Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Engineering (Page 1 of 12)

Cooking Up “Frustrated” Magnets in Search of Superconductivity

Sara Haravifard

A simplified version of Sara Haravifard’s recipe for new superconductors, by the National High Magnetic Field Laboratory

Duke physics professor Sara Haravifard is mixing, cooking, squishing and freezing “frustrated” magnetic crystals in search of the origins of superconductivity.

Superconductivity refers to the ability of electrons to travel endlessly through certain materials, called superconductors, without adding any energy — think of a car that can drive forever with no gas or electricity. And just the way gas-less, charge-less cars would make travel vastly cheaper, superconductivity has the potential to revolutionize electronics and energy industry.

But superconductors are extremely rare, and are usually only superconductive at extremely cold temperatures — too cold for any but a few highly specialized applications. A few “high-temperature” superconductors have been discovered, but scientists are still flummoxed at why and how these superconductors exist.

Haravifard hopes that her magnet experiments will reveal the origins of high-temperature superconductivity so that researchers can design and build new materials with this amazing property. In the process, her team may also discover materials that are useful in quantum computing, or even entirely new states of matter.

Learn more about their journey on this fascinating infographic by The National High Magnetic Field Laboratory.

Infographic describing magnetic crystal research

Infographic courtesy of the National High Magnetic Field Laboratory

Kara J. Manke, PhD

Post by Kara Manke

Trapping Light to Enhance Material Properties

Professor Mikkelsen is the Nortel Networks Assistant Professor of Electrical and Computer Engineering and Assistant Professor of Physics at Duke University.

A version of this article appeared in Pratt’s 2017 DukEngineer magazine.

Professor Maiken H. Mikkelsen uses optics to tailor the properties of materials, making them stronger and lighter than anything found in nature. This distinguished researcher also teaches my ECE 340: Optics and Photonics course, giving me a wonderful opportunity to ask about her research and experience at the Photonics Asia conference held in China in October 2016.

Below is an edited transcript of our interview.

Q: What sparked your interest in optics and photonics?
I was really excited about doing hands-on research where you could actually probe nanoscale and quantum phenomena from optical experiments. I started out looking into condensed matter and quantum information science and currently observe delicately designed nanostructures. Optics is, to some extent, a tool to modify the properties of materials.

Q: What does your lab do and how do students contribute?
During the last few years, my students and I have been structuring materials on the nanoscale to modify the local electromagnetic environment, which makes these materials behave in new ways. Students play a key role in all aspects of the research, from nanofabrication to performing optical experiments and presenting the results to the scientific community at conferences all over the world. The lab uses tiny metal structures to concentrate the incoming electromagnetic field of light to very small volumes — a research area known as plasmonics. Placing other materials in the near field of this modified environment causes the electrons to behave completely differently.

Platform based on metal nanostructures that allows the lab to dramatically enhance the radiative properties of emitters and other materials.

By controlling how these electrons behave and modifying the geometry of the material, we can gain a deeper understanding of the light-matter interactions. Combining these techniques with our optical experiments shows modifications to material properties that are much stronger than has been seen before. It’s been very exciting!

Q: And this research is what you presented at the Photonics Asia conference?
Yes. With this knowledge, we can enhance the properties of materials significantly, which in the future could lead to ultra-fast and much better LEDs, more efficient photodetectors, or more efficient solar cells and sensors. In Beijing, China, I gave an overview of this research at the leading meeting for the photonics and optics industries in Asia, as well as several other conferences and universities. It was very fulfilling to see how the research I do in a dark lab actually gets noticed around the world. It is always deeply inspiring to learn about recent research breakthroughs from other research groups.

Q: What is the main purpose of trying to find these improved materials?
I am motivated by furthering our fundamental understanding, such as how do light and matter interact when we get to really small scales and how this interaction can be leveraged to achieve useful properties. I believe you often achieve the biggest technological breakthroughs when you’re not trying to solve one particular problem, but creating new materials that could lay the groundwork for a wide range of new technologies. For example, semiconductor materials, with a set of properties that are found naturally, are the cornerstone of most modern technologies. But if you imagine that you now have an entirely new set of building blocks with tailored properties instead, we could revolutionize a lot of different technologies down the road.

