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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Building 3D-Printed Widgets to Incorporate into Prototypes

Brandt, David E 01 November 2015 (has links) (PDF)
Creating interactive prototypes can be a long and difficult process. It requires expertise in various fields. Prior work in developing interactive prototypes minimize time required to make a prototype, but generally sacrifice fidelity for fluidity. Advances in 3D printing create new opportunities to prototype with greater fidelity and fluidity. We investigate the use of several kinds of sensors, including IR photo interrupters, IR photo reflectors, push button switches, and potentiometers, to create interactive prototypes. We first design a library of 3D printable interaction components, buttons, sliders, and knobs using those sensors then we develop software to transform interaction events into events in computer programs. The combinations of interaction components and sensing devices are evaluated based on their durability and ability to be printed into prototypes and used as human-computer interface devices.
2

Measurement of Surface Defects in 3D Printed Models

Shanmugham Chetiyar, Krishna Kumar, Galla Venkata Sri, Sai Sumanth January 2016 (has links)
The ease of manufacturing using additive manufacturing (3D-Printing) reduces the overall production cost compared with the traditional manufacturing techniques. Because of the benefits of 3D printing technologies, it is proposed to be used in manufacturing of different products. But there are some flaws that are causing significant effect on 3D printed models which degrades the quality of the product. Hence in order to handle these defects, different measurement techniques are needed to quantify the defects that are seen on the surface of 3D-printed models. In our study there are two experimental setups. Experimental setup one was made to find out the proper coating timing to enable measurement using two good samples without defects in different colors blue and red with same material. Different 2D and 3D parameters were used for the surface measurements are collected and noted for further research. The Defective samples are measured using the state of the art equipment at Halmstad University. Experimental setup two was made to prepare the defective samples and measure the samples. The results obtained assisted to quantify the surface defects seen in the samples. This thesis studies some of the different methods that can be implemented to measure the surface defects on the 3D printed models. A little study on the various defects formed on the 3D printed models and what are the causes for the defects on the products were performed. The results suggest different method for the defects to be measured in both industrial and home or small scale office applications.
3

Electrochemiluminescence at Bare and DNA-Coated Graphite Electrodes in 3D-Printed Fluidic Devices

Bishop, Gregory W., Satterwhite-Warden, Jennifer E., Bist, Itti, Chen, Eric, Rusling, James F. 26 February 2016 (has links)
Clear plastic fluidic devices with ports for incorporating electrodes to enable electrochemiluminescence (ECL) measurements were prepared using a low-cost, desktop three-dimensional (3D) printer based on stereolithography. Electrodes consisted of 0.5 mm pencil graphite rods and 0.5 mm silver wires inserted into commercially available 1/4 in.-28 threaded fittings. A bioimaging system equipped with a CCD camera was used to measure ECL generated at electrodes and small arrays using 0.2 M phosphate buffer solutions containing tris(2,2′-bipyridyl)dichlororuthenium(II) hexahydrate ([Ru(bpy)3]2+) with 100 mM tri-n-propylamine (TPA) as the coreactant. ECL signals produced at pencil graphite working electrodes were linear with respect to [Ru(bpy)3]2+ concentration for 9-900 μM [Ru(bpy)3]2+. The detection limit was found to be 7 μM using the CCD camera with exposure time set at 10 s. Electrode-to-electrode ECL signals varied by ±7.5%. Device performance was further evaluated using pencil graphite electrodes coated with multilayer poly(diallyldimethylammonium chloride) (PDDA)/DNA films. In these experiments, ECL resulted from the reaction of [Ru(bpy)3]3+ with guanines of DNA. ECL produced at these thin-film electrodes was linear with respect to [Ru(bpy)3]2+ concentration from 180 to 800 μM. These studies provide the first demonstration of ECL measurements obtained using a 3D-printed closed-channel fluidic device platform. The affordable, high-resolution 3D printer used in these studies enables easy, fast, and adaptable prototyping of fluidic devices capable of incorporating electrodes for measuring ECL.
4

Sintering and Characterizations of 3D Printed Bronze Metal Filament

Ayeni, Oyedotun Isaac 12 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Metal 3D printing typically requires high energy laser or electron sources. Recently, 3D printing using metal filled filaments becomes available which uses PLA filaments filled with metal powders (such as copper, bronze, brass, and stainless steel). Although there are some studies on their printability, the detailed study of their sintering and characterizations is still missing. In this study, the research is focused on 3D printing of bronze filaments. Bronze is a popular metal for many important uses. The objectives of this research project are to study the optimal processing conditions (like printer settings, nozzle, and bed temperatures) to print bronze metal filament, develop the sintering conditions (temperature and duration), and characterization of the microstructure and mechanical properties of 3D printed specimens to produce strong specimens. The thesis includes three components: (1) 3D printing and sintering at selected conditions, following a design of experiment (DOE) principle; (2) microstructure and compositional characterizations; and (3) mechanical property characterization. The results show that it is feasible to print using bronze filaments using a typical FDM machine with optimized printing settings. XRD spectrums show that there is no effect of sintering temperature on the composition of the printed parts. SEM images illustrate the porous structure of the printed and sintered parts, suggesting the need to optimize the process to improve the density. The micro hardness and three-point bending tests show that the mechanical strengths are highly related to the sintering conditions. This study provides important information of applying the bronze filament in future engineering applications.
5

