Aurelia Butler

A team of researchers led by Director Rod Ruoff at the Center for Multidimensional Carbon Materials (CMCM) within the Institute for Basic Science (IBS), including graduate students at the Ulsan National Institute of Science and Technology (UNIST), have achieved growth and characterization of large area, single-crystal graphene that has no wrinkles, folds, or adlayers. It can be said to be the most perfect graphene that has been grown and characterized, to date.
Director Ruoff notes, “This pioneering breakthrough was due to many contributing factors, including human ingenuity and the ability of the CMCM researchers to reproducibly make large-area single-crystal Cu-Ni(111) foils, on which the graphene was grown by chemical vapor deposition (CVD) using a mixture of ethylene with hydrogen in a stream of argon gas.” Student Meihui Wang, Dr. Ming Huang, and Dr. Da Luo along with Ruoff undertook a series of experiments of growing single-crystal and single-layer graphene on such ‘home-made’ Cu-Ni(111) foils under different temperatures.
The team had previously reported single-crystal and adlayer-free films of graphene which were grown using methane at temperatures of ~1320 Kelvin (K) degrees on Cu(111) foils. Adlayers refer to small “islands” of regions that have another layer of graphene present. However, these films always contained long “folds” that are the consequence of tall wrinkles that form as the graphene is cooled from the growth temperature down to room temperature. This results in an undesirable reduction in the performance of graphene field effect transistor (GFET) if the “fold” is in the active region of the GFET. The folds also contain “cracks” that lower the mechanical strength of the graphene.
The next exciting challenge was thus eliminating these folds.
CMCM researchers first implemented a series of ‘cycling’ experiments that involved “cycling” the temperature immediately after growing the graphene at 1320 K. These experiments showed that the folds are formed at or above 1020 K during the cooling process. After learning this, the team decided to grow graphene on Cu-Ni(111) foils at several different temperatures around 1020 K, which led to a discovery that large-area, high-quality, fold-free, and adlayer-free single-crystal graphene films can be grown in a temperature range between 1000 K and 1030 K. “This fold-free graphene film forms as a single crystal over the entire growth substrate because it shows a single orientation over a large-area low-energy electron diffraction (LEED) patterns,” noted SEONG Won Kyung, a senior research fellow in CMCM who installed the LEED equipment in the center. GFETs were then patterned on this single-crystal fold-free graphene in a variety of directions by UNIST graduate student Yunqing Li. These GFETs showed remarkably uniform performance with average room temperature electron and hole mobilities of 7.0 ± 1.0 × 103 cm2 V-1 s-1. Li notes, “Such remarkably uniform performance is possible because the fold-free graphene film is a single crystal with essentially no imperfections.”
Importantly, the research team was able to achieve “scaling up” of graphene production using this method. The graphene was successfully grown on 5 foils (dimension 4 cm x 7 cm) simultaneously in a 6-inch diameter home-built quartz furnace. “Our method of growing fold-free graphene films is very reproducible, with each foil yielding two identical pieces of high-quality graphene films on both sides of the foil,” and “By using the electrochemical bubbling transfer method, graphene can be delaminated in about 1 minute and the Cu-Ni(111) foil can be quickly readied for the next growth/transfer cycle,” notes Meihui Wang. Ming Huang adds, “When we tested the weight loss of Cu-Ni(111) foils after 5 runs of growth and transfers, the net loss was only 0.0001 grams. This means that our growth and transfer methods using the Cu-Ni(111) can be performed repeatedly, essentially indefinitely.”
In the process of achieving fold-free single-crystal graphene, the researchers also discovered the reasons behind the formation of these folds. High-resolution TEM imaging was performed by student CHOE Myeonggi and Prof. LEE Zonghoon (a group leader in CMCM and professor at UNIST) to observe the cross-sections of the samples grown above 1040 K. They discovered that the deadhesion, which is the cause of the folds, is initiated at the “bunched step edge” regions between the single crystal Cu-Ni(111) plateaus. “This deadhesion at the bunched step edge regions triggers the formation of graphene folds perpendicular to the step edge direction,” noted co-corresponding author Luo. Ruoff further notes that “We discovered that step-bunching of a Cu-Ni(111) foil surface suddenly occurs at about 1030 K, and this ‘surface reconstruction’ is the reason why the critical growth temperature of fold-free graphene is at ~1030 K or below.”
Such large-area fold-free single-crystal graphene film allows for the straightforward fabrication of integrated high-performance devices oriented in any direction over the entire graphene film. These single-crystal graphene films will be important for further advances in basic science, which will lead to new applications in electronic, photonic, mechanical, thermal, and other areas. The near-perfect graphene is also useful for stacking, either with itself and/or with other 2D materials, to further expand the range of likely applications. Given that the Cu-Ni(111) foils can be used repeatedly and that the graphene can be transferred to other substrates in less than one minute, the scalable manufacturing using this process is also highly promising.
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Genetically encoded reporter proteins have been a mainstay of biotechnology research, allowing scientists to track gene expression, understand intracellular processes and debug engineered genetic circuits.
But conventional reporting schemes that rely on fluorescence and other optical approaches come with practical limitations that could cast a shadow over the field’s future progress. Now, researchers at the University of Washington and Microsoft have created a “nanopore-tal” into what is happening inside these complex biological systems, allowing scientists to see reporter proteins in a whole new light.
The team introduced a new class of reporter proteins that can be directly read by a commercially available nanopore sensing device. The new system ? dubbed “Nanopore-addressable protein Tags Engineered as Reporters” or “NanoporeTERs” ? can detect multiple protein expression levels from bacterial and human cell cultures far beyond the capacity of existing techniques.
The study was published Aug. 12 in Nature Biotechnology.
“NanoporeTERs offer a new and richer lexicon for engineered cells to express themselves and shed new light on the factors they are designed to track. They can tell us a lot more about what is happening in their environment all at once,” said co-lead author Nicolas Cardozo, a doctoral student with the UW Molecular Engineering and Sciences Institute. “We’re essentially making it possible for these cells to ‘talk’ to computers about what’s happening in their surroundings at a new level of detail, scale and efficiency that will enable deeper analysis than what we could do before.”
For conventional labeling methods, researchers can track only a few optical reporter proteins, such as green fluorescent protein, simultaneously because of their overlapping spectral properties. For example, it’s difficult to distinguish between more than three different colors of fluorescent proteins at once. In contrast, NanoporeTERs were designed to carry distinct protein “barcodes” composed of strings of amino acids that, when used in combination, allow at least ten times more multiplexing possibilities. More

