Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

The capability to easily and inexpensively fabricate microfluidic devices with negligible dependence on specialized laboratory equipment continues to be one of the primary forces driving the widespread use of plastic-based devices. These devices are typically produced as replicas of a rigid mold or master incorporating a negative image of the desired structures. The negative image is typically constructed from either thick photoresists or etched silicon substrates using conventional photolithographic fabrication processes. While these micromachining techniques are effective in constructing masters with micron-sized features, the need to produce masters rapidly in order to design, fabricate, and test microfluidic devices, is a major challenge in microfluidic technology. In this research, we use inexpensive photosensitized copper clad circuit board substrates to produce master molds using conventional printed circuit technology. The techniques provide the benefits of parallel fabrication associated with photolithography without the need for cleanroom facilities, thereby offering a degree of speed and simplicity that allows microfluidic master molds to be constructed in approximately 30 minutes in any laboratory. These techniques are used to produce a variety of microfluidic channel networks using PDMS (polydimethylsiloxane) and melt-processable plastic materials.

The capability to easily and inexpensively fabricate microfluidic devices with negligible dependence on specialized laboratory equipment continues to be one of the primary forces driving the widespread use of plastic-based devices. These devices are typically produced as replicas of a rigid mold or master incorporating a negative image of the desired structures. The negative image is typically constructed from either thick photoresists or etched silicon substrates using conventional photolithographic fabrication processes. While these micromachining techniques are effective in constructing masters with micron-sized features, the need to produce masters rapidly in order to design, fabricate, and test microfluidic devices, is a major challenge in microfluidic technology. In this research, we use inexpensive photosensitized copper clad circuit board substrates to produce master molds using conventional printed circuit technology. The techniques provide the benefits of parallel fabrication associated with photolithography without the need for cleanroom facilities, thereby offering a degree of speed and simplicity that allows microfluidic master molds to be constructed in approximately 30 minutes in any laboratory. These techniques are used to produce a variety of microfluidic channel networks using PDMS (polydimethylsiloxane) and melt-processable plastic materials.

No description available.

With the recent advancement on robotics and CAD/CAM technologies, an articulated robot has been applied as a multi-axis CNC machine for producing complex/large prototypes. However, the single-robot machining technology can only offer limited machining capability due to its limited degrees of freedom, restricted reach and inherent singular points. To overcome the problems, a dual-robot workcell has been developed. / The development of the dual-robot workcell is presented in this thesis. It consists of four main parts, namely: kinematic modelling and postprocessor development; dual-robot programme generation and its control; robot calibration; and implementation of the system. / Kinematic models were constructed to establish the analytical description for both robots in the workcell, and therefore an accurate control of positions and orientations of each robot could be achieved in the machining process. In addition, a postprocessor was successfully developed for the dual-robot workcell to achieve the integration of three major types of five-axis machining configurations. These are the tool/workpiece-tilting type, the workpiece-tilting type and the tool-tilting type. / A robot path generation module was developed to automatically generate the programmes required for both robots to machine components. Furthermore, a PC-based distributed control architecture for the dual-robot workcell was implemented to control the robots to execute concurrent motions for machining operations. The robot controllers communicated successfully with each other via the architecture / A camera-aided method was proposed for calibrating the positioning accuracy of the dual-robot workcell. The method was implemented and provided sufficiently good results for prototyping tasks, with the calibrated accuracy approaching to the robot's repeatability. / Finally, several experiments were conducted to verify the current prototyping capability of the dual-robot workcell. From the results of prototyping spherical and sculptured surfaces, the dual-robot machining shows greater advantages over single-robot machining in terms of machining productivity and quality. / The result shows that the proposed scheme is an effective approach to complement existing CNC and single-robot machining techniques for achieving rapid and flexible prototyping. / Thesis (PhD)--University of South Australia, 2004.

Thesis (Ph.D.)--Tufts University, 2000. / Adviser: Charalabos Doumanidis. Submitted to the Dept. of Mechanical Engineering. Includes bibliographical references (leaves 118-124). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 14, 2008) Includes bibliographical references.

Techn. Univ., Diss--München. / Nebent.: Optimierung des SLS.

Thesis (Ph. D.)--University of Rhode Island, 2003. / Typescript. Includes bibliographical references (leaves 228-239).

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.