Dissertations / Theses on the topic 'Applications; Educational; Rapid Prototyping'

Published Article
Long-term growth in the additive fabrication industry will come from designs that are difficult, time-consuming, costly, or impossible to produce using standard techniques. Growth will occur with advances in the current additive processes, coupled with breakthroughs in new materials, which are expected to emerge over the next five to 10 years. These advanced materials will better satisfy the design requirements of many new products. The paper considers currently available technologies and discusses recent advancements in direct metal freeform fabrication and its potential of revolutionising the medical industry.

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.

In this study, a two axes linear positioning system for testing and applying different rapid prototyping techniques was designed and manufactured. A cable/ pulley mechanism is utilized in the system for transmitting motion from motors into linear motion. Use of a cable/ pulley mechanism overcomes the problems resulting from the utilization of conventional drive systems like ball screws and decreases the overall cost of the system. The carriage elements of both axes were designed and manufactured by using investment casting. The molds used in casting were also designed and manufactured within this study. The designed system is controlled by a servo motion control system composed of a motion controller, DC servo motors and linear encoders. All elements of the motion control system were selected, integrated and programmed within the scope of the study.

Approved for public release; distribution is unlimited
The modern engineer has a myriad of new tools to assist in the design and implementation of ever increasingly complex control systems. A promising emerging technology is rapid prototyping. By totally integrating the development process, a Rapid Prototyping System (RPS) takes the designer from initial concept to testing on actual hardware in a systematic, logical sequence. At the Naval Postgraduate School (NPS), we have applied the concept of rapid prototyping to the discipline of flight control. The NPS RPS consists of a commercially available rapid prototyping software suite and open architecture hardware to permit the greatest possible range of control and navigation projects. The RPS is crucial in that it allows students to participate in projects from the initial concept to the flight testing phase of the design process. This thesis will describe in detail two of these projects; the development of an Airspeed Controller using the RPS tools; and the integration of a Voice Control System developed by ViA, Inc. of Northfield, Minnesota. Both projects demonstrate the inherent flexibility and risk reduction of the rapid prototyping a roach to system design.

