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Novel molecular architectures from iptycene polymersTsui, Nicholas T. (Nicholas Tang) January 2007 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007. / Includes bibliographical references (p. 201-215). / This thesis explored the incorporation of iptycenes into polymers as a means to enhance the mechanical properties. Iptycene structures were targeted because they possess a unique structural property called internal molecular free volume. When these bulky pendant groups are incorporated into the backbone of a polymer chain, they produce a novel chain architecture called molecular barbed wire. This molecular barbed wire architecture not only influences individual polymer chain dynamics but also induces lateral interactions between polymer chains through the minimization of internal molecular free volume. Work began by developing the concepts of internal molecular free volume and how to exploit its minimization. A formal definition for this property was created along with methods to identify and quantify its existence. Experimental results document the effects of introducing this property into polyesters and polycarbonates. Two specific novel inter-chain interactions were established: molecular threading and molecular interlocking. These steric interactions between polymers chains generate a non-bonded, network morphology and actively enhance the mechanical properties during deformation. / (cont.) It was demonstrated that the stiffness, strength and ductility of polymers could be enhanced simultaneously through this method. Mechanical properties were observed in tension at quasistatic deformation rates and in compression at both quasistatic and ballistic deformation rates. Improved mechanical performances were related back to structural properties through x-ray scattering experiments. Concepts of internal molecular free volume were necessary to explain the structure-property relationships observed. In addition, a prototype of enhanced polycarbonate was successfully developed for possible use in protective armor applications. This work provides a new pathway for the continued research and development in the field of ballistic protection. / by Nicholas T. Tsui. / Ph.D.
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A technical and economic evaluation of novel pH-responsive core-shell nanoparticles : delivering innovation from laboratory to marketCho, Eun Chol, M. Eng. Massachusetts Institute of Technology January 2008 (has links)
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / Vita. / Includes bibliographical references (leaves 64-69). / Many potentially powerful therapeutic strategies for the treatment of disease require the delivery of drugs into the cytosolic or nuclear compartments of cells. Members of the Irvine laboratory have developed a novel pH-responsive core-shell nanoparticle system that can achieve efficient and non-cytotoxic drug delivery into the cytosol. Another advantage is that the shell can be easily modified to bind to different types of drug agents and incorporate ligands for specific cell targeting. Experimental analysis of the newly synthesized nanoparticles with various shell structures has demonstrated that modification of the shell does not compromise their cytosolic delivery. These nanoparticles, if successful, will improve the therapeutic potential of a wide range of drugs. However, critical issues on the research side need to be resolved, and an appropriate intellectual property strategy should be initiated in the near future. Applications to siRNA delivery and vaccines have been examined in depth, as cytosolic delivery is one of the main challenges in these fields. Partnerships with large pharmaceutical companies are critical in order to acquire key patents on siRNA/antigen. Even though the market is competitive, there is a strong demand for innovative delivery platforms; provided that the overall profile of the core-shell nanoparticles is comparable to that of emerging drug delivery systems, and a strong intellectual property portfolio is developed, the Irvine technology should be able to compete in the market. After analyzing risks on the business side, including the FDA approval process, a suggested business strategy is outlined, through which value can be successfully obtained throughout the existing pharmaceutical supply chain from the novel drug delivery system. / (cont.) The Irvine technology company will develop formulations, contract manufacturers will produce the nanoparticles, and pharmaceutical companies will concentrate on clinical trials, late-stage development and sales and marketing. A case study on the liver cancer market has demonstrated that commercial development of the Irvine nanoparticles can be a financially successful endeavor. / by Eun Chol Cho. / M.Eng.
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Printed circuit board materials : an evaluation of manufacturing technologies and market requirementsNg, Lee Hong January 1990 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990. / Includes bibliographical references (leaves 190-194). / by Ng, Lee Hong. / Ph.D.
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The electrical and optical properties of doped yttrium aluminum garnetsChen, Jimmy Kuo-Wei January 1994 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1994. / Includes bibliographical references (leaves 221-226). / by Jimmy Kuo-Wei Chen. / Ph.D.
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Towards material-informed tectonicsTai, Yen-Ju Timothy January 2018 (has links)
Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2018. / Cataloged from PDF version of thesis. / Includes bibliographical references. / This thesis introduces, demonstrates, and implements a unified computational design framework for material distribution modeling that enables the production of geometrically complex, materially heterogeneous, and functionally graded objects, across scales, media, and platforms. Receiving user-defined performance mappings as input, the workflow generates and evaluates instructions for designated fabrication systems, informed by the extrinsic constraints presented by the hardware and the intrinsic characteristics embedded in the materials utilized. As a proof of concept to the generalizable approach, three novel design-to-fabrication processes within the framework are introduced with material and materialization precedents and implemented through computational and robotic platforms: implicit modeling for the fabrication of photopolymers, trajectory optimizing for the fabrication of water-based material, and toolpath planning for the fabrication of fiber-based material. Titled Material-informed Tectonics, the framework extends the domain of parametric design processes from geometry to material, expands the potential application of volumetric material modeling techniques beyond high resolution multi-material 3D printing systems, and bridges between the virtual and the physical by integrating material information into the tectonic relationship between manufactured objects and manufacturing methods; thereby outlining an approach towards a synthesis of material properties, computational design, digital fabrication, and the environment. / by Yen-Ju Timothy Tai. / S.M.
