Duke Research Blog

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

Category: Physics (Page 2 of 14)

Young Scientists, Making the Rounds

“Can you make a photosynthetic human?!” an 8th grader enthusiastically asks me while staring at a tiny fern in a jar.

He’s not the only one who asked me that either — another student asked if Superman was a plant, since he gets his power from the sun.

These aren’t the normal questions I get about my research as a Biology PhD candidate studying how plants get nutrients, but they were perfect for the day’s activity –A science round robin with Durham eighth-graders.

Biology grad student Leslie Slota showing Durham 8th graders some fun science.

After seeing a post under #scicomm on Twitter describing a public engagement activity for scientists, I put together a group of Duke graduate scientists to visit local middle schools and share our science with kids. We had students from biomedical engineering, physics, developmental biology, statistics, and many others — a pretty diverse range of sciences.

With help from David Stein at the Duke-Durham Neighborhood Partnership, we made connections with science teachers at the Durham School of the Arts and Lakewood Montessori school, and the event was in motion!

The outreach activity we developed works like speed dating, where people pair up, talk for 3-5 mins, and then rotate. We started out calling it “Science Speed Dating,” but for a middle school audience, we thought “Science Round-Robin” was more appropriate. Typically, a round-robin is a tournament where every team plays each of the other teams. So, every middle schooler got to meet each of us graduate students and talk to us about what we do.

The topics ranged from growing back limbs and mapping the brain, to using math to choose medicines and manipulating the different states of matter.

The kids were really excited for our visit, and kept asking their teachers for the inside scoop on what we did.

After much anticipation, and a little training and practice with Jory Weintraub from the Science & Society Initiative, two groups of 7-12 graduate students armed themselves with photos, animals, plants, and activities related to our work and went to visit these science classes full of eager students.

First-year MGM grad student Tulika Singh (top right) brought cardboard props to show students how antibodies match up with cell receptors.

“The kids really enjoyed it!” said Alex LeMay, middle- and high-school science teacher at the Durham School of the Arts. “They also mentioned that the grad students were really good at explaining ideas in a simple way, while still not talking down to them.”

That’s the ultimate trick with science communication: simplifying what we do, but not talking to people like they’re stupid.

I’m sure you’ve heard the old saying, “dumb it down.” But it really doesn’t work that way. These kids were bright, and often we found them asking questions we’re actively researching in our work. We don’t need to talk down to them, we just need to talk to them without all of the exclusive trappings of science. That was one thing the grad students picked up on too.

“It’s really useful to take a step back from the minutia of our projects and look at the big picture,” said Shannon McNulty, a PhD candidate in Molecular Genetics and Microbiology.

The kids also loved the enthusiasm we showed for our work! That made a big difference in whether they were interested in learning more and asking questions. Take note, fellow scientists: share your enthusiasm for what you do, it’s contagious!

Another thing that worked really well was connecting with the students in a personal way. According to Ms. LeMay, “if the person seemed to like them, they wanted to learn more.” Several of the grad students would ask each student their names and what they were passionate about, or even talk about their own passions outside of their research, and these simple questions allowed the students to connect as people.

There was one girl who shared with me that she didn’t know what she wanted to do when she grew up, and I told her that’s exactly where I was when I was in 8th grade too. We then bonded over our mutual love of baking, and through that interaction she saw herself reflected in me a little bit; making a career in science seem like a possibility, which is especially important for a young girl with a growing interest in science.

Making the rounds in these science classrooms, we learned just as much from the students we spoke to as they did from us. Our lesson being: science outreach is a really rewarding way to spend our time, and who knows, maybe we’ll even spark someone who loves Superman to figure out how to make the first photosynthesizing super-person!

Guest post by Ariana Eily , PhD Candidate in Biology, shown sharing her floating ferns at left.

 

Acoustic Metamaterials: Designing Plastic to Bend Sound

I recently toured Dr. Steven Cummer’s lab in Duke Engineering to learn about metamaterials, synthetic materials used to manipulate sound and light waves.

Acoustic metamaterials recently bent an incoming sound into the shape of an A, which the researchers called an acoustic hologram.

Acoustic metamaterials recently bent an incoming sound into the shape of an A, which the researchers called an acoustic hologram.

Cummer’s graduate student Abel Xie first showed me the Sound Propagator. It was made of small pieces that looked similar to legos stacked in a wall. These acoustic metamaterials were made of plastic and contained many winding pathways that delay and propagate, or change the direction, of sound waves. The pieces were configured in certain ways so they could design a sound field, a sort of acoustic hologram.