Le développement d’applications de traitement du signal pour des architectures multi-coeurs embarquées est une tâche complexe qui nécessite la prise en compte de nombreuses contraintes. Parmi ces contraintes figurent les contraintes temps réel, les limitations énergétiques, ou encore la quantité limitée des ressources matérielles disponibles. Pour satisfaire ces contraintes, une connaissance précise des caractéristiques des applications à implémenter est nécessaire. La caractérisation des besoins en mémoire d’une application est primordiale car cette propriété a un impact important sur la qualité et les performances finales du système développé. En effet, les composants de mémoire d’un système embarqué peuvent occuper jusqu’à 80% de la surface totale de silicium et être responsable d’une majeure partie de la consommation énergétique. Malgré cela, les limitations mémoires restent une contrainte forte augmentant considérablement les temps de développements. Les modèles de calcul de type flux de données sont couramment utilisés pour la spécification, l’analyse et l’optimisation d’applications de traitement du signal. La popularité de ces modèles est due à leur bonne analysabilité ainsi qu’à leur prédisposition à exprimer le parallélisme des applications. L’abstraction de toute notion de temps dans les diagrammes flux de données facilite l’exploitation du parallélisme offert par les architectures multi-coeurs hétérogènes. Dans cette thèse, nous présentons une méthode complète pour l’étude des caractéristiques mémoires d’applications de traitement du signal modélisées par des diagrammes flux de données. La méthode proposée couvre la caractérisation théorique d’applications, indépendamment des architectures ciblées, jusqu’à l’allocation quasi-optimale de ces applications en mémoire partagée d’architectures multi-coeurs embarquées. L’implémentation de cette méthode au sein d’un outil de prototypage rapide permet son évaluation sur des applications récentes de vision par ordinateur, de télécommunication, et de multimédia. Certaines applications de traitement du signal au comportement très dynamique ne pouvant être modélisé par le modèle de calcul supporté par notre méthode, nous proposons un nouveau méta-modèle de type flux de données répondant à ce besoin. Ce nouveau méta-modèle permet la modélisation d’applications reconfigurables et modulaires tout en préservant la prédictibilité, la concision et la lisibilité des diagrammes de flux de données
The development of embedded Digital Signal Processing (DSP) applications for Multiprocessor Systems-on-Chips (MPSoCs) is a complex task requiring the consideration of many constraints including real-time requirements, power consumption restrictions, and limited hardware resources. To satisfy these constraints, it is critical to understand the general characteristics of a given application: its behavior and its requirements in terms of MPSoC resources. In particular, the memory requirements of an application strongly impact the quality and performance of an embedded system, as the silicon area occupied by the memory can be as large as 80% of a chip and may be responsible for a major part of its power consumption. Despite the large overhead, limited memory resources remain an important constraint that considerably increases the development time of embedded systems. Dataflow Models of Computation (MoCs) are widely used for the specification, analysis, and optimization of DSP applications. The popularity of dataflow MoCs is due to their great analyzability and their natural expressivity of the parallelism of a DSP application. The abstraction of time in dataflow MoCs is particularly suitable for exploiting the parallelism offered by heterogeneous MPSoCs. In this thesis, we propose a complete method to study the important aspect of memory characteristic of a DSP application modeled with a dataflow graph. The proposed method spans the theoretical, architecture-independent memory characterization to the quasi-optimal static memory allocation of an application on a real shared-memory MPSoC. The proposed method, implemented as part of a rapid prototyping framework, is extensively tested on a set of state-of-the-art applications from the computer-vision, the telecommunication, and the multimedia domains. Then, because the dataflow MoC used in our method is unable to model applications with a dynamic behavior, we introduce a new dataflow meta-model to address the important challenge of managing dynamics in DSP-oriented representations. The new reconfigurable and composable dataflow meta-model strengthens the predictability, the conciseness and the readability of application descriptions

Published Article
This paper identifies the most significant technological developments made in medical applications of rapid prototyping and manufacturing (RP&M) over the past decade. This assessment is based on a retrospective analysis of the research undertaken by the Medical Applications Group of the National Centre for Product Design and Development Research (PDR), based at the University of Wales lnstitute Cardiff (UWIC). UK. The paper describes the state of technology at the inception of the Group in 1998 and then highlights the significant technological developments that impacted on the activities of the Group over the decade to 2008. The paper will also discuss how these technologies have developed since their initial implementation. The paper will conclude with suggested directions future work should take in order to meet clinical and technical needs.

This paper summarizes a design project entitled "Choose Your Own Teaching Adventure" completed for the Instructional Psychology and Technology Department at Brigham Young University. The purpose of the design project was to prototype a learning tool that instructs beginning pre-service teachers in the classroom application of the principles of behaviorism. Originally, the project was designed to be a static learning object that would be combined with other similar learning modules for additional topics of an Educational Psychology course. At the conclusion of the first prototyping round, however, the project was generalized to become a testing ground for a simulation builder project that would allow other instructors to create their own learning simulation based on the findings of this prototype. The Rapid Prototyping methodology used in this project allowed for quick revisions, lower stakes testing, and more flexibility in the design. The various stages of the design and evaluation process, including revisions and prototypes, are shown and discussed in this paper.

The purpose of this study was to investigate the implications of additive manufacturing on industrial design profession and designers through an explorative study. Through a literature survey, implications of additive manufacturing technologies on industrial designers and industrial design profession were explored. Expanding literature survey with on-line searches, several experimental and commercial application examples of rapid manufacturing of products were identified. These identified examples were then used for a qualitative evaluation on the implications of additive manufacturing for the industrial design profession and designers through semi-structured interviews conducted with seven professional industrial designers having experience with rapid manufacturing in Istanbul Turkey. The research concluded with significant implications of additive manufacturing having the potential to cause paradigm shifts in industrial designer&rsquo
s role, definition of the profession and design process. The conclusions derived include suggestions to exploit the potential brought by these technologies and their applications.

