Month: June 2015

Designing Shape Memory Materials for Damping, Actuation, and Energy Applications

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Wednesday, June 24 • 1:30 PM – Biology/Physics Building (BPB), Rm. 130

Designing Shape Memory Materials for Damping, Actuation, and Energy Applications

Ying Chen

Assistant Professor of Materials Science and Engineering Rensselaer Polytechnic Institute, Troy, NY

Abstract: Shape memory alloys have the remarkable capability to switch between two “programmed” geometries upon the application and removal of stimuli such as stress, heat, or magnetic field. Their shape memory properties result from a diffusionless and crystallographically reversible martensitic phase transformation that occurs by shear. However, many polycrystalline shape memory alloys are limited by their inherent brittleness caused by severe stress concentration at grain boundaries during martensitic transformations. In this talk, I will present two strategies that we have developed to overcome this limitation. I will discuss our recent work on small scale oligocrystalline alloys with bamboo grain structures, and potential technological developments that can result from our understanding of the small-scale properties and size effects. When bulk polycrystalline structures are desirable, we design dual-phase alloys in which a ductile nontransforming second phase is precipitated along grain boundaries to cushion the grain boundaries and alleviate stress concentrations. Oligocrystalline and polycrystalline shape memory alloys with excellent shape memory properties and mechanical durability are promising for many damping, actuation, and energy applications.

Biographical Sketch: Dr. Ying Chen earned her B.S. in Materials Science and Engineering from Tsinghua University in Beijing, China in 2004 and Ph.D. in Materials Science and Engineering from MIT in 2008. She was a postdoctoral associate at the MIT Institute for Soldier Nanotechnologies from 2008 to 2010, before joining GE Global Research Center in Niskayuna, NY as a materials scientist. She worked on high temperature superalloys at GE GRC for a little over a year, and then joined the Rensselaer faculty at the end of 2011. Her research focuses on elucidating microstructure-mechanical property relationships in metallic materials using both experimental and mesoscale modeling approaches.

For additional information, please contact Prof. Michael T. Pettes at (860) 486-2855, pettes@engr.uconn.edu or Laurie Hockla at (860) 486-2189, hockla@engr.uconn.edu

Three Generations of Engineering at UConn

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When Robert Valley Sr. entered the doors of Castleman in 1946, he did not know that he was starting a legacy. Now – almost 70 years later – three members of the family have walked through those doors and graduated in 1950, 1978 and 1981. And another generation is expected to graduate in May of 2016.

This is one of the Legacy Families that the School of Engineering is trying to find and chronicle  – families that return to UConn’s School of Engineering and consider it home. (Contact information below.)

From left to right: Robert Valley Sr., Stephen Mierz, and Matt Mierz

For Robert Sr., engineering seemed natural. He had always wanted to be an engineer.  “Early on, I got into ham radios,” he said. “It  was fascinating to have a piece of block and a coil and some headphones and tune into your local radio station.” Those days of tinkering were a great time for people with an engineering bent. But today’s devices are too complex, said the Branford resident. “You can’t even take them apart and understand what’s inside. The circuitry is not accessible.”

His son, Robert Valley Jr., chief engineer with Branford-based Analytica, recently acquired by PerkinElmer, felt the same affinity for Engineering. “It just seemed to be the appropriate path,” said the man who started his own business at age 15. Bob Jr. created “Rapid Robert’s Repair Services,” during a summer vacation to fix tape recorders for SoundScriber Corp., then his father’s company. From there, the path was natural. Bob Jr. graduated from UConn with a degree in Electrical Engineering in 1978 without even discussing it with his father, the men said.

The legacy does not stop there. Robert Sr.’s daughter Diane met her future husband Stephen Mierz here at UConn. He graduated in 1981 with a Mechanical Engineering and Materials Engineering degree. Steve caught the engineering bug from his father, who did engineering work, but did not have a degree. His father encouraged Steve to pursue his degree so that he would have more career options.

Taking his father’s advice, he attended Engineering career fairs and met with Sikorsky, where he has worked ever since. He now handles forensic engineering, inspecting brakes, wheels and other parts that have failed, and figures out how each failure occurred. “At the end of the day, to be contributing to something that makes the company more successful, that’s a good feeling,” he said. “Money’s good, but I think you need to have job satisfaction that makes every day interesting and fun.”