The Mikkelsen Research Group. Back row, left to right: Qixin Shen, Andrew Traverso, Maiken Mikkelsen, Guoce Yang, Jon Stewart, Andrew Boyce. Front row, left to right: Wade Wilson, Daniela Cruz, Jiani Huang, Tamra Nebabu.

By improving or completely changing the fabrication technique of these light-matter interactions, new properties begin to emerge. Generally, there’s always a big desire to have something that’s lighter, smaller, more efficient and more flexible. One of the applications we’re targeting with this research is ultrafast LEDs. While future devices might not use this exact approach, the underlying physics will be crucial.

About a year ago, Facebook contacted me and was interested in utilizing our research for omnidirectional detectors that could be ultrafast and detect signals from a large range of incidence angles. This has led to a fruitful collaboration and is one example of how fundamental research can have applications in a wide range of areas — some that you may not even have imagined when you started!

 

Q: What would be your advice to young researchers still trying to decide a career path for themselves or those interested in optics and photonics?
What really helped me was starting to do undergraduate research. I listened to talks by different faculty, asked them to do undergraduate research, and worked on a volunteer basis in their labs. I think that’s really a great way to see if you’re interested in research — use the amazing opportunities both at Duke and around the country. Doing research requires a lot of patience, but I think no two days are the same; there’s always a lot of creativity involved while troubleshooting new problems. After all, if it was easy or if we knew how to do it, it would have already been done. But it hasn’t, so we have to figure it out — I think that is a lot of fun. Doing internships in optics and photonics companies is also another option to learn more about research and development in the industry. Get as many experiences as possible and give things a chance!

Professor Mikkelsen is best known for the first demonstration of nondestructive readout of a single electron spin, ultrafast manipulation of a single spin using all-optical techniques, and extreme radiative decay engineering using nanoantennas.

Mikkelsen has received numerous accolades, including the Cottrell Scholar Award, the Maria Goeppert Mayer Award, and a “triple crown” of Young Investigator Awards from the Air Force, Army and Navy. Her work has been published in the journals Science, Nature Photonics, and Nature Physics, to name a few. Professor Mikkelsen enjoys hiking, gardening, playing tennis, and traveling in her free time.

Learn more at mikkelsen.pratt.duke.edu.

Written by Anika Radiya-Dixit

Students Share Research Journeys at Bass Connections Showcase

From the highlands of north central Peru to high schools in North Carolina, student researchers in Duke’s Bass Connections program are gathering data in all sorts of unique places.

As the school year winds down, they packed into Duke’s Scharf Hall last week to hear one another’s stories.

Students and faculty gathered in Scharf Hall to learn about each other’s research at this year’s Bass Connections showcase. Photo by Jared Lazarus/Duke Photography.

The Bass Connections program brings together interdisciplinary teams of undergraduates, graduate students and professors to tackle big questions in research. This year’s showcase, which featured poster presentations and five “lightning talks,” was the first to include teams spanning all five of the program’s diverse themes: Brain and Society; Information, Society and Culture; Global Health; Education and Human Development; and Energy.

“The students wanted an opportunity to learn from one another about what they had been working on across all the different themes over the course of the year,” said Lori Bennear, associate professor of environmental economics and policy at the Nicholas School, during the opening remarks.

Students seized the chance, eagerly perusing peers’ posters and gathering for standing-room-only viewings of other team’s talks.

The different investigations took students from rural areas of Peru, where teams interviewed local residents to better understand the transmission of deadly diseases like malaria and leishmaniasis, to the North Carolina Museum of Art, where mathematicians and engineers worked side-by-side with artists to restore paintings.

Machine learning algorithms created by the Energy Data Analytics Lab can pick out buildings from a satellite image and estimate their energy consumption. Image courtesy Hoël Wiesner.

Students in the Energy Data Analytics Lab didn’t have to look much farther than their smart phones for the data they needed to better understand energy use.

“Here you can see a satellite image, very similar to one you can find on Google maps,” said Eric Peshkin, a junior mathematics major, as he showed an aerial photo of an urban area featuring buildings and a highway. “The question is how can this be useful to us as researchers?”

With the help of new machine-learning algorithms, images like these could soon give researchers oodles of valuable information about energy consumption, Peshkin said.

