MENG 471/473 Projects - 2017

In MENG 471/473, students work on independent projects that cover a wide range of topics, from traditional mechanical engineering topics (e.g., mechanical device design, fluid flow, and materials analysis) to interdisciplinary topics at the interface between mechanical engineering and other branches of engineering such as biomedical, chemical, electrical, or environmental engineering. Under the supervision of faculty advisers, students investigate physical phenomena through experimental measurement and/or numerical simulation, and they design and construct functioning prototypes to solve engineering problems. The majority of the faculty advisers come from within the mechanical engineering department, with the remaining advisers distributed across the University (and occasionally outside the University). Funding for projects is generously provided by the Yale SEAS Dean's Office and, in some cases, through the faculty advisers. The students were asked to write the following short summaries two-thirds of the way through the semester, when they still had a few weeks to go on their projects. All projects are represented here, except for those that cannot be publicized due to information of a proprietary nature.

Experimental cardiac containment system circuitry

Aydin Akyol
Adviser: Prof. Stuart Campbell, Biomedical Engineering

The human heart is an incredibly intricate system of living cells that must continuously operate throughout an individual's life. Like all living cells, however, cardiac cells can be diseased or adversely affected by drugs in unexpected ways. To understand and prevent both disease and adverse effects, the Yale Integrative Cardiac Biomechanics Laboratory studies the dynamics of the heart-contraction event. However, there are some challenges to studying living, beating heart tissue, namely providing the cells with well-controlled and well-measured physiological conditions. This project seeks to integrate the functionalities necessary for cardiac tissue experimentation through the use of a specialized printed circuit board (PCB) design. Using interdisciplinary computer aided engineering, we hope to develop a PCB-based system that improves the quality and functionality of current experimental procedure. However, this system is not only designed with current experimentation in mind. This PCB-based system, once completed, will enable the future development of high-throughput experimentation for cardiac tissue. Such advancements in experimentation will empower research that may one day be used to treat disease.

Segmenting melanoma nuclei in order to collect cellular dynamics data

Brian Beitler
Adviser: Prof. Corey O’Hern, Mechanical Engineering and Materials Science

Understanding how cells grow and move is vital for a wide range of biological fields, from artificial tissue creation to understanding cancer growth and metastasis. In order to create accurate models of cell growth, it is necessary to collect information about real cell growth. We began with a three-dimensional video of melanoma cell nuclei and T-cells in order to collect information about how the melanoma nuclei grow and move. We took a single two-dimensional slice of the video from a single time point and developed an image processing program in Matlab. The melanoma nuclei were dyed red and the T-cells were dyed green, so this program first isolates the melanoma nuclei by filtering the image by color. Then the program segments each nucleus through the creation of borders by looking for image contrast. Finally, the program uses a size filter to display only individual nuclei. The final image displays only individual melanoma nuclei, and each nucleus has a defined area. This program, once finalized, could be used to collect information in order to validate existing models of cell growth.

Kinetic chair: Design and construction

Victoria Ereskina
Advisers: Dr. Timothy Newton, Architecture and Prof. Corey O’Hern, Mechanical Engineering and Materials Science

As sitting becomes more dominant in jobs and leisure, there are fewer opportunities to use and maintain muscles, bones, and connective tissue, particularly in the spine. The purpose of this project is to study how the spine can maintain its natural flexibility and curvature and use this information to develop a workstation that provides a healthier alternative to traditional chairs and standing desks. The prototype is a kinetic chair suited for a standing desk with a freely pivoting seat to engage the lower back muscles and core. Research suggests that an angle of 135° between the femur bone and the vertical is the ideal for preventing slouching, while still distributing some body load from the feet to the seat. Observing 60 random testers showed agreement with our research; the closer this angle was to 90°, the more a person tended to slouch. To maintain this angle among users of various heights, the footrest needs to have a mechanism that moves its pivot axis up and down. SolidWorks was used to study the motion and stress, and to optimize. By the end of the semester, the goal is to have a professional-looking piece of furniture that allows for a femur-spine angle of 135° ± 5°.

