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Dr. Rebecca Quardokus Shares Her Passion For Microscopy

By Amanda Campanaro

Rebecca Quardokus

Assistant Professor Rebecca Quardokus, Chemistry

There’s a special moment for most students when they discover what they really want to do with their major. For Rebecca Quardokus, Assistant Professor in Chemistry and associate faculty in IMS, that moment came as a junior at Grand Valley State University, Michigan, when her father sent her an article on Professor James Tour’s research at Rice University, Texas.

Dr. Quardokus, who had recently become a chemistry major, found the research fascinating. “His group had synthesized nano-sized cars with C60 fullerenes (buckyballs) for wheels, and they used scanning tunneling microscopy (STM) to image individual cars moving around on a gold surface,” Dr. Quardokus explains. “I was very excited to learn that STM, in addition to imaging, could manipulate individual atoms and molecules on the surface.” It was then she decided to attend graduate school to work with and master that “amazing technique.”

Now, Dr. Quardokus focuses her research on the engineering and reliability of molecular networks and two-dimensional materials for next-generation electronic devices. Her passion for learning STM has led her to begin a project working on developing new two-dimensional materials using surface-confined polymerization reactions.

A scanning tunneling microscope (STM) shows the tunneling junction between the tip and sample in an STM.

A scanning tunneling microscope (STM) shows the tunneling junction between the tip and sample in an STM.

“I use scanning tunneling microscopy, with its ability to measure individual atoms and molecules, to study the reactants and products,” she says.  “I will also study the charge and thermal transport properties of these materials.” Her group is hoping to tune specific properties for use in next-generation electronics.

Above, a scanning electron microscope image of an STM tip scanning a silicon nanowire. Dr. Quardokus studied the electronic properties of silicon nanowires and two-dimensional materials using a four-probe scanning tunneling microscope to measure the electronic properties and surface characteristics of positively and negatively doped silicon nanowires.

Above, a scanning electron microscope image of an STM tip scanning a silicon nanowire. Dr. Quardokus studied the electronic properties of silicon nanowires and two-dimensional materials using a four-probe scanning tunneling microscope to measure the electronic properties and surface characteristics of positively and negatively doped silicon nanowires.

Additionally, she is working on building a scanning tunneling microscope of her own. “Ultimately, I would like to build a multi-probe STM inside of a scanning electron microscope in order to analyze the reliability and functionality of nano-devices under operational conditions.”

Dr. Quardokus was always interested in math and science, and she entered college as a pre-dentistry major. However, after completing a summer of chemistry research at Grand Valley, she realized she preferred research, and decided to pursue a Ph.D. instead.

“During my graduate research at the University of Notre Dame under the direction of Dr. Alex Kandel, I used low-temperature ultra-high-vacuum scanning tunneling microscopy to study large mixed-valence iron-based inorganic molecules on gold surfaces,” she explains. “Mixed-valence compounds have interesting intramolecular charge-transfer properties.”

They found that the intramolecular charge-transfer rates depend on the geometry of the organic linker between the metal centers, and that these mixed-valence compounds retain their electronic properties when placed on a metal surface in the absence of bulk solvent.

“We also found that ferrocenecarboxylic acid forms hydrogen-bonded dimers and pentamers with longer range two-dimensional quasicrystalline ordering,” she says. This was the first example of a small molecule self-assembling into a quasicrystalline structure.

More recently, Dr. Quardokus was a National Research Council Postdoctoral Fellow at the National Institute of Standards and Technology in Boulder, Colorado. With Frank DelRio as her postdoctoral advisor, her project involved studying the electronic properties of silicon nanowires and two-dimensional materials. “I used a four-probe scanning tunneling microscope to measure the electronic properties and surface characteristics of positively and negatively doped silicon nanowires,” she says.

Above, an image of ferrocenecarboxylic acid forming hydrogen-bonded dimers and pentamers with longer range two-dimensional quasicrystalline ordering. Each small dot is an individual ferrocene carboxylic acid molecule. The pentagons are drawn around groups of 5 molecules. Shapes including pentagons, boats, diamonds, and stars show longer-range order that is analogous to P1 Penrose tiling. 

