Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997. / Includes bibliographical references (p. 109-110). / by Haissam A. Haidar. / Ph.D.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 92). / The Skywalker as found in MIT's Newman lab is a device that performs Body Weight Support Treadmill Therapy a form of walking therapy for recovering stroke patients. During clinical trials conducted in the fall of 2014, it became evident that the design of the Skywalker did not fully address how patients would mount and dismount the Skywalker. The current iteration of the design requires the patients to use stairs to mount and dismount the system. Given the gait impairment of the patients using the system it is evident that an alternative must be provided for the stairs in order to make the Skywalker accessible to severe stroke patients. The following thesis explores the idea of using a lead-screw driven platform lift to solve the problem. While the solution developed during the design process is a viable option, the high material cost disqualifies the solution discussed in this thesis as a viable option for implementation in the Skywalker system. The author recommends that alternative solutions such as ramps may provide a more low-cost and effective option for mounting and dismounting the Skywalker. / by Simon A. Okaine. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1995. / Vita. / Includes bibliographical references (p. 215-223). / by Gregory Thomas Martin. / Ph.D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 243-247). / Every day, about 20% of the clean water produced in the world is lost due to pipe leaks. Due to limitations in available technologies, most of the leaks are either not found, or found too late. Every year, there are 240,000 water pipe breaks in the US, and many of them cause sinkholes and other severe damage to the infrastructure. Water utilities need methods for detecting and locating such leaks before they become big breaks, so that they can perform preventative maintenance. This is to save water and protect infrastructure. This thesis presents the design, analysis, fabrication and field test validations of such a solution. I developed soft robots for early detection of leaks in water pipes when the water service is on. This work introduces four key contributions: (1) Design, fabrication and field validations of soft robots for operating water pipes (2) Design, fabrication and field validations of a tactile sensor for detecting leaks in operating water pipes (3) Differentiate leaks from false positives with a low-cost soft bending angle sensor (4) A practical, minimalism approach to the in-pipe localization, specifically for soft robots. The results are validated in simulations, lab, and field experiments. Those sensors and robots are designed to be low-cost and scalable. They are fabricated with ordinary material with ordinary tools. It is a sub-500-dollar solution to a multi-billion-dollar water and infrastructure problem. / by You Wu. / Ph. D.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 69-71). / Striking a ball with an implement occurs often in sports. Athletes are given a large variety of options to choose from when they select their implements. The motivation for this study was the need for a simple method that athletes can use to choose the implement that will allow them to perform their best. The specific focus of this work is identifying the weight properties an implement should have in order to have the most "powerful" shot. The "power" of a shot is measured by how fast the athlete is able to make the ball move after hitting it (the outgoing ball speed). The particular weight property of interest is the implement's mass moment of inertia about an axis through its handle. Five simple models for how the implement's moment of inertia affect the outgoing ball speed are developed and compared, primarily in a field hockey case study. A new model based on the physiology of muscles proves to be more successful in capturing the behavior observed in real striking of sports balls and is the primary contribution of this study. Overall, the models predict that heavier implements than are currently used would produce more powerful shots. This result is reasonable, as implement's are rarely selected with the sole purpose of hitting power shots. Additional objectives should be incorporated into the model to more broadly aid in an athlete's implement selection process. / by Sarah Claire Fay. / S.M.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1993. / Includes bibliographical references (p. 129-133). / by Viswanathan Krishnan. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Bibliography: leaves 126-130. / by Mary Cunningham Boyce. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1984. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Jung-Hoon Chun. / Ph.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, February 2005. / Includes bibliographical references (p. 32-33). / Peptide is a b iomaterial with great promise in tissue engineering because it has known to be capable of self-assembly. Also, the peptide scaffolds can support neuronal cell attachment, differentiation, and neuron outgrowth. They might therefore p lay a role as substrate for functional synapse formation between neurons. One important feature of peptide gel is that its modulus can modulate cell motility in combination with the observation that streptavidin and biotin can be used to increase the peptide gel's modulus as measured by rheometery that raises the prospect of controlling cell function by control of matrix physical properties. Atomic force microscope (AFM) was used to reveal the mechanism of modulus change at the nano and microscales. AFM images show that as the amount of biotinylated peptide increases, self-assembly effect is impeded and there are more but smaller aggregates. Streptavidin tethers to regular peptide as well as biotinylated peptide. Also, streptavidin and biotin can cross-link peptide fibrils. These AFM results can explain the increased modulus found by rheometry. To better describe the growth from individual monomers to filaments, and to exert a measure of control over the nature of network or characteristics of individual filaments requires a better fundamental understanding of the process of filament formation. Therefore, we observed the growth of RAD16- II by self-assembly in order to gain better understanding of process by which filaments grow. Through a combination of AFM and dynamic light scattering we are able to characterize peptide growth quickly and easily. Dynamic light scattering (DLS) provides a single and convenient means to follow peptide filament growth with time. / by Woncheol Jeong. / S.M.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1994. / Includes bibliographical references (leaves 80-82). / by Nick I. Nassuphis. / M.S.