Security and applications in RFID technology

Timothy Foldy-Porto
Advisers: Dr. Larry Wilen and Prof. Corey O’Hern, Mechanical Engineering and Materials Science

Radio-Frequency Identification (RFID) technology has proliferated in the past twenty years: it is currently employed in a variety of industries, ranging from commerce, to transportation logistics, to infrastructure management and protection. Through our research, we examined the security and communication protocols employed by current radio-frequency systems, such as everyday ID badge scanners, and we developed potential applications of this technology. By building a proprietary RFID reader and writer, we have been able to observe security flaws in the encoding and transmission processes used by modern RFID systems. For example, we were able to receive, decode, and emulate most standard RFID badges with off-the-shelf hardware and no decryption. We are using this information as a starting point to create a more advanced algorithm by which the ID cards’ data will be encrypted. To do this, we will use embedded pseudo-random number generation in addition to the existing ID infrastructure to implement a new dual-authentication factor, which will verify both the user’s identity as well as the validity of their card. This research could potentially have ramifications for all organizations currently using RFID to secure their premises, such as universities and companies.

Theatrical LED floor

Sydney Garick
Advisers: Dr. Larry Wilen and Prof. Corey O’Hern, Mechanical Engineering and Materials Science

Fun Home tells the story of lesbian cartoonist Alison Bechdel as she grapples with memories of her closeted father and comes to terms with her own sexuality. In order to create the intimate atmosphere the show requires the audience will be seated in a thrust configuration, where smaller seating banks are used on three sides of the stage rather just on one side. This seating configuration presents unique challenges for designers because the use of traditional set pieces would block sight lines for the audience. To solve this problem we have designed an LED floor, which will be made of wood with patterns of painted Plexiglas laid into it. LEDs will shine through the Plexiglas to create images from below. So far we have designed the Plexiglas layout and used SolidWorks analysis to ensure the floor will be strong enough for actors to stand on. We have also determined the light distribution pattern of the LEDs in order to position the lights to maximize their brightness without showing individual pixels. For the rest of the semester we will work on building the full floor as well as the Arduino system that will control the LEDs remotely from the tech booth.

EZ ICE TM: Reducing component weight using topology optimization

Dylan Gastel
Advisers: Dr. Ahmet Becene, UTC Aerospace Systems and Prof. Corey O’Hern, Mechanical Engineering and Materials Science

EZ ICE TM, a Yale startup, has created The 60 Minute Backyard Rink TM, the only backyard ice skating rink that can be assembled in under an hour, with no tools, and on any surface. EZ ICE’s novel and patent-pending technology provides an entire kit that snaps together with ease — saving users dozens to hundreds of hours of backbreaking labor and frostbite compared with alternative construction methods. The aim of this project is to minimize the weight of the rink’s components such that the rink can still support the 280 pounds of outward force exerted by the water and ice, and so that it can still be manufactured using simple side-action molds without any undercuts. We have used topology optimization software to minimize material usage based on these constraints. Topology optimization optimizes material distribution within a given design space for a given set of loads and boundary conditions such that the resulting design meets prescribed performance targets. 

Printed circuit board-integrated inductive force-sensing module

Naoka Gunawardena
Advisers: Dr. Joe Zinter and Prof. Corey O’Hern, Mechanical Engineering and Materials Science

Load cells are sensors that are commonly used to relate an applied force to a change in resistance or capacitance, but they tend to be bulky, expensive, and difficult to calibrate. At Wellinks, a company that creates sensor technologies for orthotics and prosthetics, our team has been developing a novel inductive force-sensing module that has implications of improved size, cost, and accuracy. Inductive sensors are rarely used to measure force, but our work has shown that it is possible to correlate changes in inductance with a change in applied load. The sensing module is a printed circuit board (PCB) that consists of onboard memory for calibration data, an inductance-to-digital converter chip, a reference clock, and an inductive coil which takes the form of copper traces directly etched into the PCB. By the end of the semester, we hope to test modules of four different designs and explore methods of electromagnetic interference shielding in order to best optimize the signal for various force-sensing applications. This technology can be integrated into wearable medical devices, for example, to measure strap tension with the goal of monitoring proper wear of an orthotic brace.

Designing a physical foot model with tunable stiffness

Claire Huebner
Adviser: Prof. Madhusudhan Venkadesan, Mechanical Engineering and Materials Science

The cutting edge of prosthetic research combines advances in electronics, materials science, and biology to provide a better quality of life for amputees. However, these advanced prosthetics are often not feasible in developing areas as they can be expensive and difficult to maintain. The goal of this project is to create a physical model, for eventual use in these low-cost prosthetics, which mimics human foot function focused on the theory of transverse arch curvature. Work has been previously done by the Yale Biomechanics and Control Lab to show that the curvature of the foot’s transverse arch is the main contributor to its stiffness. When the tarsal bones, whose misalignment form the transverse arch, are packed more tightly, the whole foot becomes stiffer. Our design employs a cabling system whose tensioning will allow for alteration in tarsal packing in order to change overall foot stiffness. So far, we have completed our first prototype, using a combination of 3D printing and polymer molding techniques. These results have been used to inform decisions for a second prototype (see image), which is currently in fabrication. Looking forward, we plan to finish the design for the tensioning mechanism and complete fabrication for the final prototype.