“For example, what if we could pick out buildings and estimate their energy usage on a per-building level?” said Hoël Wiesner, a second year master’s student at the Nicholas School. “There is not really a good data set for this out there because utilities that do have this information tend to keep it private for commercial reasons.”

The lab has had success developing algorithms that can estimate the size and location of solar panels from aerial photos. Peshkin and Wiesner described how they are now creating new algorithms that can first identify the size and locations of buildings in satellite imagery, and then estimate their energy usage. These tools could provide a quick and easy way to evaluate the total energy needs in any neighborhood, town or city in the U.S. or around the world.

“It’s not just that we can take one city, say Norfolk, Virginia, and estimate the buildings there. If you give us Reno, Tuscaloosa, Las Vegas, Pheonix — my hometown — you can absolutely get the per-building energy estimations,” Peshkin said. “And what that means is that policy makers will be more informed, NGOs will have the ability to best service their community, and more efficient, more accurate energy policy can be implemented.”

Some students’ research took them to the sidelines of local sports fields. Joost Op’t Eynde, a master’s student in biomedical engineering, described how he and his colleagues on a Brain and Society team are working with high school and youth football leagues to sort out what exactly happens to the brain during a high-impact sports game.

While a particularly nasty hit to the head might cause clear symptoms that can be diagnosed as a concussion, the accumulation of lesser impacts over the course of a game or season may also affect the brain. Eynde and his team are developing a set of tools to monitor both these impacts and their effects.

A standing-room only crowd listened to a team present on their work “Tackling Concussions.” Photo by Jared Lazarus/Duke Photography.

“We talk about inputs and outputs — what happens, and what are the results,” Eynde said. “For the inputs, we want to actually see when somebody gets hit, how they get hit, what kinds of things they experience, and what is going on in the head. And the output is we want to look at a way to assess objectively.”

The tools include surveys to estimate how often a player is impacted, an in-ear accelerometer called the DASHR that measures the intensity of jostles to the head, and tests of players’ performance on eye-tracking tasks.

“Right now we are looking on the scale of a season, maybe two seasons,” Eynde said. “What we would like to do in the future is actually follow some of these students throughout their career and get the full data for four years or however long they are involved in the program, and find out more of the long-term effects of what they experience.”

Kara J. Manke, PhD

Post by Kara Manke

Hidden No More: Women in STEM reflect on their Journeys

Back when she was a newly-minted Ph.D., Ayana Arce struggled to picture her future life as an experimental physicist. An African American woman in a field where the number of black women U.S. doctorates is still staggeringly small, Arce could not identify many role models who looked like her.

“I didn’t know what my life would look like as a black postdoc or faculty member,” Arce said.

But in the end, Arce – an associate professor of physics at Duke who went on to join the international team of physicists who discovered the Higgs Boson in 2012 — drew inspiration from her family.

“I looked to the women such as my mother who had had academic careers, and tried to think about how I could shape my life to look something like that, and I realized that it could be something I could make work,” Arce said.

Adrienne Stiff-Roberts, Fay Cobb Payton, Kyla McMullen, Robin Coger and Valerie Ashby on stage at the Hidden Figures No More panel discussion.

Adrienne Stiff-Roberts, Fay Cobb Payton, Kyla McMullen, Robin Coger and Valerie Ashby on stage at the Hidden Figures No More panel discussion. Credit: Chris Hildreth, Duke Photography.

Arce joined five other African American women faculty on the stage of Duke’s Griffith Film Theater March 23 for a warm and candid discussion on the joys and continuing challenges of their careers in science, technology, engineering and math (STEM) fields.

The panel, titled “Hidden Figures No More: Highlighting Phenomenal Women in STEM,” was inspired by Hidden Figures, a film which celebrates three pioneering African American women mathematicians who overcame racial segregation and prejudice to play pivotal roles in NASA’s first manned space flight.

The panel discussion was spearheaded by Johnna Frierson, Director of the Office of Diversity and Inclusion at the Pratt School of Engineering, and co-sponsored by the Duke Women’s Center. It was followed by a free screening of the film.

Though our society has made great strides since the days depicted in the film, women and minorities still remain under-represented in most STEM fields. Those who do pursue careers in STEM must overcome numerous hurdles, including unconscious bias and a lack of colleagues and role models who share their gender and race.

