Student News

2012 Project Presentation Day

April 19, 2012
1st Floor, Washburn 107 & 108

Project Presentation Photo Gallery

Development of Visual Humidity Indicator for 3D Printed Cores for Metal Casting

Students: Tiffany Chau, Paul Finn, Jesse Ouellette
Advisors: D. Apelian, N. Kazantzis

During metal casting, cores are emplaced in the mold. Cores with high moisture content give rise to porosity in the cast part therefore impairing quality. The project goal was to create a visual humidity indicator to determine moisture content of a 3D printed core. We accomplished this by successfully incorporating phenolphthalein into sand based powder in the printing process. The success of our project will optimize digital manufacturing and metal casting by ensuring high quality cast products and improved productivity.

Adhesion of Silver Nanoparticles

Students: Robert Cakounes, Michael Judelson
Advisors: D. Brodeur (CHE), N. Burnham (PH), J. Liang
Sponser: Grant-In-Aid from the National Academy of Sciences, asministered by Sigma Xi, The Scientific Research Society

To better understand the life-cycle of a nanoparticle it is important to study how nanoparticles adhere to substrates. This project implemented various removal techniques to study the adhesion strength of silver nanoparticles to carbon substrates with various surface chemistries. TEM characterized the size, distribution, and agglomeration of the nanoparticles. IR confirmed the surface chemistry. This project developed a semi-quantitative method to determine adhesion strength. A brush is run along the surface and the change in concentration is measured using AAS. Our project shows a correlation between the force of adhesion and the surface chemistry.

Synthesis and Characterization of Tin Oxide-Supported Plati-num for Cathode Catalysts of Direct Methanol Fuel Cells

Students: Manish Chawla, Tony Chou, Kevin McCarthy, Xi Geng
Advisors: R. Datta (ChE), J Liang

It is imperative to reduce society’s reliance upon the limited sup-ply of fossil fuels. Direct methanol fuel cells (DMFC) possess immense potential as an alternative to current energy generation methods, especially in portable applications because of their high energy density, low operating temperature, and ease of handling. Several obstacles encountered by contemporary carbon-supported catalysts, however, are preventing widespread adoption of the technology, including prohibitive materials cost and relatively abbreviated life cycles due in part to inefficient Pt-catalyst loading and cathode degradation resulting from methanol crossover. The following research investigated the potential of tin oxide as a DMFC electrocatalyst support due to metal oxides’ high electrical conductivity, good corrosion resistance, and resistance to the effects of methanol crossover. In this paper, two synthesis methods to prepare tin oxide-supported platinum are reported: the impregnation process and the colloidal process, relying primarily on ethylene glycol as the reduction solvent. Platinum particle size, loading, and surface distribution on the tin oxide support were characterized by TEM, SEM, and XRD, while its electrochemical properties were determined by electrochemical tests. It’s physical and electrochemical properties were compared with conventional Vul-can XC-72 carbon black-supported platinum.

Material and Design Optimization for an Aluminium Bike Frame

Students: Forrest Dwyer, Adrian Shaw, Rick Tombarelli
Advisors: D. Lados

Fatigue is a prominent failure mechanism for mountain bike frames, and can lead to serious accidents, costly recalls, and poor product image for bicycle frame manufacturers. The team collaborated with a local bike company, in the process of developing a new 6061-T6 aluminum mountain bike, to investigate the fatigue behavior of the new frame and optimize the material/heat treatment and frame design. The fatigue testing was done inhouse using a test rig specifically built for this project according to the ASTM standard F2711-08 for horizontal loading. A solid model of the frame was created and a finite element analysis (FEA) was conducted using the ASTM standard as a guide, with appropriate mechanical properties for various sections of the bike and the joining welds. The FEA model enabled the team to predict fatigue failure locations and cycles to failure, and was further validated using the experimental fatigue testing results obtained from the prototype frames. On the physical frames tested, thorough fracto-graphic examinations were conducted to identify the fatigue crack initiation locations and crack propagation mechanisms using optical and scanning electron microscopy. To complete the project, systematic studies were performed to optimize the frame’s design, materials and heat treatment for improved fatigue resistance.

Synthesis of Silicate Based Lithium-Ion Battery Cathodes

Students: Andrew Boucher, Michael Ducey, Nathan McNeff
Advisors: J. Liang, D. DiBiasio (ChE)

