Traditional prosthetic socket fabrication is a laborious and time consuming process that involves physical measurements, plaster wrapping of the stump, plaster casting for positive mold preparation, and a thermoforming process. During the mold preparation stage, significant modifications are performed subjectively based on the prosthetist's experience to transmit an optimum load to the residual limb through the socket. Rapid Prototyping techniques have advanced rapidly during the recent decades emerging as a computer aided socket design alternative which promises a potential reduction in the fabrication time, and a more systematic design approach. In addition, 3-D scanning provides accurate and fast virtual replica of the stump which can be imported in CAD environments. Within 3-D CAD software, prosthetists are able to perform modifications precisely and store files indefinitely. This work examines the potential use of ZCorp 3-D printers to directly manufacture the thermoforming mold required for prosthetic socket manufacture. This work analyses the performance of Rapid Tooling molds for thermoformed socket based on three main parameters: pneumatic permeability, flexural strength and wear rate. The traditional material for mold casting, Plaster of Paris, is compared to materials used for three dimensional printing by Zcorp printers: zp130 and zp140 untreated as well as using them with custom and novel post treatments. To obtain the flexural strength of the different materials, three point bend tests were performed in a universal test machine using ASTM Standard D790-03 requirements. In addition, pneumatic permeability tests were performed to cylindrical specimens of the different materials following ASTM Standard D6539-00. Thermoforming tests confirm that Zcorp 3-D printed parts can serve as effective molds for thermoforming of prosthetic socket.

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Droplet generators are at the heart of many microfluidic devices developed for life science applications but are difficult to tailor to each specific application. The high fabrication costs, complex fluid dynamics, and incomplete understanding of multi-phase flows make engineering droplet-based platforms an iterative and resource-intensive process. First, we demonstrate the suitability of desktop micromills for low-cost rapid prototyping of thermoplastic microfluidic devices. With this method, microfluidic devices are made in 1 - 2 hours, have a minimum feature size of 75 μm, and cost less than $10. These devices are biocompatible and can accommodate integrated electrodes for sophisticated droplet manipulations, such as droplet sensing, sorting, and merging. Next, we leverage low-cost rapid prototyping to characterize the performance of microfluidic flow-focusing droplet generators. Specifically, the effect of eight design parameters on droplet diameter, generation rate, generation regime, and polydispersity are quantified. This was achieved through orthogonal design of experiments, a large-scale experimental dataset, and statistical analysis. Finally, we capitalize on the created dataset and machine learning to achieve accurate performance prediction and design automation of flow-focusing devices. The developed capabilities are captured in a software tool that converts high-level performance specifications to a device that delivers the desired droplet diameter and generation rate. This tool effectively eliminates the need for resource-intensive design iterations to achieve functional droplet generators. We also demonstrate the tool’s generalizability to new fluid combinations with transfer learning. We expect that our newly established framework on rapid prototyping, performance characterization informed by design of experiments, and machine learning guided design automation to enable extension to other microfluidic components and to facilitate widespread adoption of droplet microfluidics in the life sciences.

To evaluate the effectiveness of a rapid prototyping into a curriculum, a study was conducted requiring students to conceive a design and create a model. Students were randomly selected to be given access to the rapid prototype or to create the models by hand. The students' models were evaluated on scale, design, and craftsmanship. Students participated in a survey consisting of perceptions of design feedback and difficulties as well as interests and affective traits. The study utilized qualitative data investigating the instructors' perceptions prior to implementing rapid prototyping into the curriculum and its correlation to observed events. The study found statistical differences in scale and craftsmanship scores, as well as monetary and time investments with rapid prototyping producing better models at a higher cost with less time invested. The data also suggested rapid prototyping changed the design process as well as shifting affective dispositions within the project.

Rapid, point-of-care infectious disease diagnostics have the potential to dramatically improve health care provision in low-income world regions. However, the development of technologies such as electrochemical DNA biosensors is hindered by slow turnaround times from design to working prototype. In order to facilitate biosensor development, a rapid prototyping method has been applied to the fabrication of wrinkled nano-/micro-structured electrodes in this work. An electrocatalytic DNA hybridization detection scheme is optimized for use with the wrinkled electrodes by adjusting the concentrations of redox agents FiCN and RuHex. Characterization of the electrodes by electrochemical and fluorescence-based methods showed tunability of important detection-related parameters – namely, the density of DNA probe molecules and the hybridization-induced electrocatalytic signal change – by altering parameters of deposition time, molar fraction of DNA probes relative to diluent molecules, and thickness of the wrinkled gold film. / Thesis / Master of Applied Science (MASc)

