VCU researcher receives NSF grant to extend lifespan of Li-ion batteries, make them more environmentally friendly

Arunkumar Subramanian, Ph.D., an assistant professor in the Department of Mechanical and Nuclear Engineering in the School of Engineering, will use the grant to deliver technological advances that reduce the cost and carbon footprint of Li-ion batteries by extending their lifespan.

A Virginia Commonwealth University professor has received a five-year, $505,000 award from the National Science Foundation to make lithium-ion batteries — which power electric vehicles and portable electronic devices — far more efficient, sustainable and environmentally friendly.

Arunkumar Subramanian, Ph.D., an assistant professor in the Department of Mechanical and Nuclear Engineering in the School of Engineering, will use the grant to deliver technological advances that reduce the cost and carbon footprint of Li-ion batteries by extending their lifespan. He will simultaneously research alternative battery materials that are both nontoxic and more abundant.

"If you look at electrical energy storage solutions that are used in today's electric vehicles and portable electronic devices, you would find that lithium-ion batteries is the technology of choice," Subramanian said. "But if you want to make this technology truly sustainable and environmentally benign, then we need to be able to reduce its cost, as well as its carbon footprint as compared to energy derived from other sources such as fossil fuels."

Subramanian plans to address these goals by extending the lifespan of Li-ion batteries made from sustainable electrode materials, which are derived from the nontoxic manganese oxide material system.

“This project is likely to result in transformative innovations for the battery industry, which in turn will impact a whole host of consumer devices and cars.”

"This project is likely to result in transformative innovations for the battery industry, which in turn will impact a whole host of consumer devices and cars," said Ram Gupta, Ph.D., a professor and associate dean for research in the School of Engineering.

An overarching goal of the project, "Sustainable Solutions for Li-ion Batteries through Cycle-Life Improvements in Nanostructured, 'Green' Cathodes," is to maximize the environmental benefits of electric cars.

"Electric vehicles are one alternative for reducing fossil fuel consumption and greenhouse gas production for sustainable transportation needs," according to the project's abstract. "Electric vehicles require rechargeable batteries that balance the electrical energy storage and power delivery needs, and these batteries must have a lifespan sufficient to reduce cost and achieve true carbon footprint reduction. Furthermore, batteries should be manufactured from sustainable materials to minimize environmental impact."

The award is from National Science Foundation's Faculty Early Career Development (CAREER) Program, which provides the foundation's most prestigious awards in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education and the integration of education and research within the context of the mission of their organizations.

A key aspect of Subramanian's project will be to create batteries in which the team will isolate a single manganese oxide nanowire as the battery's functional electrode element. These nanowire materials are synthesized and supplied by Ekaterina Pomerantseva, Ph.D., a research collaborator and materials science professor at Drexel University.

"Now, the reason we want to do this with nanomaterials is because the small form-factors have the potential to facilitate high charge-storage capacities at fast battery charging and discharging rates,” Subramanian said. “The use of a single nanowire battery electrode is motivated by its ability to reveal the electrochemically correlated structure-property-performance relationships in the material system with atomic-to-nanoscale scale resolution, thereby enabling the optimization of the host crystal to lithium intercalation."

The "nanowires" are one-dimensional constructs that have a diameter of roughly 10 nanometers to 20 nanometers. A nanometer is one billionth of a meter.

"If you were to compare these nanowires to, say, a human hair, [the hair would be] about 10,000 times larger than these nanowires in diameter," Subramanian said.

“If you were to compare these nanowires to, say, a human hair, [the hair would be] about 10,000 times larger than these nanowires in diameter.”

These nanowire electrodes will be tested using a co-integrated device created on silicon chips, which includes a lithium cell and a nanoelectromechanical resonator for charge capacity measurements. The functional components of this device are contained within an ultra-small footprint of a square micron, representing the current state-of-the-art for nanosystems made from synthetic constructs.

Much of the testing with the devices is being conducted at Nanomaterials Core Characterization Facility, a research core facility of the VCU Office of Research and located in the Institute for Engineering and Medicine.