As technology advances, the need for alternative sources of energy arises. Batteries have been studied by many different research groups as a proper way to power everything from small devices such as cell phones to large units such as cars and factory machinery. Specifically, lithium-ion batteries have been vigorously studied due to their numerous benefits such as high energy density, high voltage and a low self-discharge rate. Thin-film lithium-ion batteries have been researched, but not many successful prototypes have been developed. These prototypes have incorporated active materials such as LiCoO2, LiMn2O4 and Li2MSiO4 (where M=Mn, Fe, Ni, etc.). Based on prior research, many of these materials vary in properties such as theoretical capacity, conductivity and cycling life. Lithium silicates, with two lithium atoms in each molecule have been proposed as candidates with higher theoretical capacity. Pure phase compounds with a general formula of Li2MSiO4 (M=Mn, Fe, Co) have been tested and each has manifested unique drawbacks. In this project we want to test the hypothesis that Li2MSiO4 with mixed M of Fe and Mn might provide superior performance to the pure phases as observed in the case of the layered LiMO2 cathodes. We first studied the synthesis of Li2FexMn1-xSiO4 through a sol gel process. Li2FexMn1-xSiO4 materials with different Mn to Fe ratios have been synthesized. Carbon coating was used to increase the active material’s conductivity. We then characterized the composites through an array of tests, including XRD, SEM and coin-cell battery testing. The results are discussed in this presentation.

Fire Fighter PPE

Students: Ricardo Belmontes, Barbara Hall
Advisors: K. Notarianni (FPE)

The objective of this Major Qualifying Project was to determine the thermal limit of a polycarbonate facemask material used by firefighters and compare it to an alternative high temperature material, polyethersulfone. The effects of repeated heat stresses on Self Contained Breathing Apparatus facemask failure were studied. A series of tests were conducted at the product level on polycarbonate and polyethersulfone samples by exposing both materials to convective and radiant heat sources. The final test recorded the time to failure of a new and used polycarbonate facemask that had extensive use by firefighters in training exercises. The results of the tests were compiled and presented to the National Fire Protection Association 1981, Standard for Open Circuit Self-Contained Breathing Apparatus for Use in Emergency Services, Technical Committee. These results may be used in the process of updating the current standard for the 2013 edition.

ACES characterization of damping in micro-beam resonators

Students: Xiuping Chen, Vu Nguyen, Jason Parker
Advisors: R. Pryputniewicz

Recent advances in microelectromechanical systems (MEMS) technology have led to development of a multitude of new sensors and their corresponding applications. Great many of these sensors (e.g., microgyroscopes, accelerometers, biological, chemical, etc.) rely on vibrations of either sensing elements or elastic suspensions that resonate. Regardless of their applications, sensors are always designed to provide the most sensitive responses to the signals they are developed to detect and/or monitor. One way to describe this sensitivity is to use the Quality factor (Q-factor). Most recent experimental evidence indicates that as physical sizes of sensors decrease (especially because of advances in fabrication by surface micromachining) the corresponding Q-factors increase. This project develops a preliminary model of Q-factors of MEMS resonators using Analytical, Computational, and Experimental Solutions (ACES) methodology to investigate the effects of various damping mechanisms on the Qfactor of micro mechanical resonators. We have focused on the contributions of air damping, thermoelastic damping (TED), and surface damping to the Q-factor. Laser Doppler Vi-brometry (LDV) and Michelson Interferometry were used to characterize the damping of tipless atomic force microscopy (AFM) probes through ring down tests. Tests were performed at various levels of vacuum with different beam geometries and coatings. COMSOL was used to model the TED as well as resonance characteristics of the beams and the computational results were compared to analytical and experimental results. It was found that as surface area to volume ratio increases beyond approximately 1 μm-1, surface damping becomes the dominant damping mechanism. Additionally air damping was significant at a vacuum level greater than approximately 0.1 μbar. It was also found that the surface damping was much greater with a 28 nm Au-Pd coating as compared to a 30 nm Al coating and damping increased with coating thickness. Finally, the dissipation term in the analytical approximation of surface damping was calculated for the above coatings.

Dynamic Evaluation of Forces during Mastication

Students: Justin McGarry, Anthony Spangenberger
Advisors: S. Shivkumar

Mastication simulators are a powerful tool for the dynamic evaluation of mechanical properties in food. A simplified reproduction of the human masticatory system is presented here to evaluate mechanical properties of foods, relevant design elements of a simulator, and the practicality of the system. The model incorporates a cam-driven linkage system moving a set of dentures, whose reaction forces are measured with strain gauges on two axes to record real-time changes in food structure that cannot be analyzed accu-rately in vivo. Experimental outcomes include texture profiles for a range of foods, comparison of the masticatory simulator to conventional food testing procedures, and evaluation of necessary de-sign criteria. Ideally it will be shown that a simulator provides superior data acquisition to both traditional mechanical testing and human experimentation at a similar or lesser cost.

Real-Time Process Monitoring and Statistical Process Control for an Automated Casting Facility

Students: Daniel Lettiere
Advisors: S. Shivkumar
Sponsers: Hitchiner Manufacturing Company

In the metal casting industry, defects increase cost of production, expand required labor hours, and decrease overall productivity. Better understanding of process variables allows for successful reduction of defects. Utilizing real-time data logging technology and statistical process control software creates the framework for an effective process monitoring system. To establish a correlation between mold temperature and casting defects, a unique data logging system, capable of withstanding high temperatures, was designed. The beneficial results of this project will not only impact the process today, but will help improve future innovations in the industry.

April 19, 2012

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