Above, an image of ferrocenecarboxylic acid forming hydrogen-bonded dimers and pentamers with longer range two-dimensional quasicrystalline ordering. Each small dot is an individual ferrocene carboxylic acid molecule. The pentagons are drawn around groups of 5 molecules. Shapes including pentagons, boats, diamonds, and stars show longer-range order that is analogous to P1 Penrose tiling.

Dr. Quardokus joined UConn’s Chemistry Department and IMS in 2016 because she believes UConn has a very strong reputation as an undergraduate teaching institution and is a world-class research institution. “I love having the opportunity to collaborate with leading scientists, and I value teaching and education because many influential professors and teachers played a large role in my personal path to success,” she says. This was very important to Dr. Quardokus, who says she had many amazing teachers and professors throughout her educational career.  “They were instrumental in shaping my career path and helping me shape and achieve my goals.”

As for her teaching style, Dr. Quardokus prefers an interactive classroom. “I want students to be thinking about and discussing problems in class. I try to show the students real-world applications for the chemistry that we’re talking about,” she explains. She hopes that students are able to internalize the concepts and use the information and problem-solving skills to tackle new challenges in the field. “I think that students positively affect research. They have a fresh perspective and ask really good questions that help push back the frontiers of science.”

Dr. Quardokus is currently recruiting graduate students to accept in Fall 2017, and she is excited to share her research program with the incoming students. “I will be installing a new low-temperature ultra-high-vacuum scanning tunneling microscope and atomic force microscope this summer,” she says. The instrument will have the capabilities to image individual atoms, molecules, and molecular bonds. “I am excited to teach students how to operate this state-of-the-art equipment allowing them to do research at the forefront of the scientific frontier.”

Among her awards are the National Research Council Postdoctoral Fellowship, 2014-2016, the Rohm and Haas Outstanding Graduate Student Award, 2013, an NSF GK-12 Graduate Fellowship, 2009-2011 and a Nieuwland Graduate Fellowship in 2007.

MSE Professor Puxian Gao Achieves Professional Milestone

MSE Professor Puxian Gao Achieves Professional Milestone

UConn Sophomore Launches Database of University Research Labs

http://dailycampus.com/stories/2017/1/24/uconn-sophomore-launches-database-of-university-research-labs

MSE Alumnus Ghanshyam Pilania awarded Humboldt Research Foundation Fellowship

http://www.lanl.gov/discover/news-stories-archive/2017/February/pilania-awarded-humboldt-foundation-fellowship.php

IMS Welcomes Dr. Tomoyasu Mani of UConn Chemistry

By Amanda Campanaro

Assistant Professor Mani

Assistant Professor Tomoyasu Mani

The Institute of Materials Science extends a warm welcome to the new member, Tomoyasu Mani, Assistant Professor in UConn’s Chemistry Department.

Dr. Mani joins IMS as associated faculty with a wealth of experience and achievements. He earned his B.S. in Biochemistry from the University of Texas at Dallas in 2009, where he worked in the laboratory of Professor A. Dean Sherry, after working as a Summer Undergraduate Research Fellow at the University of Texas at Dallas Southwestern Medical Center in 2008. Dr. Mani went on to obtain a Ph.D. in Biochemistry and Molecular Biophysics from the University of Pennsylvania under the guidance of Professor Sergei A. Vinogradov in 2013. His graduate study focused on magnetic field effects on molecular emissivity.

As a Goldhaber Fellow in the Chemistry Department at Brookhaven National Laboratory (BNL) from 2014-2016, he worked in the Electron- and Photo-Induced Processes for Molecular Energy Conversion Group directed by Dr. John R. Miller. His current research explores the application of organic and physical chemistry methods to understand the basic mechanisms of charge and energy transfer in molecular systems for applications in renewable energy and biomedical imaging technologies.