These metamaterials can be configured to direct a 4 kHz sound wave into the shape of a letter ‘A’. The researchers measured the outgoing sound wave using a 2D sweeping microphone that passed back and forth over the A-shaped sound like a lawnmower, moving to the right, then up, then left, etc. The arrangement of metamaterials that reconfigures sound waves is called a lens, because it can focus sound waves to one or more points like a light-bending lens.

Xie then showed me a version of the acoustic metamaterials 10 times smaller that propagated ultrasonic (40 KHz) sound waves. He told me that since 40 kHz was well out of the human range of hearing, it could be a viable option for the wireless non-contact charging of devices like phones. The smaller wave propagator could direct inaudible sound waves to your device, and then another piece of technology called a transfuser would convert acoustic energy into electrical energy.

This structure, with a microphone in the middle, can perform the "cocktail party" trick that humans can -- figuring out where in the room a sound is coming from.

This structure with a microphone in the middle can perform the “cocktail party” trick that humans can — picking out once voice among many.

Now that the waves have been directed, how do we read them? Xie directed me to what looked like a plastic cheesecake in the middle of the table. It was deep and beige and was split into many ‘slices.’ Each slice was further divided into a unique honeycomb of varying depth. The slices were separated from each by glass panes. This directed the soundwaves across the unique honeycomb of each slice towards the lone microphone in the middle. A microphone would be able to recognize where the sound was coming from based on how the wave had changed while it passed over the different honeycomb pattern of each slice.

Xie described the microphone’s ability to distinguish where a sound is coming from and comprehend that specific sound as the “cocktail party effect,” or the human ability to pick out one person speaking in a noisy room. This dense plastic sound sensor is able to distinguish up to three different people speaking and determine where they are in relation to the microphone. He explained how this technology could be miniaturized and implemented in devices like the Amazon Echo to make them more efficient.

Dr. Cummer and Abel Xie’s research is changing the way we think about microphones and sound, and may one day improve all kinds of technology ranging from digital assistants to wirelessly charging your phone.

Frank diLustro

Frank diLustro is a senior at the North Carolina School for Science and Math.

 

3D-Printable Material Sets Terminator’s Eyes Aglow

Pumpkins just not cutting it for you this year?

If you want a unique, hand-made Halloween decoration – and happen to have access to a 3D printer – Duke graduate student Patrick Flowers has just the project for you: this 3D-printed Terminator head, complete with shining, blood-red eyes.

[youtube https://www.youtube.com/watch?v=llDaqaicGGk]

Flowers, a PhD candidate in Benjamin Wiley’s lab, is not spending his time studying early eighties action flicks or the Governator’s best break-out roles. Instead, he and his labmates are working hard to brew up highly-conductive, copper-based materials that can be 3D printed into multilayer circuits – just like the one powering this Terminator’s glowing LED eyes.

Their latest copper concoction, which they have named “Electrifi,” is about 100 times more conductive than other materials on the market. The team has a taken out a provisional patent on Electrifi and also started a company, named Multi3D, where 3D-printing aficionados can purchase the material to include in their very own devices.

Micro CT scan of the 3D Terminator head

This X-ray view of Terminator’s head, collected with Duke SMIF’s Micro CT scanner, shows the embedded 3D circuit powering his LED eyes.

Creating a conductive, 3D-printable material is a lot trickier than just throwing some copper into a printer and going to town, Flowers said.

“Copper is really conductive originally, but if you try to extrude it out of a hot nozzle like you have to do in order to do this 3D printing, then it quickly loses all its properties,” Flowers said. And conductive materials that can stand the heat, like silver, are too expensive to use on any sort of scale, he added.

To bring the benefits of 3D printing to the world of electric circuits, Flowers and his labmates are experimenting with mixing copper with other materials to help it stay conductive through this extrusion process.

“This lab has a long history of working with copper – copper nanowires, copper particles, copper nanoparticles – so we’ve got a lot of little tricks that we use to maintain the conductivity,” Flowers said.

The team is currently testing the limits of their new material and plans to publish their findings soon. In the meantime, Flowers is busy exploring the other capabilities of Electrifi — outside of plastic android noggins.

“The circuit inside this guy is really simple, but it does show the capabilities of the material: it is embedded, it shows that I can go down, over, up, out, and go to a couple of eyes,” Flowers said. “Now I want to expand on that and show that you can make these really complicated embedded structures that have multiple layers and multiple components, other than just LEDs.”

adding_battery

Kara J. Manke, PhD

Post by Kara Manke

Girls Get An Eye-Opening Introduction to Photonics

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Demonstration of the Relationship between Solar Power and Hydrogen Fuel. Image courtesy of DukeEngineering.