Despite the last 60 years have seen major advances in many scientific and technological inputs of drug Research and Development, the number of new molecules hitting the market per billion US dollars of R&D spending has been declined steadily during the same period. The current scenario highlights the need for new research tools to enable reduce costly animal and clinical trials while providing a better prediction about drug efficacy and security in humans A recent emerging approach to improve the current models is emerging from the field of microfluidics, which studies systems that process or manipulate tiny amounts of fluids using channels with dimensions of tens to hundreds of micrometers. Combining microfluidics with cell culture, scientists gave rise to a new field named “Organ-on-chip” (OOC). Microfluidic OOCs are advanced platforms designed to mimic physiological structures and continuous flow conditions, thus allowing the culture of cells in a friendlier microenvironment. This thesis, titled “Cell culture interfaces for different organ-on-chip applications: from photolithography to rapid-prototyping techniques with sensor embedding”, aims to design, simulate and test new OOC devices to reproduce cell culture interface under flow conditions. The work has a focus on the exploration of novel fabrication techniques which enable rapid prototyping of OOC devices, reducing costs, time and human labor associated to the fabrication process. The final objective is to demonstrate the viability of the devices as research tools for biological problems, applying them to the tubular kidney and the blood brain barrier (BBB). To achieve the objective, at least three device version have been developed: 1) OOCv1, fabricated by multilayer PDMS soft lithography; 2) OOCv2, fabricated in thermoplastic by layered object manufacturing using both a vinyl cutter and a laser cutter, integrating standard fluidic connectors alone (OOCv2.1) or together with embedded electrodes (OOCv2.2); 3) OOCv3 using a mixed technique of laser cut and 3D printing by stereolithography. All devices are fabricated using biocompatible materials with high optical quality and an embedded commercial membrane. The biological experiments with renal tubular epithelial cells, realized on OOCv1 and OOCv2.1 devices, demonstrated the viability of the device for culturing cells under flow conditions. The study realized on fatty acid oxidation and accumulation in cells exposed to physiological and diabetogenic oscillating levels of glucose suggest a possible positive role of shear stress in activation of fatty acid metabolism. The studies were performed using a compact experimental unit with embedded flow control which reduce significatively the complexity and cost of the fluidic experimental setup. The biological experiments on the BBB confirmed viability of OOCv2.1 and OOCv2.2 for compartmentalized co-culturing of endothelial cells and pericytes. The formation and recovery of the barrier after disruptive treatment has been assessed using different techniques, including immunostaining, fluorescence and live phase contrast imaging, and electrical impedance spectroscopy. The repeatability of measurements using electrodes was verified. A model to classify measurements from different timepoints has been developed, resulting in accuracy of 100% in learning and 90% in testing case. Results are confirmed by imaging data, which also suggest a critical role of pericytes in the development, maintenance, and regulation of BBB, in accordance with the literature.
En los últimos años está emergiendo una nueva propuesta para mejorar los modelos actuales en el estudio de nuevos fármacos. Mediante la fusión de cultivos celulares y microfluídica ha nacido un nuevo campo de aplicación denominado “Órgano-en-un-chip” (OOC), donde se recrea un entorno fisiológico capaz de reproducir unidades funcionales mínimas de diversos órganos del cuerpo humano. Un elemento importante para el desarrollo de dispositivos OOC es la reproducción de zonas de interacción entre varios tejidos formados por diferentes tipos celulares. Esta tesis, titulada “Interfaces de cultivo celular para diferentes aplicaciones de OOC: desde fotolitografía a técnicas de prototipado rápido con inclusión de sensores”, tiene como objetivo el diseño, simulación y evaluación de dispositivos OOC capaces de reproducir superficies de contacto de tejidos contiguos expuestos a flujo. El trabajo está enfocado a la exploración de nuevas técnicas de fabricación que permitan el prototipado rápido de dispositivos OOC, reduciendo costes, tiempo y mano de obra asociada a dicha fabricación. El objetivo final es demostrar la utilidad de los dispositivos como herramientas de investigación para problemas biológicos, aplicándolos en esta tesis al estudio del túbulo renal y de la barrera hematoencefálica. Para ello se han fabricado tres versiones de dispositivos: 1) OOCv1 fabricado por litografía suave en múltiples capas de PDMS; 2) OOCv2 fabricado con cortadora de vinilo y cortadora láser en múltiples capas de materiales termoplásticos y con electrodos integrados en la versión OOCv2.2; 3) OOCv3 fabricado mediante impresión 3D por esterolitografía. Todos los dispositivos están hechos de materiales biocompatibles de alta calidad óptica, con conectores fluídicos y una membrana comercial integrada. Los experimentos biológicos sobre túbulo renal, realizados en los dispositivos OOCv1 y OOCv2, han demostrado la viabilidad de los dispositivos, integrados con un sistema de flujo, para estudios de la metabolización de ácidos grasos en el riñón relacionados con condiciones diabetogénicas. Los experimentos biológicos sobre la barrera hematoencefálica han confirmado la viabilidad de OOCv2 para el cocultivo compartimentado de células endoteliales de cerebro y pericitos. La integración de electrodos en el OOCv2.2 ha demostrado ser una técnica fiable para la medición de la integridad de barreras biológicas de modo no-invasivo, libre de etiqueta (“label-free”), y a tiempo real gracias a la espectroscopía de impedancia.