As part of the project, Subramanian's team will also develop a "nano energy" workshop for high school teachers taking part in the NanoFellows Institute organized by the MathScience Innovation Center in Richmond.

"We'll have the teachers visit our lab and do hands-on experiments with nano-enabled batteries and then they would take some of these samples for demonstrations in their classrooms during the school year," he said.

The researchers will also implement "nanobot" workshops and summer research internship programs, which are focused on the use of nanorobots inside electron microscopes, targeting Summer Regional Governor’s School student participants at the MathScience Innovation Center.

The researchers will also introduce this "nano energy" module to high school students taking part in the Richmond Area Program for Minorities in Engineering, a nonprofit organization that works to increase diversity in science and engineering.

Source: VCU

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WHACK! Study measures head blows in girls' lacrosse

Trey Crisco invited lacrosse-playing girls to the lab to measure the impact of their blows as they whacked the head of a laboratory dummy — and to evaluate the performance of protective headgear. Credit: Mike Cohea/Brown University

Lacrosse players swing hard, which is why errant stick blows are the leading cause of concussion in girls' and women's lacrosse. In a new study, researchers measured how much the worst blows accelerate the head and how much different kinds of headgear could reduce those accelerations.

Girls' and women's lacrosse is a different game from the version played by males, said Joseph Crisco, the Henry Frederick Lippitt Professor of Orthopaedic Research in the Alpert Medical School of Brown University and a researcher at Rhode Island Hospital. Females wear far less protective equipment than males do, and injuries -- especially severe head injuries -- are comparatively rare. But recently the debate about whether female players should wear headgear has gained prominence.

Coming to blows

The girls delivered peak performance averaging 60 times the acceleration of Earth's gravity (60g) when they struck the headforms with their lacrosse sticks.

"The goal of our study was to answer the question of what types of head accelerations would you see if you were hit in the head with a stick," said Crisco, who used to coach his daughters in girls lacrosse and also sits on the Sports Science and Safety Committee of US Lacrosse, the national governing body of lacrosse.

To conduct the study, published online in the Journal of Applied Biomechanics, Crisco's team asked seven female lacrosse players aged 12 to 14 to deliver at least 36 whacks each, as hard as they possibly could, to various places on two dummy headforms in the lab.

"The kinds of hits recorded were basically aggressive street fights," Crisco said. "They were really whacking at it, every shaft was broken by the end of the study, which would never happen in a game. The goal was just to give US Lacrosse and the manufacturers some baseline information on the types of accelerations they could expect to see in a worst-case scenario."

They used six different sticks, each outfitted with motion capture markers. The headforms had embedded accelerometers. In a second set of experiments the headforms donned one of four different kinds of protective headgear.

On average across 508 successful blows in the first experiment, the girls swung their sticks about 18 miles an hour, enough to complete two revolutions in less than a second. (One of Crisco's prior studies showed, perhaps not surprisingly, that high school and college players swung their sticks even faster). The peak acceleration the girls delivered to the headforms when they struck them with the shafts of their sticks averaged 60 times the acceleration of Earth's gravity (60g).

That's about three times more force than, say, football players with the kind of celebratory head butt that teammates exchange after a big play, Crisco said.

Headgear dampens blows

The second set of experiments examined what effect headgear might have on the girls' harder whacks (those with speeds around 23 miles an hour). Crisco's team measured the accelerations delivered by 20 whacks from the shaft of each volunteer's stick on both the back and the side of each headform. The headforms wore either nothing, a hard-sided men's lacrosse helmet, a rugby scrum cap, mixed martial arts headgear, or soft headgear designed for girls' and women's field hockey and lacrosse.

The average peak accelerations measured on bare headgear were 81.6g for blows to the side and 150.7g for blows to the back. The men's lacrosse helmet brought the average peak acceleration all the way down to 28.2g on the side and 23.1g on the back. The martial arts and girls lacrosse/field hockey headgear each reduced the accelerations significantly as well, but not nearly as much as the men's helmet. The rugby cap failed to reduce acceleration for blows to the side but dampened blows to the back a little better than the martial arts or lacrosse/field hockey gear.