Last week I attended the “Exploring Light Technologies” open house hosted by the Fitzpatrick Institute for Photonics, held to honor International “Introduce a Girl to Photonics” Week. It was amazing!

I was particularly enraptured by a MEDx Wireless Technology presentation and demonstration titled “Using Light to Monitor Health and View Health Information.” There were three “stations” with a presenter at each station.

At the first station, the presenter, Julie, discussed how wearable technologies are used in optical heart rate monitoring. For example, a finger pulse oximeter uses light to measure blood oxygen levels and heart rates, and fitness trackers typically contain LED lights in the band. These lights shine into the skin and the devices use algorithms to read the amount of light scattered by the flow of blood, thus measuring heart rate.

At the second station, the presenter, Jackie, spoke about head-mounted displays and their uses. The Google Glass helped inspire the creation of the Microsoft Hololens, a new holographic piece of technology resembling a hybrid of laboratory goggles and a helmet. According to Jackie, the Microsoft Hololens “uses light to generate 3D objects we can see in our environment.”

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Using the Microsoft Hololens. Image courtesy of DukeEngineering.

After viewing a video on how the holographic technology worked, I put on the Microsoft Hololens at the demonstration station. The team had set up 3D images of a cat, a dog and a chimpanzee. “Focus the white point of light on the object and make an L-shape with your fingers,” directed Eric, the overseer. “Snap to make the objects move.” With the heavy Hololens pressing down on my nose, I did as he directed. Moving my head moved the point of light. Using either hand to snap made the dog bark, the cat meow and lick its paws, and the chimpanzee eat. Even more interesting was the fact that I could move around the animals and see every angle, even when the objects were in motion. Throughout the day, I saw visitors of all ages with big smiles on their faces, patting and “snapping” at the air.

Applications of the Microsoft Hololens are promising. In the medical field, they can be used to display patient health information or electronic health records in one’s line of sight. In health education, students can view displays of interactive 3D anatomical animations. Architects can use the Hololens to explore buildings. “Imagine learning about Rome in the classroom. Suddenly, you can actually be in Rome, see the architecture, and explore the streets,” Jackie said. “[The Microsoft Hololens] deepens the educational experience.”

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Tour of the Facilities. Image courtesy of DukeEngineering.

Throughout the day, I oo-ed and aw-ed at the three floors-worth of research presentations lining the walls. Interesting questions were posed on easy-to-comprehend posters, even for a non-engineer such as myself. The event organizers truly did make sure that all visitors would find at least one presentation to pique their interest. There were photonic displays and demonstrations with topics ranging from art to medicine to photography to energy conservation…you get my point.

Truly an eye-opening experience!

Post by Meg Shiehmeg_shieh_100hed

LHC Reveals No New Physics Yet, but Duke Scientists Stay the Hunt

For particle physicists, “expect the unexpected” is more than just a catchy tagline.

Duke scientists on the Large Hadron Collider’s (LHC’s) ATLAS collaboration are on the hunt for hints of the unexpected: new, undiscovered particles or forces that could point to theories beyond the remarkably accurate, yet clearly incomplete, Standard Model of physics.

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The Duke physics team at CERN this summer, gathered in front of a model of one of the LHC’s superconducting electromagnets. (Left to right: Ifeanyi Achu, Emily Stump, Elisa Zhang, Hannah Glaser, Wei Tang, Spencer Griswold, Andrea Bocci, Minyu Feng, Shu Li and Al Goshaw).

But the tsunami of new data coming out of the LHC’s current run, which began May of this year, has yet to provide any promising clues. Notably, at the ICHEP conference in Chicago, ATLAS collaboration members presented new results showing that an intriguing “bump” observed in 2015 data — speculated to be the first evidence of a completely new particle six times the mass of the Higgs — was likely just a statistical fluctuation in the data.

“It was quite amazing,” said Duke physics professor Al Goshaw, a member of the ATLAS collaboration. “With this new data there should have been a very clear signal, and there is nothing. It’s just absolutely gone.”

Goshaw has spent much of the summer at CERN, leading a team of undergraduate and graduate scientists crunching the numbers on the new data. Undeterred by the results presented in Chicago, he says the Duke team is still hard at work searching for other massive new particles.