A Preliminary Study of Using Plastic Molds in Injection Molding

Bartlett, Leah Paige January 2017 (has links)
No description available.
6

Characterization of Performance of a 3D Printed Stirling Engine Through Analysis and Test

Vodhanel, Julie January 2016 (has links)
No description available.
7

Investigation of Electroplating 4D Printed Antenna & Developing 3D Printed Lithium Batteries

Barnawi, Muneer Idris 10 May 2022 (has links)
No description available.
8

Supramolecular chemistry enables vat photopolymerization 3D printing of novel water-soluble tablets

Ong, J.J., Chow, Y.L., Gaisford, S., Cook, M.T., Swift, Thomas, Telford, Richard, Rimmer, Stephen, Qin, Y., Mai, Y., Goyanes, A., Basit, A.W. 12 December 2023 (has links)
Yes / Vat photopolymerization has garnered interest from pharmaceutical researchers for the fabrication of personalised medicines, especially for drugs that require high precision dosing or are heat labile. However, the 3D printed structures created thus far have been insoluble, limiting printable dosage forms to sustained-release systems or drug-eluting medical devices which do not require dissolution of the printed matrix. Resins that produce water-soluble structures will enable more versatile drug release profiles and expand potential applications. To achieve this, instead of employing cross-linking chemistry to fabricate matrices, supramolecular chemistry may be used to impart dynamic interaction between polymer chains. In this study, water-soluble drug-loaded printlets (3D printed tablets) are fabricated via digital light processing (DLP) 3DP for the first time. Six formulations with varying ratios of an electrolyte acrylate …
9

FRICTIONAL PROPERTIES OF NOVEL BRACKET SYSTEMS: AN IN-VITRO STUDY

Haverkos, Stephen M 01 January 2019 (has links)
Orthodontic brackets undergo resistance during sliding that includes classical friction, binding, and notching. Current bracket systems are hampered by these challenging forces. As a result, the clinician usually needs to apply additional forces to overcome the resistance which increases the risk of root resorption and discomfort for the patient. This study evaluated frictional properties of a novel bracket that had polytetrafluoroethylene (Teflon™) coated rollers in its design. Five types of brackets (n = 10, each), including a passive self-ligating bracket, a traditional ligated bracket, a three-dimensionally printed direct metal laser sintering (DMLS) bracket with and without Teflon™ rollers, and computer numeric controlled (CNC) machine milled bracket with Teflon™ rollers were tested. The peak resistance values were assessed at 0°, 4°, and 8° of tip on a 0.019 x 0.025” arch wire. At 8° of tip, the DMLS and the CNC milled bracket systems, both with Teflon™ rollers, exhibited less friction as compared to the other brackets tested (p
10

Direct Print Additive Manufacturing of Optical Fiber Interconnects

Tipton, Roger B. 23 March 2018 (has links)
High performance communications, sensing and computing systems are growing exponentially as modern life continues to rely more and more on technology. One of the factors that are currently limiting computing and transmission speeds are copper wire interconnects between devices. Optical fiber interconnects would greatly increase the speed of today’s electronic devices. In this study it has been demonstrated that by using a new Direct Print Additive Manufacturing (DPAM) process of Fused Deposition Modeling (FDM) of plastic and micro-dispensing of pastes and inks, we can 3D print single and multi-mode optical fibers in a controlled manner such that compact, 3-dimensional optical interconnects can be printed along non-lineal paths. We are FDM printing the core materials from a plastic PMMA material. We are dispensing a urethane optical adhesive as the core material. These materials are available in many different refractive indices. During numerical simulations of these fibers, we were able to show through manipulation of the refractive indices of the core and cladding that we can also improve the bend performance of our fibers. As a result, they can perform better as an interconnect in tight routings between components as long as the interconnect fiber distances remain less than 1 meter. Fibers have been fabricated with diameters between 77 and 17 µm across an air gap with a surface roughness of less than 450 nm and cladded and tested with transmission rates of about 46%. 12 µm fibers have successfully been fabricated on a cladded surface as a proof of concept to test the small diameter and 3D shaping capability of this process.

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