Free-space optical interconnects (FSOIs) are widely seen as a potential solution to present and future bandwidth bottlenecks for parallel processing applications. This thesis will be focused on the study of a particular FSOI system called Optical Highway (OH). The OH is a polarised beam routing system which uses Polarising Beam Splitters and Liquid Crystals (PBS/LC) assemblies to perform reconfigurable interconnection networks. The properties of the OH make it suitable for implementing different passive static networks. A technology known as Rapid Prototyping (RP) will be employed for the first time in order to create optomechanical structures at low cost and low production times. Off-theshelf optical components will also be characterised in order to implement the OH. Additionally, properties such as reconfigurability, scalability, tolerance to misalignment and polarisation losses will be analysed. The OH will be modelled at three levels: node, optical stage and architecture. Different designs will be proposed and a particular architecture, Optimised Cut-Through Ring (OCTR), will be experimentally implemented. Finally, based on this architecture, a new set of properties will be defined in order to optimise the efficiency of the optical channels.

Engineering educators the world over are being faced with the dilemma of combining traditional mathematically intensive courses, like Control Systems and Robotics with advances in computational hardware and software. This is because it is impractical to include both software engineering issues as well as conventional course content. A solution to the problem lies in Rapid Prototyping technology to develop and design software, for application on PC's and embedded systems. Rapid Prototyping, based on automatic code generation, allows users to develop advanced software on high level graphical platforms like Simulink® and LabView®, while " hiding" the underlying layers of complex code. This approach allows the advanced hardware, traditionally reserved for software engineers, to be accessed by a much wider audience and is an ideal educational tool. This thesis presents the complete development of the Rapid Application Development Environment (RADE). The RADE system customises the Mathworks Real Time Workshop (RTW) revision 11 for application on both standalone and networked DS? cards. The functionality of the RTW is incorporated into the RADE system. This affords the user seamless code generation, downloading, on-line parameter tuning and on-line data visualisation with storage capability. An added advantage of the RADE system is its easy portability to multiple target platforms, which is demonstrated by its implementation on two different DSP cards. Finally the functionality of the RADE system is demonstrated as an educational tool, with the demonstration of a DC motor speed and position controller.
Thesis (M.Sc.Eng.-University of Natal, Durban, 2001.