“In my field, at some of the smaller meetings, I am often the only black woman present at the conference, many times I’m the only black person at all,” said Adrienne Stiff-Roberts, an Associate Professor of Electrical and Computer Engineering at Duke. “In that atmosphere often it can be very challenging to engage with others in the way that you are supposed to, and you can feel like an outsider.”

Valerie Ashby and Ayana Arce onstage at the Hidden Figures No More panel discussion

Valerie Ashby and Ayana Arce shared their experiences. Credit: Chris Hildreth, Duke Photography

Stiff-Roberts and the other panelists have all excelled in the face of these challenges, making their marks in fields that include physics, chemistry, computer science, mechanical engineering and electrical engineering. On Thursday they shared their thoughts and experiences with a diverse audience of students, faculty, community members and more than a few kids.

Many of the panelists credited teams of mentors and sponsors for bolstering them when times got tough, and encouraged young scientists to form their own support squads.

Valerie Ashby, Dean at Duke’s Trinity College of Arts and Sciences, advised students to look for supporters who have a vision for what they can become, and are eager to help them get there. “Don’t assume that your help might come from people who you might expect your help to come from,” Ashby said.

The importance of cheerleading from friends, and particularly parents, can never be overestimated, the panelists said.

“Having someone who will celebrate every single positive with you is a beautiful thing,” said Ashby, in response to a mother seeking advice for how to support a daughter majoring in biomedical engineering. “If your daughter is like many of us, we’ll do 99 great things but if we do one wrong thing we will focus on the one wrong thing and think we can’t do anything.”

Women in STEM can also be important and powerful allies to each other, noted Kyla McMullen, an Assistant Professor of Computer and Information Science at the University of Florida.

“I have seen situations where a woman suggests something and then the male next her says the same thing and gets the credit,” McMullen said. “That still happens, but one thing that I see help is when women make an effort to reiterate the points made by other women so people can see who credit should be attributed to.”

With all the advice out there for young people who are striving to succeed in STEM – particularly women and underrepresented minorities – the panelists advocated that everyone to stay true to themselves, above all.

“I want to encourage everyone in the room – whether you are a budding scientist or woman scholar – you can be yourself,” Ashby said. “You should make up in your mind that you are going to be yourself, no matter what.”

Kara J. Manke, PhD

Post by Kara Manke

Creating Technology That Understands Human Emotions

“If you – as a human – want to know how somebody feels, for what might you look?” Professor Shaundra Daily asked the audience during an ECE seminar last week.

“Facial expressions.”
“Body Language.”
“Tone of voice.”
“They could tell you!”

Over 50 students and faculty gathered over cookies and fruits for Dr. Daily’s talk on designing applications to support personal growth. Dr. Daily is an Associate Professor in the Department of Computer and Information Science and Engineering at the University of Florida interested in affective computing and STEM education.

Dr. Daily explaining the various types of devices used to analyze people’s feelings and emotions. For example, pressure sensors on a computer mouse helped measure the frustration of participants as they filled out an online form.

Affective Computing

The visual and auditory cues proposed above give a human clues about the emotions of another human. Can we use technology to better understand our mental state? Is it possible to develop software applications that can play a role in supporting emotional self-awareness and empathy development?

Until recently, technologists have largely ignored emotion in understanding human learning and communication processes, partly because it has been misunderstood and hard to measure. Asking the questions above, affective computing researchers use pattern analysis, signal processing, and machine learning to extract affective information from signals that human beings express. This is integral to restore a proper balance between emotion and cognition in designing technologies to address human needs.

Dr. Daily and her group of researchers used skin conductance as a measure of engagement and memory stimulation. Changes in skin conductance, or the measure of sweat secretion from sweat gland, are triggered by arousal. For example, a nervous person produces more sweat than a sleeping or calm individual, resulting in an increase in skin conductance.

Galvactivators, devices that sense and communicate skin conductivity, are often placed on the palms, which have a high density of the eccrine sweat glands.

Applying this knowledge to the field of education, can we give a teacher physiologically-based information on student engagement during class lectures? Dr. Daily initiated Project EngageMe by placing galvactivators like the one in the picture above on the palms of students in a college classroom. Professors were able to use the results chart to reflect on different parts and types of lectures based on the responses from the class as a whole, as well as analyze specific students to better understand the effects of their teaching methods.