Headgear, therefore, significantly reduced head accelerations. But Crisco cautioned against a run on headgear at the sporting goods store based on the study.

Generally research has shown that helmets do not protect against concussion -- only against skull fractures and traumatic brain injury. Indeed very little data connects accelerations to concussion risk, and individual susceptibility varies widely. Though some research hints at a figure around 100g, only the hard-sided men's helmet brought accelerations for blows to the back significantly below that figure. And in many game situations, given how little other protective equipment female players wear, Crisco said, a hard-sided helmet could easily cause more injuries that it prevents.

"It could actually make the game more aggressive," Crisco said.

Source: Brown University

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CT scans could bolster forensic database to ID unidentified remains

Cranium image reconstructed from CT scans. Credit: North Carolina State University

A study from North Carolina State University finds that data from CT scans can be incorporated into a growing forensic database to help determine the ancestry and sex of unidentified remains. The finding may also have clinical applications for craniofacial surgeons.

"As forensic anthropologists, we can map specific coordinates on a skull and use software that we developed -- called 3D-ID -- to compare those three-dimensional coordinates with a database of biological characteristics," says Dr. Ann Ross, a professor of anthropology at NC State and senior author of a paper describing the work. "That comparison can tell us the ancestry and sex of unidentified remains using only the skull -- which is particularly valuable when dealing with incomplete skeletal remains."

However, the size of the 3D-ID database has been limited by the researchers' access to contemporary skulls that have clearly recorded demographic histories.

To develop a more robust database, Ross and her team launched a study to determine whether it was possible to get good skull coordinate data from living people by examining CT scans.

The University of Pennsylvania Museum's Morton Collection provided the NC State researchers with CT scans of 48 skulls. Researchers mapped the coordinates of the actual skulls manually using a digitizer, or electronic stylus. Then they compared the data from the CT scans with the data from the manual mapping of the skulls.

The researchers found that eight bilateral coordinates on the skull -- those found on either side of the head -- were consistent for both the CT scans and manual mapping.

"This will allow us to significantly expand the 3D-ID database," Ross says. "And these bilateral coordinates give important clues to ancestry, because they include cheekbones and other facial characteristics."

However, the five midline coordinates the researchers tested showed inconsistencies between the CT scans and manual mapping. Midline coordinates are those found along the center of the skull, such as the bridge of the nose.

"More research is needed to determine what causes these inconsistencies, and whether we'll be able to retrieve accurate midline data from CT scans," says Amanda Hale, a former master's student at NC State and lead author of the paper.

This research may also help craniofacial surgeons. "An improved understanding of the flaws in how CT scans map skull features could help surgeons more accurately map landmarks for reconstructive surgery," Hale says.

Source: North Carolina State University

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Smart window that tints and powers itself invented

NTU Prof Sun Xiaowei holding his smart window invention that can self-tint and also functions as a battery. Credit: Image courtesy of Nanyang Technological University

Nanyang Technological University (NTU) scientists have developed a smart window which can darken or brighten without the need for an external power source.

This unique self-tinting window requires zero electricity to operate and is also a rechargeable battery. The window's stored energy can be used for other purposes, such as to light up low-powered electronics like a light emitting diode (LED).

Currently, the window solutions in the market are either using permanent tinting which cannot brighten at night or are windows that can change its light transmission properties only with an external power source.

The NTU smart window however can be turned into a cool blue tint in bright daylight, cutting light penetration by about half, and then reverts back to clear glass at night or as required.

This breakthrough research led by NTU Professor Sun Xiaowei, was published recently in Nature Communications.

How it works

The trick to making the self-powered smart window is a new technology developed by Prof Sun's team from NTU's School of Electrical and Electronic Engineering.

"Our new smart electrochromic window is bi-functional; it is also a transparent battery," Prof Sun explained. "It charges up and turns blue when there is oxygen present in the electrolyte -- in other words, it breathes."