Analysis and optimization of a Stewart platform-inspired robotic hand

Connor McCann
Adviser: Prof. Aaron Dollar, Mechanical Engineering and Materials Science

In the field of robotic grasping, there have been many efforts to mimic the structure of the human hand with the aim of replicating its dexterity and reliability in a robotic system. That said, no current robotic hand has ever been able to robustly duplicate the level of performance found in humans. This can largely be attributed to the high mechanical complexity of the human hand, which can be difficult to translate into a robot. In our prior research, we explored an alternate design approach, drawing inspiration from a far simpler mechanism known as a Stewart platform. The novel hand we developed was able to perform far more dexterous motions than existing hand designs, despite having a simpler mechanical structure. In the current work, we now seek to optimize the performance of this hand, building on our initial work to model its behavior and determine ways to modify the design to achieve the highest dexterity possible. Eventually, by introducing a novel design approach for robotic hands, this work will lay the necessary groundwork to improve hand performance across multiple robotic disciplines, pushing the boundaries of robotic hand capabilities.

Designing a tenodesis thrower

Lucinda Peng
Adviser: Prof. Madhusudhan Venkadesan, Mechanical Engineering and Materials Science

The ability to throw accurately at high speeds is unique to humans. We propose that this ability comes from the coupling of wrist and finger angles through the tenodesis effect. There are tendons running along both sides of the wrist, whose stiffness is thought to be a factor in determining the strength of coupling. Theoretically, the optimal stiffness would be the least stiff tendon that still allows for accurate aim, so that we can maximize the window of time and angle at which the ball can exit for an accurate throw. We are designing a throwing device to model the wrist and hand, depicted in the image. Next semester, we will test the accuracy of throws depending on the strength of coupling between wrist and finger angles. We are also interested in the differences of distribution of power output and joint movement in maximal and submaximal speed throwing. This project could advance our understanding of the mechanics behind throwing, and it has implications for the design of high-speed throwing robots.

Development and evaluation of iron-sulfur flow batteries

Alex Tang
Adviser: Prof. André Taylor, Chemical and Environmental Engineering

The next steps in securing a sustainable energy future will likely come from improvements to energy storage solutions. Renewable energy technologies such as solar and wind rely on batteries to alleviate their intermittency and grid parity issues. However, conventional lithium-ion batteries are suboptimal for such large-scale energy storage needs. Instead, flow batteries store energy in liquid electrolyte form and utilize the inherent electronegativity differences between solutions to develop an electric current. Liquid solutions tend to be relatively inexpensive to store, which would make flow batteries cheaper for large-scale energy storage than current lithium-ion batteries. This project will investigate the viability of iron and sulfur solutions as electrolytes for a flow battery and subsequently the viability of such a flow battery as energy storage for renewable power generators. Thus far, a scaled model battery is being assembled. The current design shown in the image consists of two power sources, two pumps, two sealed bottles for electrolyte storage, and a specialized chemical cell incorporating a modified Nafion membrane. By the end of the semester, we hope to evaluate the energy performance of the flow battery in order to optimize the design for future applications.

To move or not to move: Principal curvatures of articular surfaces

Aaron West
Adviser: Prof. Madhusudhan Venkadesan, Mechanical Engineering and Materials Science

When recreating species that no longer exist, anatomists and paleontologists aim to put together bone structures and try to determine how that species may have moved. We aim to quantify their work by producing a geometric theory that can determine how a limb moves based on the surface geometry at its joint. To do so, we will design an experiment that will allow us to predict movement capabilities at a joint based purely on the principal curvatures of the articular surfaces. Our experiment will hold one end of a chicken bone connected to a load cell. On the other end, the chicken bone will have a small displacement applied to it, and based on statics, the stiffness of the joint in that particular orientation can be determined. This process will be repeated after the joint is rotated 5 degrees until we have the stiffness for all 360 degrees. So far, we have finalized a prototype for the design and determined which instruments will be used to make small, accurate rotations and displacements. By comparing our data and CT scans of surface geometry at the joint to the data of in vivo motion, a geometric theory can be produced and validated.