Additive Manufacturing – AM – which is a part of a generic term, Rapid Prototyping, comprises a family of different techniques to build 3D physical objects sequentially stacking a series of layers over each other. These techniques have been evolving over three decades with more materials available, improving the techniques as well as generating new ones. However they are all based on the same explained idea. In this research the main AM methods followed with the opportunities of application and cost drivers is sought. For this purpose, after reviewing different processes and techniques, the application of them in diverse industry sectors is described. The influence of AM in production systems, so called Rapid Manufacturing (RM) is also discussed in terms of lean and agile concepts. Time and cost are the most important factors for the production systems to be responsive and productive respectively. Thus, case based application of RM is evaluated to clarify how AM acts in different production systems regarding these factors. To decide which method is the best, strongly depends on the case. But what has been derived from the analysis, is that however in comparison with traditional methods, AM applies more economically in one-off jobbing, yet the economy of scale exists to some extent. In fact it depends on the machine capacity utilization as well as batch size which indicates the machine volume usage. Despite all the improvements in the last three decades, the application of AM is still not widespread. Since the demand, use, applications and materials as well as its techniques are still in a growing phase, a brighter future is seen for the upcoming customer oriented market. / Additive Manufacturing – AM – som är del av en generell term, Rapid Prototyping, består av en familj olika tekniker för att bygga 3D fysiska objekt genom att sekventiellt lägga lager ovanpå varandra. Dessa tekniker har utvecklats över de senaste tre decennierna, där nya material blivit tillgängliga, teknikerna har förbättrats och nya har skapats, men i slutändan bygger de alla på en och samma idé. Det projekt undersöks de huvudsakliga AM -metoderna, deras applikationer och kostnadsdrivare. Här görs först en litteraturstudie av olika tekniker och processer varefter deras användning inom olika industrier undersöks. Den influens AM har i produktionssystem, s.k. Rapid Manufacturing (RM), diskuteras också i förhållande till lean och agila koncept. Eftersom tid och kostnad är de viktigaste faktorerna för tillgänglighet respektive produktivitet utvärderas case-baserad användning av RM utifrån dessa faktorer för att förklara hur AM fungerar i produktionssystem. Att besluta vilken metod som är bäst, är starkt case-baserad. Men det som framkommit från analysen är att i jämförelse med traditionella metoder, är AM mer ekonomiskt vid enstyckstillverkning, men stordriftsfördelar finns i någon utsträckning. Faktiskt det beror på maskinens kapacitetsanvändning och satsstorlek som indikerar maskinens volymanvändning. Trots alla förbättringar under de senaste tre decennierna är användandet av AM ännu inte utbrett. Eftersom efterfrågan, användning, tillämpning och material så väl som dess tekniker fortfarande befinner sig i en tillväxtfas spås en ljusare framtid för en växande kundorienterad marknad.

As technology for manufacturing small scale prototypes of aeroplanes has become cheaper and more easily viable, the process of Rapid Prototyping has become more common. Rapid Prototyping allows for the fundamental aerodynamic qualities of a geometric body to be tested in a wind tunnel using a small scale prototype. This means smaller prototypes of aircraft can be manufactured more rapidly and at a lower cost, allowing for more extensive testing of a design’s final aerodynamic qualities before any actual full-size production. In order to gain a better insight in the behaviours of the full-sized aircraft itself, a downscaled version of the KTH project UAV ALPHA has been deigned for testing in a low speed wind tunnel. The design will be used in further testing to help confirm simulations and estimations done on the ALPHA of its aerodynamic performance.