碩士
明志科技大學
機電工程研究所
101
How to effectively shorten product development time, keep the market leading position with the latest products that fit market demands have been the focus of every company. Therefore, whoever introduces the new product in the shortest time with minimal funds can be the winner. As a result, the rapid prototyping technology has been developed. Rapid tooling technology can be regarded as the extension of rapid prototyping technology such that its benefit at development stage can be directly extended to production. The use of rapid tooling technology can allow rapid batch production of required products thus achieving the goal of rapid manufacturing. Up to now, we still rely on manual approach to determine whether or not the silicone has been fully cured during solidification process. However, this method is rather unscientific with large errors. In order to solve this issue, in this study a set of optical detection system for silicone curing time has been established, where the laser is used to monitor the silicone curing from liquid state to solid state, and the variations of laser transmission power and temperature are used to measure the silicone curing time. The differences in laser transmission powers of liquid state and solid state of five kinds of silicone have been completely analyzed and investigated. Based on the results of this analysis, the variation of silicone temperature, and the manual measurement result, the silicone curing time identification criteria has been proposed and the prediction equation of silicone curing time has been established with maximum measurement error within 8.26%. In addition, the general method of measuring pH value of solution after removal of supporting material is based on the use of pH meter. This method is more accurate, but there are also some shortcomings such as the reliability of pH meter after long-term measurement, the contamination of solution, and the accuracy of measuring high temperature solution. In order to overcome aforementioned deficiencies, the laser is used in this study as the detection light source in coordination with a spectrometer to establish an in-line optical detection system for monitoring pH value of solution after removal of supporting material such that proper compensation can be applied to maintain optimal pH value, and the efficiency of removal of supporting material can be improved. The results of this study have indicated the estimated error of pH value of solution after removal of supporting material to be within 4.42% while saving of up to 70.3% of the time required for removing supporting material. The features of this system also include: non-contact detection, rapid measurement, and high reliability and stability.

碩士
國立交通大學
建築研究所
105
Tri-axis prototyping is so far the most prevalent technique in rapid prototyping. A research project was conducted with an aim to provide designers a faster alternative for prototyping. The proposed technique utilizes centrifugal force to create a semi-weaving effect which cannot be achieved by the conventional 3D printing technology. Based on practical experiments of thermoplastic material (ABS,PLA,TPU, PP, thermoplastic crystal, polyfoam glue of materials), this paper discusses prototyping in terms of the making process , use of materials and other factors associated with the control of filament weaving effect. Furthermore, designing and embedding molds or frames within the range of filament spray allows composite structure units to form into designed shapes. With this technique, a more efficient way in large-scale rapid prototyping is proposed and tested.