Steve’s worn a lot of different hats at Sikorsky, and advises his son and other UConn Engineering students to be adventurous and flexible. “Be open to things at whatever company you go to,” he said. “Don’t decide that you’re going to do just one thing. Be open to possibilities. There is a lot of neat stuff that you can do, especially if you go to a big company.”

His son, Matt Mierz, who’s carrying on the family legacy at UConn, is scheduled to graduate next year with a degree in Mechanical Engineering. Matt said he and the elder engineers in his family will occasionally talk about how the field has changed, and how much the UConn Engineering School has expanded. His interest in engineering includes cars and motorcycles. “I went into it because I enjoyed it.”

The UConn School of Engineering is proud of the families making engineering a part of their family tradition.  Alumni and students who are the children, grandchildren, parents, grandparents or siblings of School of Engineering graduates are legacies.  Please keep in touch with your School and confirm your legacy status with the Director of Engineering Alumni Relations, Heidi Douglas (hdouglas@engineer.uconn.edu).  We hope to hear from you.

Electronic Transport in Topological Insulator Nanostructures

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Wednesday, June 10 • 1:30 PM – Biology/Physics Building (BPB), Rm. 130

Electronic Transport in Topological Insulator Nanostructures

Luis A. Jauregui

Postdoctoral Associate, Philip Kim Group Department of Physics, Harvard University, Cambridge, MA

Abstract: I will describe our recent transport experiments on topological insulator materials such as Bi2Te3 and BiSbTeSe2 nanoribbons (TINRs). We were able to successfully distinguish the bulk and surface carriers. The experiments have particularly revealed a list of unique transport signatures of the spin-helical, Dirac fermion topological surface states, and provide ways to access and utilize such surface states in novel topological quantum devices. Topological insulators (TI) are gapped band insulators in the bulk, but have nontrivial, “topologically protected”, spin-helical conducting states with gapless Dirac fermion dispersion on the surface. Such “topological surface states” are considered promising platforms to explore various novel physics ranging from quantum anomalous Hall effect, Majorana fermions to excitonic condensation. However, electronic transport of topological surface states in real TI materials is easily obscured by competing conduction channels that include the bulk as well as the “conventional” 2D electron gas (2DEG) formed by band bending at the surface. This is a major challenge in current experiments and device applications involving topological insulators. In this talk, I will describe our recent electron transport experiments on TI materials based on Bi2Te3 and BiSbTeSe2. We have explored ways to reduce the bulk conduction, and revealed a list of unique electronic transport signatures of the spin-helical, Dirac fermion topological surface states. In addition, we have also measured induced superconductivity in TINRs. These experiments may facilitate better access and control of TI surface states to explore the more exotic physics and applications in topological quantum devices.

Biographical Sketch: Dr. Luis Jauregui earned his B.S. in Electrical Engineering from National University of Engineering in Lima, Peru in 2007 and his Ph.D. in the area of micro and nanotechnology from the Department of Electrical and Computer Engineering at Purdue University in 2015. He was the recipient of the Intel Ph.D. fellowship for the years 2012 – 2013 and the Purdue Research Foundation Fellowships 2013 – 2015. Currently, he is a postdoctoral associate in the Department of Physics at Harvard University. His research focuses on experimental investigations of electron transport in low dimensional systems like nanowires, and two dimensional layered materials.

For additional information, please contact Prof. Michael T. Pettes at (860) 486-2855, pettes@engr.uconn.edu or Laurie Hockla at (860) 486-2189, hockla@engr.uconn.edu

Alumni, James Kane

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James Kane (Ph.D. Mechanical Engineering, ’86), associate professor of Mechanical and Aeronautical Engineering, was named professor emeritus at Clarkson University’s 122nd commencement ceremony in May.  He was honored for more than 25 years of exemplary service to the university.  In addition to his classroom instruction, Kane wrote 42 articles in professional journals and is the author of “Boundary Element Analysis, in Engineering Continuum Mechanics.” He also co-edited two academic books.

Alumni, Paul Dul

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Paul Dul (B.S. Mechanical Engineering/Materials Engineering, ‘88) joined Apcera, maker of the world’s first operating system for the hybrid cloud, as vice president of Product.  Dul brings more than 20 years of product management and leadership experience.  Previously, he was vice president of Product at Embrane and led the product management team at Andiamo Systems.  Earlier in his career, Dul headed product management for Cisco’s $3 billion Catalyst 5000 product line.  He earned masters’ degrees in engineering and management from MIT.