Among his recent awards are: the Blavatnik Regional Award for Young Scientists (Winner in Chemistry), 2016, which recognizes his work at Brookhaven Lab to understand the physical processes occurring in organic materials used to harness solar energy; the Gerturude and Maurice Goldhaber Distinguished Fellowship, BNL, 2014-2016; and a Speaker Award (first place) by the Society of Nuclear Medicine, “Probe Development in Molecular Imaging and Therapy” symposium at 238th American Chemical Society National Meeting, 2009, among others.

Dr. Mani enters the department with over 10 publications in various scientific journals, including the Journal of the American Chemical Society and the Journal of Physical Chemistry Letters. . He is also a member of the American Chemical Society (ACS) and the American Association for the Advancement of Science (AAAS).

IMS Welcomes Rebecca Quardokus

The Institute of Materials Science proudly welcomes a new member to its faculty of accomplished and brilliant researchers.

Rebecca QuardokusDr. Rebecca Quardokus, Ph.D., joins IMS as an assistant professor in Chemistry with significant experience to build upon. After earning her Ph.D. in chemistry at the University of Notre Dame in 2013 and completing a year-long postdoctoral term at the same department, she worked as a postdoctoral research associate at the National Institute of Standards and Technology (NIST) for two years. While at NIST, Dr. Quardokus worked as a member of the Nanoscale Reliability Group in the Applied Chemicals and Materials Division, using LT-UHV four-probe scanning tunneling microscopy (STM) to study low-dimensional materials.

Currently, her research interests lie at the intersection of materials science, chemistry, and physics, where she investigates a range of issues including the reliability of self-assembled monolayers, engineering, characterization, and reliability of two-dimensional materials, and coupling and manipulating molecular rotors. The Quardokus Research Group uses STM as the primary tool to investigate surface-confined molecular interactions and two-dimensional materials. Currently, one project characterizes the reliability of self-assembled monolayers (SAMs) after exposure to external perturbations, while another project focuses on surface-confined synthesis of two-dimensional materials.

Among Dr. Quardokus’ achievements are the Rohm and Haas Outstanding Graduate Student Award earned during her Ph.D. research, a publication titled “Green’s function modeling of response of two-dimensional materials to point probes for scanning probe microscopy,” in Physics Letters A this year and “Solving the counter ion and clocking problems in molecular QCA: Synthesis of a neutral mixed valence diferrocenyl carborane,” in Angewandte Chemie last year. Dr. Quardokus is a member of AVS: Science and Technology of Materials, Interfaces, and Processing, the American Chemical Society, and the Materials Research Society.

IMS Welcomes Dr. Martin Han

By Amanda Campanaro

Martin Han, Ph.D.The Institute of Materials Science is honored to welcome a new member to its faculty of accomplished, forward-thinking, and determined minds.

Associate Professor Martin Han earned his Ph.D. in biomedical engineering and M.S. in electrical engineering at the University of Southern California, Viterbi School of Engineering, Los Angeles, in 2003 and 2000, respectively, after completing his B.S. in electrical engineering at the University of Hawaii, Honolulu, in 1996. His Ph.D. thesis focused on the development of planar microelectrode arrays for recording and stimulation in hippocampal tissue slices for cognitive prosthesis.

Prior to joining the Biomedical Engineering Department at UConn, Dr. Han has been a staff scientist and principal investigator in the Neural Engineering Program at Huntington Medical Research Institutes (HMRI), Pasadena, CA, for thirteen years. While at HMRI, Dr. Han’s research focused on implantable microelectrode devices.

His current research interests include the development of silicon- and biodegradable-polymer-based implantable microelectrode arrays using biomicroelectromechanical systems (bio-MEMS) and hybrid microfabrication technologies for better understanding of the brain-device interface and for treating neurological disorders such as profound hearing loss, Parkinson’s disease, and spinal cord injury.

Dr. Han is a member of the IEEE Engineering in Medicine and Biology Society, Biomedical Engineering Society, and Society for Neuroscience, serves in NIH study sections, and has been awarded several NIH and DoD-DARPA grants.