Project EngageMe: Screenshot of digital prototype of the reading from the galvactivator of an individual student.

The project ended up causing quite a bit of controversy, however, due to privacy issues as well our understanding of skin conductance. Skin conductance can increase due to a variety of reasons – a student watching a funny video on Facebook might display similar levels of conductance as an attentive student. Thus, the results on the graph are not necessarily correlated with events in the classroom.

Educational Research

Daily’s research blends computational learning with social and emotional learning. Her projects encourage students to develop computational thinking through reflecting on the community with digital storytelling in MIT’s Scratch, learning to use 3D printers and laser cutters, and expressing ideas using robotics and sensors attached to their body.

VENVI, Dr. Daily’s latest research, uses dance to teach basic computational concepts. By allowing users to program a 3D virtual character that follows dance movements, VENVI reinforces important programming concepts such as step sequences, ‘for’ and ‘while’ loops of repeated moves, and functions with conditions for which the character can do the steps created!

 

 

Dr. Daily and her research group observed increased interest from students in pursuing STEM fields as well as a shift in their opinion of computer science. Drawings from Dr. Daily’s Women in STEM camp completed on the first day consisted of computer scientist representations as primarily frazzled males coding in a small office, while those drawn after learning with VENVI included more females and engagement in collaborative activities.

VENVI is a programming software that allows users to program a virtual character to perform a sequence of steps in a 3D virtual environment!

In human-to-human interactions, we are able draw on our experiences to connect and empathize with each other. As robots and virtual machines grow to take increasing roles in our daily lives, it’s time to start designing emotionally intelligent devices that can learn to empathize with us as well.

Post by Anika Radiya-Dixit

Science Meets Policy, and Maybe They Even Understand Each Other!

As we’ve seen many times, when complex scientific problems like stem cells, alternative energy or mental illness meet the policy world, things can get a little messy. Scientists generally don’t know much about law and policy, and very few policymakers are conversant with the specialized dialects of the sciences.

A screenshot of SciPol’s handy news page.

Add the recent rapid emergence of autonomous vehicles, artificial intelligence and gene editing, and you can see things aren’t going to get any easier!

To try to help, Duke’s Science and Society initiative has launched an ambitious policy analysis group called SciPol that hopes to offer great insights into the intersection of scientific knowledge and policymaking. Their goal is to be a key source of non-biased, high-quality information for policymakers, academics, commercial interests, nonprofits and journalists.

“We’re really hoping to bridge the gap and make science and policy accessible,” said Andrew Pericak, a contributor and editor of the service who has a 2016 masters in environmental management from the Nicholas School.

The program also will serve as a practical training ground for students who aspire to live and work in that rarefied space between two realms, and will provide them with published work to help them land internships and jobs, said SciPol director Aubrey Incorvaia, a 2009 masters graduate of the Sanford School of Public Policy.

Aubrey Incorvaia chatted with law professor Jeff Ward (center) and Science and Society fellow Thomas Williams at the kickoff event.

SciPol launched quietly in the fall with a collection of policy development briefs focused on neuroscience, genetics and genomics. Robotics and artificial intelligence coverage began at the start of January. Nanotechnology will launch later this semester and preparations are being made for energy to come online later in the year. Nearly all topics are led by a PhD in that field.

“This might be a different type of writing than you’re used to!” Pericak told a meeting of prospective undergraduate and graduate student authors at an orientation session last week.

Some courses will be making SciPol brief writing a part of their requirements, including law professor Jeff Ward’s section on the frontier of robotics law and ethics. “We’re doing a big technology push in the law school, and this is a part of it,” Ward said.

Because the research and writing is a learning exercise, briefs are published only after a rigorous process of review and editing.

A quick glance at the latest offerings shows in-depth policy analyses of aerial drones, automated vehicles, genetically modified salmon, sports concussions and dietary supplements that claim to boost brain power.

To keep up with the latest developments, the SciPol staff maintains searches on WestLaw, the Federal Register and other sources to see where science policy is happening. “But we are probably missing some things, just because the government does so much,” Pericak said.

Post by Karl Leif Bates

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