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.

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.

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.

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.

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.

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.

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.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 34). / Bamboo has received much interest recently as a construction material due to its strength, rapid growth, and abundance in developing nations such as China, India, and Brazil. The main obstacle to the widespread use of bamboo as a structural material is the lack of adequate information on the mechanical properties of bamboo. In this work, the microstructure and mechanical properties of Phyllostachis dulcis bamboo are studied to help produce a model for the mechanical properties of bamboo. Specifically, a linear relationship is established between the density of bamboo samples, which is known to vary radially, and their strength in compression. Nanoindentation of vascular bundles in various positions in bamboo samples revealed that the Young's modulus and hardness of the bundles vary in the radial direction but not around the circumference. The compressive strength of bamboo samples was found to vary from 40 to 95 MPa, while nanoindentation results show the Young's modulus of vascular bundles ranges from 15 to 18 GPa and the hardness ranges from 380 to 530 MPa. / by Michael R. Gerhardt. / S.B.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 52-56). / Bulk luminescent solar concentrators (LSC) cannot make use of Forster resonance energy transfer (FRET) due to necessarily low dye concentrations. In this thesis, we attempt to present a poly-vinylalcohol (PVA) waveguide containing dye-aggregate polystyrene nanospheres that enable FRET at concentrations below that required for the bulk LSC due to dye confinement. In the aqueous state, the maximum achieved energy transfer efficiency of the dye-doped nanoparticles was found to be 8 7% for lwt%/lwt% doping of Coumarin 1 (C1) and Coumarin 6 (C6). In the solid state, however, energy transfer is lost, reducing to 32.8% and 20.1% respectively for the C1(lwt%)/C6(lwt%) and C1(0.5wt%)/C6(lwt/ ) iterations, respectively. Presumably, the dyes leach out of the polystyrene nanospheres and into the PVA waveguide upon water evaporation during drop casting. / by Ron Rosenberg. / S.B.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / Includes bibliographical references (p. 45-48). / There has been much hype in the research and development of continuous glucose monitoring technologies, driven by the enormous and rapidly expanding glucose monitoring market and the large and growing base of diabetes patients. Continuous glucose monitoring has shown significant benefits over traditional intermittent blood glucose testing in reducing the risks of developing long-term complications associated with diabetes, by maintaining blood glucose concentrations to near-normoglycemic levels and reducing glycemic variability. In this thesis, commercially available continuous glucose monitoring systems as well as those still in development are evaluated. SWOT analysis shows that continuous glucose monitoring has a promising future, but there remain a number of challenges to be overcome, such as accuracy, sensor span, data handling, cost and reimbursement issues. It is concluded that continuous glucose monitoring will be the roadmap for future diabetes management. Ongoing technological advances in continuous glucose monitoring systems will hopefully close the loop for a fully automated artificial pancreas and develop a cure for Type I diabetes. / by Guang Li. / M.Eng.