碩士
長庚大學
機械工程研究所
89
Abstract Clinical surgeons have always needed to perform anaplasties for patients, due to inborn or acquired factors, who are injured in the skull, face or limbs. At present, anaplasties are invariably executed solely based on the surgeon''s experiences - planning the steps of the surgery and designing the shape of the implant all on an x-ray film. The entire process not only consumes time but also affects the quality of the implant. In modern times, the technology of "Reverse Engineering" has been broadly applied to industries of moulds, aerospace and automobiles but still not so much in the medical field. The purpose of our research, is to develop RE for medical application through the aid of CAD/CAM、RP/RT and image scanning and regrouping technologies. As a result, our findings will help doctors perform skull and facial implantations、darns for artificial ears、designing and making the template for orientation of the lower jaw and pre-surgery-route-plannings and simulations. In addition, our study will also employ medical RE and RP/RT technologies in designing and manufacturing even-pressured shoe insoles for rehabilitation of diabetics. The content of our thesis includes 4 sub-topics: making and development of the flow path of medical RE、making and development of the application of implantation for skull and facial surgeries、3D images and physical models for the application of surgical simulations and finally, designing and manufacturing even-pressured shoe insoles for rehabilitation of diabetics. The first section of the thesis defines the distinguishing characteristics for the technology of medical RE/RP and sets forth the actual-clinical application and verification of CT、Thresholding、Stack Region Growing、Image Segmentation and Surface Separation. The second section of the thesis deals with the manufacture and application techniques of implants for skull and facial surgeries which includes repairment implantation、darns for artificial ears、designing and making of the template for orientation of the lower jaw. Moreover, actual-clinical cases will be presented to prove the practicability of our newly developed techniques. The third section of the thesis adopts methods of "Digital Imaging" and "Physical Modeling" in pre-surgery-route-plannings and simulations for skull and facial surgeries. Besides comparing and contrasting the two methods mentioned above, we will also verify the feasibility of the surgical procedures through a light-hardening-resin model for surgical simulation. The final section of the thesis, assisted with the foot-pressure measuring system developed by my instructor and integrated with the image collecting system, we have developed a "Simultaneous Foot Profile and Pressure Distribution Measuring System". In addition, we have also developed the CAD techniques for designing even-pressured shoe insoles for rehabilitation of diabetics. In completion of our research, our developed medical RE manufacturing flow path and the application techniques of implantation will be used in conjunction with the clinical needs through CAD manufactured implants、artificial ears or positioning board. Besides shortening the time for performing a surgery, our methods will also improve the quality of the surgery. Furthermore, the proof of the application of "Digital Imaging" and "Physical Modeling" in surgical plannings can provide clinical surgeons pre-surgery-route-plannings and simulations. In which, DI offers repetitive-surgical simulations and PM offers the physical segmentation drills for doctors. As for the technologies of "Simultaneous Foot Profile and Pressure Distribution Measuring System" and the even-pressured shoe insoles for rehabilitation of diabetics, will effectively aid in the production of even-pressured shoe insoles for rehabilitation of diabetics with the use of RE and RP. Our method not only establishes a unique style of making the rehabilitation shoes but will also bring their healing power into full play. Key Words: Medical Reverse Engineering (MRE)、Rapid Prototyping (RP)、 Repairment Implantation、Artificial Ear Ornament、 Lower Jaw Position Board、Rehabilitation Even-Pressured Shoe Insole.

碩士
國立臺北科技大學
生化與生醫工程研究所
101
Tissue engineering that repairs damage tissues through the porous, degradable scaffold to deliver cells, genes, and proteins. In tissue engineering, scaffolds serve as temporary surrogates for the extracellular matrix and guide for tissue ingrowth to regenerate the tissue. The ideal scaffolds should have (Ⅰ) An appropriate surface chemistry characteristics to facilitate cell attachment, proliferation and differentiation. (Ⅱ) An extensive network of interconnecting pores through which oxygen and nutrients are provided cells to grow. (Ⅲ) Adequate mechanical strength and biodegradation rate. (Ⅳ) High biocompatibility for cells to attach and proliferate. Conventional techniques methods do not control precisely over the pore size, pore geometry, pore interconnectivity and the spatial distribution of pores, Using rapid prototyping technology to facbricate scaffold which has interconnected porous and facilitate transport of nutrients and metabolite into and out of the scaffold. Highly porous of scaffolds facilitate cell growth and tissue formation. In the present study, we fabricated chitosan/collagen scaffold as the exprientment group and chitosan scaffold as the control group. Further, we compared two scaffolds differences between physical characteristics and biocompatibility characteristics. Results show that using rapid prototyping technology to fabricate the chitosan /collagen scaffold which structure has stable mechanical strength, and which porous properties has good biodegradability and biocompatibility which can promote fiberblast growth to repair skin.