“Our plan is to take the full data set collected in 2016 and extend the search for a new force-carrying particle up to much higher energies,” Goshaw said. “The search will go up to about 25 times the mass of the top quark or 35 times the mass of the Higgs.” They aim to have the results of this analysis ready by early 2017.

Why all the interest in tracking down these massive new particles?

ATLAS-CONF

Particle and energy spray recorded following a high-energy proton-proton collision event at the LHC in May. (Credit: CERN)

Goshaw says there are a myriad of alternative theories to the standard model, so many that trying to test specific predictions of individual models would be prohibitively time-consuming.

“But there is one prediction which they almost all make, and that is that there should be additional massive particles beyond those contained in the standard model,” Goshaw said. “So a generic way to search is to look for the new forces which are indicated by a force carrier, a massive new particle.”

The new data, collected at higher energies than the 2010-2012 run and with higher “brightness” or luminosity than the 2015 run, gives physicists the best chance yet of spotting an elusive new particle.

However, it’s not always looking at a plot and looking for a little bump, Goshaw says. Physicists, including the Duke team, are also utilizing the new data to perform highly precise tests of the standard model.

“The precision tests are really trying to find cracks in the standard model,” Goshaw said. “There could be particles that are so massive that we cannot detect them, but they may appear as subtle deviations in standard model predictions.”

But for now, the tried-and-true still holds. “It is quite extraordinary that, with these beautiful tests, everything is still described by the standard model,” Goshaw said.

Kara J. Manke, PhD

Post by Kara Manke

Fledgling Physicists Embark for the LHC

For physics student Hannah Glaser, taking off for a summer of hands-on research at the world’s largest particle collider is both exciting and terrifying.

But, Glaser says, joining the thousands of scientist at work at the Large Hadron Collider (LHC) also feels a lot like going home.

“It’s such a huge relief to finally be in a group of people who who are interested in the same exact kind of problems that you are,” said Glaser, a rising junior at Virginia Tech. “It really is just this ridiculous nerdy feeling when you finally meet a group of people who have the same obsession with math and science.”

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Undergraduate physicists embarking for a summer at the LHC, posed in front of a map of CERN and neighboring town St. Genis hand-drawn by physics professor Al Goshaw. From left: Wei Tang (Duke), Ifeanyi Achu (Southern Methodist University), Spencer Griswold (Clarkson University), Elisa Zhang (Duke), Emily Stump (Williams College) and Hannah Glaser (Virginia Tech).

Glaser is among six undergraduates — two from Duke and four from other institutions — who will be working alongside Duke scientists at the LHC’s ATLAS experiment this summer. Each will tackle a bite-sized piece of the immense particle physics project, primarily by helping to analyze the massive amounts of data generated by the collider.

“Just going to CERN will be a mind-blowing experience,” said Ifeanyi Achu, a junior at Southern Methodist University, at an orientation event at Duke last week. “I’m looking forward to getting a window into what life could be like as a physics researcher.”

Before setting off for CERN, the group spent the month of June with other REU students on Duke’s campus, learning the basics of quantum mechanics and Root, a software platform used CERN and other particle accelerators around the world.

In addition to grappling with complex physics, the students also had to prepare for the more practical aspects of spending six weeks abroad – like the fact that they will be living in the French town of St. Genis while working in Switzerland, requiring that they regularly cross the border and navigate among two or more currencies and languages.

However, the thrill of spending time with some of the world’s biggest experiments should make the travel anxiety worth it.

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Duke student Wei Tang hopes to get a picture with a giant LHC detector while working at CERN this summer. (Credit: CERN)

“I’m definitely looking forward to taking a picture with a giant detector,” said Wei Tang, a Duke junior majoring in physics and computer science.

As members of the ATLAS experiment, The Duke high-energy physics team hopes to spot particles or forces not predicted by the Standard Model of physics, the theoretical framework that currently forms the basis of our physical understanding of the universe. New particles or forces could provide clues to solving some of the mysteries that remain in physics, such as what is the nature of dark matter.

“This is probably the most exciting year for the LHC,” said Duke physicist Al Goshaw, who will be onsite advising the students for part of the summer. “Data taken in this run really offers an extraordinary opportunity to look for physics beyond the standard model because it is the first time the LHC is operating at its full potential. It really could be the discovery run, and we are excited to be involved in that.”

But even if new discoveries aren’t made this summer, the students are still thrilled to be a part of the experiment.

“To know that you have done just a tiny bit of science at CERN – it’s just a dream come true for anyone interested in particle physics,” Glaser said.

Kara J. Manke, PhD

Post by Kara Manke

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