High School Students Received an Introductory Course to Polymers and Materials Science

By Amanda Campanaro

Gregory Treich, center, presents an overview of basic polymer structures, linear, branched, crosslinked, and networked,  to the students (at desks). To his right stand Zachary Thatcher and Hetal Patel, undergraduate IMS students (photo taken by Kenna Ritter.)

Gregory Treich, center, presents an overview of basic polymer structures, linear, branched, crosslinked, and networked,  to the students (at desks). To his right stand Zachary Thatcher and Hetal Patel, undergraduate IMS students (UConn photo/Kenna Ritter.)

High school students are probably not thinking about how polymers and materials science are an integral part of everyday life, but it is important for young minds to be aware of the opportunities available in these ever-expanding fields. That’s why four students within the Institute of Materials Science (IMS) traveled to South Windsor High School (SWHS) December 10 to help prepare students from nearby schools for the CT Science Olympiad by introducing them to polymers and materials science concepts.

Gregory Treich, a Ph.D. student in the IMS Polymers Science program, past President/Treasurer of the Society of Plastics Engineers (SPE) and board member for the CT chapter; Zachary Thatcher, an MSE senior and member of Materials Advantage (MA); Kenna Ritter, MSE sophomore and secretary for MA, and Hetal Patel, an MSE undergraduate and member of MA presented a 90-minute introduction to SWHS students on polymers and materials science in preparation for the Science Olympiad.

The Science Olympiad is a nationwide organization dedicated to promoting science education through conducting competitive science tournaments, according to their website, and about 15,000 schools participate. Students compete in pairs or teams to accomplish various tests and tasks in areas of science. SWHS placed first in Division C during last Spring’s competition, and it looks like they hope to perform even better this coming year.

“The presentation was intended as an introduction to polymers and material science,” explains Gregory. “We highlighted specific topics that we thought had a good chance of being on their Science Olympiad exams. During and after the presentation we prompted them for questions and tried to insure they understood what we were showing them.”

Specifically, they discussed how structure, properties, processing, and performance of materials are all interwoven, and introduced general classes of metals, ceramics, polymers, and composites as well as the different types of polymers such as thermoplastic, thermoset, and elastomer.

“We covered concepts such as the major classifications of materials and their properties, atomic packing factor, fatigue and creep failure, stress strain curves, types of deformation, and microscopes,” says Kenna, in addition to Young’s modulus, Possion’s ratio, and common crystal structures, among others.

“This presentation gave them an introduction to the topics to give the students a starting point for further study as they prepare for the event,” says Gregory.

The troupe aimed to address concepts that students had trouble wrapping their young minds around in previous events, such as atomic packing factor or the way the types of bonding affect the properties of different materials. “We helped the students understand the complexity of materials science,” Kenna says.

Often, polymers and materials science are not taught in great detail in high school, which can prevent students from fully understanding the majors in college, or relevant concepts in the real world. Gregory and Kenna both believe it is important to show aspiring scientists these concepts so that majors involving them are on their radar as they apply to colleges, and to have a better understanding of the world around them.

“It’s also good to see practical applications of chemistry and physics, topics that are not often connected to “the ‘real world; in high school science classes,” adds Kenna. “Materials science is such an integral part of our lives but very few people know it exists as a separate field.”

Gregory, also a former President of SPE and currently a secondary advisor to the group, will continue to be active in SPE both regionally and with UConn however he can. Kenna plans on being involved with Materials Advantage in the future as well. “I love participating in outreach events and organizing professional events for my peers,” she says.

Bend, flow, build: the broad world of nanotech and 3D printing

https://projects.croucher.org.hk/news/bend-flow-build-the-broad-world-of-nanotech-and-3d-printing

 

MSE Post-Doc Attends UMich NextProf Workshop, Celebrates Diversity in Engineering

MSE Post-Doc Attends UMich NextProf Workshop, Celebrates Diversity in Engineering