The old adage “never let them see you sweat,” doesn’t apply in the electrical and computer engineering lab of Rose Faghih, assistant professor of electrical and computer engineering in the University of Houston Cullen College of Engineering. In fact, Faghih seeks sweat, the kind that beads on your upper lip when you’re nervous — skin conductance response (SCR) as the change in sweat activity is scientifically called. It is through that measure that Faghih is reporting the ability to monitor stress and even help lower it.
To collect and study these physiological signals of stress, Faghih’s research team has built a new closed-loop technology by placing two electrodes on smartwatch-type wearables. Once the signal for stress is detected, a reminder is sent through the smartwatch, for example, to listen to relaxing music to calm down. Thus, the loop is closed as the detected stress launches the subtle suggestion.
“This study is one of the very first steps toward the ultimate goal of monitoring brain responses using wearable devices and closing the loop to keep a person’s stress state within a pleasant range,” reports Faghih in the journal IEEE Xplore.
Electrodermal activity (i.e., the electrical conductivity of the skin) carries important information about the brain’s cognitive stress. Faghih uses signal processing techniques to track the hidden stress state and design an appropriate control algorithm for regulating the stress state and closing the loop. The results of the research illustrate the efficiency of the proposed approach and validate its feasibility of being implemented in real life.
“To the best of our knowledge, this research is one of the very first to relate the cognitive stress state to the changes in SCR events and design the control mechanism to close the loop in a real-time simulation system,” said UH doctoral student and lead study author Fekri Azgomi, who accomplished the task of closed-loop cognitive stress regulation in a simulation study based on experimental data.
Due to the increased ubiquity of wearable devices capable of measuring cognitive stress-related variables, the proposed architecture is an initial step toward treating cognitive disorders using non-invasive brain state decoding.
“The final results verify that the proposed architecture has great potential to be implemented in a wrist-worn wearable device and used in daily life,” said Faghih.
Stress is a worldwide issue that can result in catastrophic health and financial complications. A recent Gallup poll found that more than one in three adults (35%) worldwide said they experienced stress during “a lot of the day yesterday.”
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Materials provided by University of Houston. Original written by Laurie Fickman. Note: Content may be edited for style and length. More

Scientists have taken the clearest picture yet of electronic particles that make up a mysterious magnetic state called quantum spin liquid (QSL).
The achievement could facilitate the development of superfast quantum computers and energy-efficient superconductors.
The scientists are the first to capture an image of how electrons in a QSL decompose into spin-like particles called spinons and charge-like particles called chargons.
“Other studies have seen various footprints of this phenomenon, but we have an actual picture of the state in which the spinon lives. This is something new,” said study leader Mike Crommie, a senior faculty scientist at Lawrence Berkeley National Laboratory (Berkeley Lab) and physics professor at UC.
“Spinons are like ghost particles. They are like the Big Foot of quantum physics — people say that they’ve seen them, but it’s hard to prove that they exist,” said co-author Sung-Kwan Mo, a staff scientist at Berkeley Lab’s Advanced Light Source. “With our method we’ve provided some of the best evidence to date.”
A surprise catch from a quantum wave
In a QSL, spinons freely move about carrying heat and spin — but no electrical charge. To detect them, most researchers have relied on techniques that look for their heat signatures. More