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Assessment of colloidal self-assembly for photonic crystalYip, Chan Hoe January 2006 (has links)
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2006. / Includes bibliographical references (p. 87-93). / A suspension of monodisperse colloids has an interesting property of self-assembling into a three-dimensional ordered structure. This crystalline material has attracted significant interest on the implementation of photonic crystals, which have practical applications in reflectors, filters, resonators, and waveguides. In this thesis, self-assembly of colloidal crystals and photonic crystal technologies are reviewed. Potential colloidal photonic and non-photonic devices were presented and their values/limitations were discussed. Colloidal photonic crystals were assessed on their technical capabilities, growth techniques and fabrication cost. In this assessment, the bulk colloidal photonic crystals are found to be inherently robust against stacking disorder, cracks and voids. The high reflectance performance and lattice parameter tailoring are useful for implementing reflectors, optical switch and sensors. Besides, the anomalous dispersion characteristic near to the band edges or near to flat bands of the photonic band diagram is suited for superprism and light harvesting applications. Potentially, the unique characteristics of colloidal photonic crystal could be capitalized in a low cost micro-fabrication model. Finally, the study has shown that it is more technically and commercially viable to implement bulk colloidal photonic crystal applications rather than lithographically-defined types. / by Chan Hoe Yip. / M.Eng.
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Development of bi-layer mineralized bone and cartilage regeneration templateOtt, Cassandra Holzgartner January 2005 (has links)
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005. / Includes bibliographical references (leaves 86-88). / Porous collagen-glycosaminoglycan (CG) scaffolds have been studied extensively and proven to be capable of tissue regeneration in vivo for applications including skin regeneration templates, hollow nerve guides and conjunctiva regeneration. While the current CG scaffold has been thoroughly examined both mechanically and clinically, it has yet to prove appropriate for load- bearing applications. This study will investigate the mechanical properties of a mineralized CG scaffold and its application potential in a load-bearing environment. Through the introduction of calcium-phosphate mineral into the standard CG formulation the matrix analog will be available for bone regeneration. Utilizing a patented triple co-precipitation technique developed at Massachusetts Institute of Technology and Cambridge University, a homogeneous mineralized scaffold will be manufactured. Comparison to healthy trabecular bone as well as the selection of the most appropriate extracellular matrix analog will be presented. The key to commercial success is the introduction of a bi-layer bone and cartilage regeneration template to address concerns and difficulties in cartilage repair today. This dual combination is termed a layered osteochondral scaffold. / (cont.) The commercial viability of this product as well as the company founded on its inception, OrthoCaP, Inc., is delivered as a start-up venture over the next eight to ten years. With several key patents already filed, an extensive patent search was completed to establish leading competitors and technology in the marketplace. Although still in the primary phases of development, short-term profitability can be seen through licensing the technology to larger more secure firms. Long-term profitability is realized through a more scientific approach of broadening the technology to other areas of tissue regeneration and modifying the mechanical and material characteristics associated with collagen based templates. / by Cassandra Holzgartner Ott. / M.Eng.
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Understanding the economics and material platform of bidirectional transceiver for plastic optical fiberGusho, Genta January 2005 (has links)
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005. / Includes bibliographical references (leaves 74-76). / Limitations of electrical wires result in distortion and dispersion of the signal for long distances. That have emerged optical communication as the only way of communication for long distances. For medium distances optics can support the high data rates required by the latest applications. Optical networks are becoming the dominant transmission medium as the data rate required by different applications increases. The bottleneck for implementing optical instead of electric networks for medium distances, like local area network, is the cost of the optical components and the cost of replacing the existing copper network. This thesis will discuss the possible cost benefits that come from the use of different materials like plastic optical fiber instead of silica fiber or Si, Si/Ge instead of InP or GaAs for the transceiver as well as the trade offs between the performance and cost when discrete transceiver is replaced by the monolithically integrated transceiver, by using a process based cost model. / by Genta (Meco) Gusho. / M.Eng.
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The effect of strain and orientation on Inx̳Ga₁₋x̳As layers grown by molecular beam epitaxyElcess, Kimberley January 1988 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1988. / On t.p. all "x̳" is subscript. / Includes bibliographical references. / Kimberley Elcess. / Ph.D.
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Technology assessment and feasibility study of high-throughput single cell force spectroscopyCheng, He, M. Eng. Massachusetts Institute of Technology January 2010 (has links)
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 72-83). / In the last decade, the field of single cell mechanics has emerged with the development of high resolution experimental and computational methods, providing significant amount of information about individual cells instead of the averaged characteristics provided by classical assays from large populations of cells. These single cell mechanical properties correlate closely with the intracellular organelle arrangement and organization, which are determined by load bearing cytoskeleton network comprised of biommolecules. This thesis will assess the feasibility of a high throughput single cell force spectroscopy using an atomic force microscopy (AFM)-based platform. A conventional AFM set-up employs a single cantilever probe for force measurement by using laser to detect the deflection of the cantilever structure, and usually can only handle one cell at a time. To improve the throughput of the device, a modified scheme to make use of cantilever based array is proposed and studied in this project. In addition, to complement the use of AFM array, a novel cell chip design is also presented for the fine positioning of cells in coordination with AFM cantilevers. The advantages and challenges of the system are analyzed too. To assess the feasibility of developing this technology, the commercialization possibility is discussed with intellectual property research, market analysis, cost modeling and supply chain positioning. Conclusion about this technology and its market prospect is drawn at the end of the thesis. / by He Cheng. / M.Eng.
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