Thesis (S.B. in Mechanical and Ocean Engineering)--Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013. / Cataloged from PDF version of thesis. Vita. / Includes bibliographical references (page 26). / This paper describes the techniques used to fabricate a one meter long, 1/6 scale model of a Small Waterplane Area, Twin Hull (SWATH) Unmanned Surface Vehicle (USV) that will be used primarily for dynamic seakeeping testing in the MIT Tow Tank. The model represents a design conceived by Stefano Brizzolara, which will be used for launching, recovering, and servicing Unmanned Underwater Vehicles (UUV) at sea. Construction methods included a number of rapid prototyping methods rarely used for this kind of project, including 3D printing, lasercutting, and spraypainting. The benefits and disadvantages of each of these processes will be discussed. Although there was insufficient time to conduct any tow tank tests, several data-recording techniques are reviewed which may be used by future students continuing the research of this vessel. / by John Robert DiMino. / S.B.in Mechanical and Ocean Engineering

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 27-28). / Most student projects never make the transition from a class prototype to a commercial product. This document is meant to be used as a guide by any student trying to turn an alpha prototype into a product on the market. The process is involved and there can be many challenges. There are also many approaches that might be adopted depending on the product and the goals of the inventor. This thesis begins with a discussion of technology transfer programs at three different universities and then looks into successful stories of student products. The focus then shifts to my own student product: a portable electromechanical Braille label maker that was developed in the MIT class 2.009, product engineering processes. The discussion focuses on the steps that have been taken thus far towards making the alpha prototype into a commercially available device, and discusses the steps that must be taken in the future. / by Rachel E. Tatem. / S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001. / Includes bibliographical references (p. 49-51). / The frequency-dependent response of human skin was measured, in vivo, to mechanical stimulation at a scale useful in the development of tactile displays. Sinusoidal vibration stimuli of varying frequencies and amplitudes were applied with a flat-ended 0.5 mm diameter cylindrical probe under two conditions: it was either glued to the skin or not. Both normal and tangential stimlui were applied to the skin surface in the glued case and only normal stimuli were applied in the nonglued case. The stimuli were applied to live human subjects at four body sites: the finger pad, wrist, forearm, and forehead. The force displacement response was measured and used to calculate mechanical impedance, power absorption and duty factor (an estimate of the fraction of time that the stimulator is in contact with the skin). Results showed the mechanical impedance generally increasing in magnitude with frequency and higher in magnitude for tangential stimulation than for normal stimulation. Power absorption linearly increased with frequency, and duty factor decreased with increasing frequency and amplitude. The measured properties varied widely between body sites and subjects. A mathematical model previously developed to calculate bulk and shear moduli from normal and tangential impedance data was tested against data at the four body sites. However, because the model assumed isotropy and semi-infinite thickness of the stimulated tissue, data taken did not fit the model well, especially at the finger tip. / by Timothy Thomas Diller. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000. / Includes bibliographical references (p. 111-112). / by David C. Estrada. / S.M.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2002. / Includes bibliographical references (p. 73-75). / by Alexis Christian Weber. / S.M.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 46-47). / Overhead tasks such as those frequently found in aircraft manufacturing pose health risks to the workers due to the strain imposed on the shoulders. To reduce the risk of injury, a set of supernumerary robotic limbs (SRL) were designed to perform these overhead tasks. The SRL is designed with limits in the hardware and software to protect the human and prevent collisions between robot and operator. The arms are designed to have a workspace above and in front of the head of the user free from singular configurations so the robot is free to operate where the tasks will be performed. To further protect the human, the mount that attaches the SRL to the shoulders was redesigned to be lighter and to better distribute the load. In this manner, the shoulders will become less fatigued from the static load of carrying the SRL To complete the task of positioning cables and routing them through the ceiling of an airplane, a winch end effector was designed to latch onto the fuselage arches and pull the cable through these arches. In order to control the SRL, the concept of principal components analysis was used to reduce the input space. This concept was specifically used to map the motion of the operator's hands onto the appropriate speed for the winch motor to operate. In this manner, the winch would pull the cable at the same rate that the human fed the cable. The human would then be able to control the speed of the winch simply by executing the task at whatever pace they so desired. / by Jay McKenna. / S.B.

