathon Aguayo, in Fall of 2018. Jonathon is diagnosed with Delayed Brain Development and Hypotonia with some characteristics of Cerebral Palsy. He has a 50lb high intensity stroller to go to and from school. Mrs. Aguayo needed a stroller that is easier to transport while still meeting all of Jonathon’s needs. The re-designed stroller will make leisurely outings for Mrs. Aguayo and Jonathon …

Universal Bike Suspension Design, Ernesto Huerta, Gregory Ryan Ritter, Chris Michael Fedor, Michael Wu

Mechanical Engineering

Cal Poly Bike Builders (CPBB) is a student club at Cal Poly helping students design and fabricate their own bicycles. Currently, club members build rigid frames and mountain bikes with only front-suspension–commonly referred to as a “hardtail”. As more students join the club, interest grows in building full-suspension mountain bikes (FSMTB). Designing and manufacturing a mountain bike rear-suspension system requires a diverse skillset and a substantial time commitment. As a result, individual efforts building FSMTB have proven unsuccessful. The scope of this project is to develop a defined method and necessary tools such that all CPBB members can efficiently build …

Additive Manufacturing Of High Performance Flexible Thermoelectric Generators Using Nanoparticle Inks, Tony Valayil Varghese

Boise State University Theses and Dissertations

Flexible thermoelectric devices are attractive power sources for the growing demand of flexible electronics and sensors. Thermoelectric generators have an advantage due to no moving parts, silent operation and constant power production with a thermal gradient.

Conventional thermoelectric devices are rigid and fabricated using complex and relatively costly manufacturing processes, presenting a barrier to increase the market share of this technology. To overcome such barriers, this work focuses on developing near ambient-temperature flexible thermoelectric generators using relatively low-cost additive manufacturing processes. A screen printable ink was developed for transforming nanoparticle ink into high-performance flexible thermoelectric generators with a peak thermoelectric …

Design Of A Bedside Walker-Cane Hybrid To Aid Senior Adults Avoid Falls During Night Walks, Jorge L. Gutierrez

Theses and Dissertations

The objective of this research and development work is to design a device to help senior adults prevent fall during night walks indoors. The problem of elders falling at a night setting was found to be caused by the multiple environmental and medical conditions. The target demographic was found to be seniors from age 65 and older. Several occupational therapists and two physical therapists were consulted to gain knowledge on elders' behavior, possible improvements on current existing devices, and feedback regarding the early prototype built. Several products and patents were researched with a lack of findings on similar products that …

Blockchain Technology Based Supply Chain Systems And Supply Chain Performance: A Resource-Based View, Madhavi Latha Nandi

Theses and Dissertations

Blockchain technology (BCT) is set to transform firms’ present ways of managing supply chains. This thesis explores how the efforts by firms to integrate BCT into their supply chain systems and activities, can enable certain supply chain capabilities and subsequently, improve supply chain performance. Using an abductive research approach, qualitative content analyses of 126 cases of firms’ efforts in BCT-based supply chain systems (BCT-SCS) across multiple industries are conducted to identify the BCT-enabled supply chain capabilities and their performance outcomes. Findings reveal that the present BCT-SCS efforts are mainly oriented towards improving the operational-level capabilities namely, information sharing and coordination …