To train robots how to work independently but cooperatively, researchers at the University of Cincinnati gave them a relatable task: move a couch.
If you’ve ever helped someone move furniture, you know it takes coordination — simultaneously pushing or pulling and reacting based on what your helper is doing. That makes it an ideal problem to examine collaboration between robots, said Andrew Barth, a doctoral student in UC’s College of Engineering and Applied Science.
“It’s a good metaphor for cooperation,” Barth said.
In the Intelligent Robotics and Autonomous Systems Lab of UC aerospace engineering professor Ou Ma, student researchers developed artificial intelligence to train robots to work together to move a couch — or in this case a long rod that served as a stand-in — around two obstacles and through a narrow door in computer simulations.
“We made it a little more difficult on ourselves. We want to accomplish the task with as little communication as possible among the robots,” student Barth said.
He was lead author of a study on the project published in the journal Intelligent Service Robotics. Professor Ma, UC doctoral student Yufeng Sun and UC senior research associate Lin Zhang were co-authors. More

New research published in the journal Clinical Psychological Science reveals that teenagers (ages 13-17) in low socioeconomic settings who spend a moderate amount of time online after a stressful experience deal with adversity far better than those who spend many hours online or avoid digital technology altogether.
“Adolescents are smart, and they make use of technology to their own advantage. Because adolescents in disadvantaged settings tend to have fewer local supports, the study sought to find out whether online engagement helped reduce their stress,” said lead author Kathryn Modecki with Griffith University’s Menzies Health Institute and School of Applied Psychology. “There has been a tendency to assume that technology use by teens is negative and harmful, but such a broad assumption isn’t borne out by what we know about the developmental stage of adolescence.”
To gather firsthand data on teens and technology, the researchers provided iPhones to more than 200 adolescents living in low socioeconomic settings. The teens were instructed to report on their technology use, stressors, and emotions five times a day for a week while using the iPhones exactly as they would use personal smartphones. The data were used to compare the emotional states of adolescents who used technology moderately, excessively, or not at all when coping with stress.
The results revealed that adolescents who engaged with technology in moderation in the hours after a stressful situation bounced back more readily and experienced smaller surges in negative emotions, like sadness and worry, compared to adolescents who didn’t use technology or who routinely used technology as a coping mechanism.
“We found a just-right ‘Goldilocks’ effect in which moderate amounts of online coping helped mitigate surges in negative emotions and dips in happiness,” said Modecki. “In the face of daily stressors, when adolescents engaged in emotional support seeking, they experienced better short-term stress relief.”
According to the researchers, the online space serves not just as a short-term distraction but as a resource for adolescents to find support and information about what is troubling them. By leveling the playing field for accessing that information and support, this coping strategy may be especially pertinent for teens in low-income settings.
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Researchers from the Graduate School of Engineering, Osaka City University have succeeded in storing electricity with the voltage generated from the conversion phenomenon of ferromagnetic resonance (FMR) using an ultra-thin magnetic film of several tens of nanometers.
The research was conducted under the leadership of Prof. Eiji Shikoh. “We are interested in efficiently using the Earth’s natural resources to harvest energy,” states the professor, “and capturing the energy from electromagnetic waves that surround us through the electromotive force (EMF) they generate in magnetic films under FMR shows potential as one such way.” Their research was published in the journal AIP Advances.
Ferromagnetic resonance is a state in which applying electromagnetic waves and an electrostatic magnetic field to a magnetic media causes the electromagnets inside the media to undergo precession at the same frequency as that of the electromagnetic waves. As a technique, it is often used to probe the magnetic properties of a variety of media, from bulk ferromagnetic materials to nano-scale magnetic thin films.
“Research has shown that an EMF is generated in a ferromagnetic metal (FM) that is under FMR,” states Yuta Nogi, first author of the study, “and we explored energy storage possibilities using two FMs that are highly durable, well understood, and thus commonly used in FMR research — an iron-nickel (Ni80Fe20) and iron-cobalt (Co50Fe50) alloy thin film.”
First, the team confirmed the two alloy films generated electricity under ferromagnetic resonance and found that Ni80Fe20 generated about 28 microvolts while Co50Fe50 generated about 6 microvolts of electricity. To store the electricity, they used an electron spin resonance device to pressurize the electromagnetic wave, and the electromagnet of the device for the static magnetic field. Connecting a storage battery directly to the membrane of the sample via a conductor, the team observed that both FM samples successfully stored energy after being in a state of FMR for 30 minutes. However, as the resonance time extended, the amount of energy stored with the iron-nickel alloy film did not change while the iron-cobalt alloy film saw a steady increase.
“This is due to the respective magnetic field ranges for the FMR excitation,” concludes Prof. Shikoh. Upon investigating the different energy storage characteristics of the thin films, the team found when they were in the same thermal states during the experiments, Co50Fe50 could maintain FMR in a detuned condition, while Ni80Fe20 was outside the FMR excitation range. “By appropriately controlling the thermal conditions of the FM film,” continues the professor, “EMF generation under ferromagnetic resonance can be used as an energy harvesting technology.”
Another interesting point about this research is that the team focused on EMF generation itself, independent of its origin. This means that as long as the FMR conditions are met, energy can be stored from electromagnetic waves we interact with daily — for example the Wi-Fi at your favorite café.
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Materials provided by Osaka City University. Note: Content may be edited for style and length. More