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 53-59). / Epilepsy, which has the largest worldwide impacts among all nervous system diseases expect for stroke and dementia, is a group of long-term neurological disorders characterized by epileptic seizures. AED medications are the mainstay for epileptic seizure management. However, the existing AEDs cannot fit the needs for every patient due to the efficacy and side effect issues. In this thesis, a high-throughput system to screen new antiepileptic drug is built up. Chemically induced zebrafish larvae are used as a seizure model. The change in fishes' behavior patterns serves as an indicator of the fishes' nervous system condition. The design of the behavior data acquisition setup as well as the requirements of its components is described. A fish tracking program that tracks the locomotion variables like the head position, the tail movement and sideway orientation etc. is developed. The tracking results are treated either by simply computing the statistics of the tracking variables or implementing behavior pattern classifications. Two test datasets involving two different convulsants and one known AED are acquired and analyzed. The results coincide with the existing knowledge about the chemicals' effects on the human nerve system, which suggests the system described in this thesis is promising to help with the actual AED development. / by Yuelong Wu. / S.M.

Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (page 51). / It is desirable to measure pressure of a wave striking a vertical surface because this information can be used to determine the strength needed in the building materials of marine structures that may be struck by tall waves. These waves may be caused by storms, tsunamis, or dam breaks and can cause serious damage. This thesis presents two experiments aimed at measuring the pressure exerted by a wave. In both experiments, a series of water waves are released from a reservoir. One wave is released at a time and the waves vary in the initial height of water in the reservoir. In the first experiment, pressure is calculated using a force sensor to determine the force on a paddle and a high-speed camera to determine the contact area. It was found that wave pressure increases as the initial height increases. The pressures ranged from 5+/-2kPa at 25+/-1cm initial water height and 12+/-2kPa at 45+/-1cm initial water height. In the second experiment, pressure is measured at multiple vertical and horizontal locations on a vertical cantilevered plate. A sensor located in the middle of the plate horizontally and 1.25in from the bottom recorded the highest maximum pressure for all trials. The pressures from this sensor for this experiment ranged from 1.6+/-0.1kPa at 20+/-1cm initial water height and 7.4+/-.4kPa at 45+/-1cm initial water height. / by Anne M. LaBine. / S.B.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (leaves 101-103). / Online optimal trajectory planning is required in the control of humanoid robots, advanced prostheses, and impaired human limbs via functional neuromuscular stimulation . Optimization problems that involve complex, high degree of freedom simulations of the musculoskeletal system require extensive computational effort to solve. A methodology for generating optimal gait patterns in an online and computationally efficient manner is needed. It is the goal of this thesis to work towards the development of biologic performance criteria that can be utilized in finding solutions to reduced order walking optimization problems. Toward the development of biologically realistic performance criteria, human subjects were inertially-perturbed and the reorganization of gait quantitatively measured. Ten subjects walked at a self-selected speed with and without a 5 kg mass attached to the right ankle. Kinetic and kinematic data were collected for the weighted and unweighted conditions using ground force platforms and a multi-camera infrared tracking system, respectively. A 16 segment model of the body was built for each subject and a variety of kinematic, kinetic, and total system parameters calculated throughout the gait cycle. / (cont.) Additionally, the normal kinematic dataset was analyzed with a 5 kg mass virtually placed on the right ankle. The virtual mass dataset served as a known suboptimal solution as a basis for comparison. A Wilcoxon rank sign test was performed, and the ankle-weighted dataset was compared to normal. There were no significant changes in stride frequency, step length, stride length, or self-selected walking speed between the weighted and unweighted walking conditions. There were significant deviations in the kinematics of the right leg, but most were generally small with the exception of a decrease in maximum flexion angle of the affected leg during swing. In comparison to the virtual mass case to the true weighted case, it was determined that the reorganization of gait yields an increase in gait efficiency, a decrease in work to move the body center of mass, and a general reduction in reaction torque of the affected leg. It is suggested that the biologic performance objective consists of some function comprising of the energetic costs to move the body center of mass, gait efficiency, and joint reaction torques. / by Benjamin John Swilling. / S.M.

Thesis (M. Eng. in Manufacturing)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 80). / by Jun Bum Lee. / M.Eng.in Manufacturing