The focus of this thesis was to investigate how PCL and PLGA react to the heat exposure that comes with the MEW process over a defined timespan. To assess the thermal stability of PCL during MEW over 25 d, an automated collection of fibers has been used to determine the CTS on each day of heating for three different temperatures. PCL is exceptionally stable over 25 d at 75 °C, whereas for 85 °C and 95 °C a slight upward trend during the last 10 d could be observed, which is an indication for thermal degradation. Same trend could be observed for diameter of fibers produced at a fixed collector speed. For all temperatures, CTS during the first 5 d decreased due to inhomogeneities of the melt. Physical analysis of the fibers by XRD and mechanical testing showed no significant changes. To investigate the chemical details of the thermal durability, PCL was artificially aged over 25 d at 75 °C, 85 °C and 95 °C. Data from GPC analysis and rheology revealed that PCL is degrading steadily at all three temperatures. Combined with GC-MS analysis, two different mechanisms for degradation could be observed: random chain scission and unzipping. Additional GPC experiment using a mixture of PCL and a fluorescence labelled PCL showed that PCL was undergoing ester interchange reactions, which could explain its thermal stability. PLGA was established successfully as material for MEW. GPC results revealed that PLGA degraded heavily in the one-hour preheating period. To reduce the processing temperature, ATEC was blended with PLGA in three mixtures. This slowed down degradation and a processing window of 6 h could be established. Mechanical testing with fibers produced with PLGA and all three blends was performed. PLGA was very brittle, whereas the blends showed an elastic behavior. This could be explained by ester interchange reactions that formed a loosely crosslinked network with ATEC. / Ziel dieser Arbeit war, die Veränderung von PCL und PLGA während des MEW-Verfahrens bei bestimmten Temperaturen über einen definierten Zeitraum zu untersuchen. Für die Bewertung der thermischen Stabilität von PCL während des MEW-Prozesses über 25 d wurden Fasern in einem vorgegebenen Druckmuster gesammelt, um täglich die CTS für drei verschiedene Temperaturen zu bestimmen. Allgemein war PCL bei 75 °C über 25 d thermisch stabil. Allerdings nahm die CTS bei allen Temperaturen während der ersten 5 d aufgrund von Inhomogenitäten der Schmelze ab. Bei 85 °C und 95 °C wurde in den letzten 10 d ein leichter Anstieg der CTS beobachtet, was auf thermische Degradation hinweist. Dieser Anstieg war ebenfalls im Durchmesser der Fasern zu beobachten, die mit konstanter Kollektorgeschwindigkeit hergestellt wurden. Die physikalische Untersuchung der Fasern mittels XRD und mechanischer Tests ergab keine signifikanten Veränderungen. Um die Chemie der thermischen Beständigkeit zu untersuchen, wurde PCL über 25 d bei 75 °C, 85 °C und 95 °C künstlich gealtert. GPC- und rheologische Analysen zeigten, dass PCL bei allen Temperaturen stetig abbaut. Mit der GC-MS-Analyse konnten zwei Abbaumechanismen beobachtet werden: zufällige Kettenspaltung und Unzipping. GPC-Messungen mit einer Mischung aus PCL und einem fluoreszenzmarkierten PCL zeigten, dass es zu Esteraustauschreaktionen kommt, welche die thermische Stabilität erklären. PLGA wurde erfolgreich als Material für MEW etabliert. Die GPC-Daten zeigten, dass PLGA während der einstündigen Aufheizphase stark abgebaut wurde. Um die Verarbeitungstemperatur zu senken, wurden drei Mischungen mit verschiedenen Verhältnissen von PLGA und ATEC hergestellt. Dadurch verlangsamte sich der Abbau, wodurch ein Verarbeitungsfenster von 6 h erreicht wurde. Mechanische Tests zeigten für PLGA ein sprödes, für die Mischungen ein elastisches Verhalten. Dies kann durch Esteraustauschreaktionen mit ATEC erklärt werden, durch die ein Polymernetzwerk entstehen könnte.

The purpose of this study is to examine the position and use of an upper extremity prosthetic simulator on non-amputees. To see how a 3D printed prosthetic simulator can be optimized to serve the user correctly and accurately. In addition, this study examines the improvement of the Hosmer 5X Prosthetic Hook with the addition of newly designed trusses on to the prosthetic, as well as utilizing a new manufacturing method known as 3D printing. These topics are important because there is no standardized prosthetic simulator for schools and research facilities to use. Off the shelf prosthetic simulator cost upwards of $2000, often too expensive for early stage research. By optimizing the Hosmer 5X Prosthetic Hook with 3D printing, this new opportunity could allow amputees, from a range of income classes, to have access to a wide variety of prosthetics that are strong enough to support everyday living activities. A low-cost prosthetic that is easily distributable and accessible can give people a chance to regain their independence by giving them different options of efficient prosthetic devices, without having to spend so much. The devices in this project were design and analyzed on SOLIDWORKS, 3D scanned on the Artec Space Spider, and surfaced on Geomagic Wrap. Key results include developing a low-cost, robust prosthetic simulator capable of operating a Hosmer 5X Prosthetic hook, as well as developing a lighter version of the Hosmer 5X Prosthetic Hook that is more cost efficient and easily obtainable to the population around the world.

This paper summarizes a design project entitled "Social Scriptures" completed for the AudioVisual Department of The Church of Jesus Christ of Latter-day Saints (The Church). The purpose of the design project was to prototype a web-based computer application that could be used by Church members to study the scriptures in an online social context. Originally, the project was designed to be a part of the Facebook Application Platform in order to leverage both the extensive existing social connections of Church members as well as deliver the application in a setting where many Church members already spend a good deal of their time. Through the cyclic design processes of feedback and evaluation, the project was later generalized to not necessarily depend on the Facebook Platform, but rather create a system from the existing member account information coupled with scriptural content that can function inside of a social network or on its own. The evolution of the design process towards using a rapid prototyping methodology allowed for quick revisions, lower stakes testing, and more overall flexibility in the design. The various stages of the design process, including revisions and prototypes, are shown and discussed in this paper.