碩士
長庚大學
機械工程研究所
94
The precise manufature of micro-structure componets is the mainly significant technique of Micro-Electro-Mechanical Systems (MEMS). According to the definition of Science & Technology Policy Reseach Center (STPI) micro-structure component means that size or precision is between 10 and 100 μm. Presently, manufacturing micro-structure components have to use semiconductor fabrication method for the most part. The semiconductor fabrication method for micro-structure components has very expensive and complex fabrication process, which requires mask, a huge clean room and lithography environment. However, it is not a smart method to fabricate micro-structure components if these sizes or precision are between 10 and 100 μm. In recently years, rapid prototyping technique has become a new method for making industrial components. It is an automated manufacturing process that quickly builds physical models from three-dimention (3-D) prototype computer-aided design files. It also can dramatically speed up design and manufacturing processes and substantially reduced the cost. Even so, most of the rapid prototyping machines only can fabricate components which precision are larger than 100 μm and are not suitable to manufacture micro-structure components. Therefore, the aim of this research is to design and construct a new system, Ultra-violet Lithography Variable Focal Length Rapid Prototyping system, without all the above mentioned disadvantages. And by using the new system to fabricate micro-structure components, we can reduce the cost and fabricate micro-structure components near to 10 μm. This research comprises of three different parts. The first part was the hardware develop of the “Ultra-violet Lithography Variable Focal Length Rapid Prototyping system” machine.The work included function evaluation of platform , setup of work manual, frame design and structural design by Solidwork, pressure-damper module develop, spin coating platform develop, a dust-collecting plant design, material supply module develop, Variable Focal Length motion platform develop, micro motion platform set-up, adaptive light source control module develop, and IC control module design. The second part was the software develop of the “Ultra-violet Lithography Variable Focal Length Rapid Prototyping system” machine. The work included CAD file slicing for micro-structure component, UV exposure profile programming and human-machine interface software design. This involved using CopyCAD and Visual Basic to design the software window platform for micro-structure component slicing, using PowerMill and Visual Basic to design the software window platform for UV exposure profile programming and using Visual Basic to design the human-machine interface software window platform. The third part was to combine the “Ultra-violet Lithography Variable Focal Length Rapid Prototyping system” machine with the CAD file slicing module for micro-structure component and UV exposure profile programming module and builded the physical machine. This includes the testing of both hardware and software of the machine. Lastly, to test the machine by fabricating micro-structure components. Recently, we can reduce the disadvantages of the traditional semiconductor fabrication method by developing our micro-structure components within a comparatively small dust-free and lithography environment. In addition, this system can decrease the cost and is capable of producing more micro-structure components up to 10 μm.

Applications involving high electrical conduction require complex components that are difficult to be manufactured by conventional processes. Laser sintering (LS) is an additive manufacturing technique that overcomes these drawbacks by offering design flexibility. This study focuses upon optimizing the process of laser sintering to manufacture functional prototypes of components used in high electrical conduction applications. Specifically, components for two systems – high current sliding electrical contacts and fuel cells – were designed, manufactured and tested. C-asperity rails were made by LS and tested in a high current sliding electrical setup. Corrugated flow field plates were created by LS and their performance in a direct methanol fuel cell (DMFC) was tested. This is the first experimental attempt at using laser sintering for manufacturing such complex components for use in high electrical conduction applications. The second part of this study involves optimization the laser sintering process. Towards this, efforts were made to improve the green strength of parts made by LS. Particle size of graphite/ phenolic resin and addition of nylon/11 and wax were tested for their effect upon green strength. Of these, significant improvement of green strength was observed by altering the particle size of the graphite/ phenolic resin system. New methods of improving green strength by employing fast cure phenolic resins with carbon fiber additions were successfully demonstrated. This study also identified a binder system and process parameters for indirect LS of stainless steel –for bipolar plate compression/ injection mold tooling. All the experimental results of this study lead us to believe that laser sintering can be developed as a robust and efficient process for the manufacture of specialized components used in advanced electrical conduction systems.
text

Web-based learning should move away from static transmission of instruction to dynamic pages for effective interactive learning. Furthermore, automated assessment of learning should move beyond rigid quizzes or multiple-choice questions. This study describes the design, development, implementation, testing and evaluation of two prototypes of an electronic assessment tool to enhance the effectiveness of automated assessment. The tool was developed in the context of a distance-learning organisation and was built according to a development research model entailing a cyclic design-intervention-outcomes process. The first variant, E-Grader, was developed to test an algorithm for assigning marks to open-ended textual responses. The second variant, Web-Grader, was an interactive web-based extension of E-Grader. It provided immediate interactive support to students as they responded textually to content-based questions. This multi-disciplinary study incorporates principles and techniques from software engineering, formal computer science, database development and instructional design in the quest towards electronic assessment of web-based textual inputs.
Computing
M.Sc. (Information Systems)