The NTU smart window contains liquid electrolyte placed in between two glass sheets coated with indium tin oxide (ITO), commonly used as transparent conductive coatings for television displays. One sheet is coated with an additional layer of a pigment known as Prussian Blue and the other one is attached to a thin strip of aluminium foil. The Prussian Blue gives the glass a blue tint when it is fully charged.

The two glass sheets are connected by typical electrical cables. When the electrical circuit between them is broken, a chemical reaction starts between Prussian Blue and the dissolved oxygen in the electrolyte, turning the glass blue. To turn off the blue tint, the electrical circuit is closed to discharge the battery, turning the Prussian Blue into a colourless Prussian White.

Such an innovative technology can adjust the amount of sunlight coming into buildings in the day, which promises significant savings on cooling and lighting costs.

"Our technology is very attractive as a zero-sum consumption smart window. Buildings owners and even common households can reap energy savings right from the outset and over the long term. Developers who are looking at constructing environmentally-friendly green buildings will find our technology attractive for their building plans," said Prof Sun.

Prof Sun is an electrical engineering expert whose other innovations include various solar technologies, glass-free 3D technologies, next-generation lightings and displays.

The NTU team, consisting of five researchers, is now enhancing their invention and is looking forward to collaborating with industry partners to commercialise their technology.

Source: Nanyang Technological University

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'Grimsel' electric racing car breaks world record

The record journey from the car driver's perspective. Credit: AMZ Racing

The 'grimsel' electric racing car today broke the previous world record for acceleration in electric cars. The vehicle accelerated from 0 to 100 km/h in 1.79 seconds in under 30 metres. The new record was set by students from ETH Zurich and Lucerne University of Applied Sciences and Arts, who also designed and built the vehicle.

The Formula Student team at the Academic Motorsports Club Zurich (AMZ) finally did it: its 'grimsel' electric racing car smashed the previous world record when it accelerated from 0 to 100 km/h in just 1.785 seconds. The previous record of 2.134 seconds was held by an electric car built by Delft University of Technology. The new record was set at the military airfield in Dübendorf, where the vehicle reached a speed of 100 km per hour in less than 30 metres.

The new record-breaking vehicle is a Formula Student electric car that was developed and built in less than a year by 30 students at ETH Zurich and Lucerne University of Applied Sciences and Arts. The 'grimsel' is the fifth AMZ electric car and the result of continuous development. The carbon fibre construction has a total weight of 168 kg and produces about 200 hp. A four-wheel drive is implemented with four specially designed wheel hub motors, which generate a total torque of 1630 Nm at the wheels. By means of traction control, torque distribution is controlled individually for each wheel to maximise vehicle acceleration. No other production vehicle in the world has reached a similarly strong acceleration.

AMZ's most successful car

The 'grimsel' celebrated numerous successes at the Formula Student international competition this summer. With more than 500 teams, Formula Student is the world's biggest competition for engineers and is held annually at various locations around the globe. With three overall wins and an average of 920 points out of a possible 1,000, the 'grimsel' is AMZ's most successful car. And with its victories in Austria and Spain, it achieved the two highest scores in the European history of Formula Student. These further strengthened AMZ's standing at the top of the Formula Student world rankings and demonstrated the potential in electric drive concepts.

Source: ETH Zürich

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Playing action video games can boost learning, study finds

A new study shows for the first time that playing action video games improves not just the skills taught in the game, but learning capabilities more generally.

A new study shows for the first time that playing action video games improves not just the skills taught in the game, but learning capabilities more generally.

"Prior research by our group and others has shown that action gamers excel at many tasks. In this new study, we show they excel because they are better learners," explained Daphne Bavelier, a research professor in brain and cognitive sciences at the University of Rochester. "And they become better learners," she said, "by playing the fast-paced action games."

According to Bavelier, who also holds a joint appointment at the University of Geneva, our brains keep predicting what will come next -- whether when listening to a conversation, driving, or even preforming surgery. "In order to sharpen its prediction skills, our brains constantly build models, or 'templates,' of the world," she explained. "The better the template, the better the performance. And now we know playing action video game actually fosters better templates."

Action Players vs. Non-Action Players

In the current study, published in the Proceedings of the National Academy of Sciences, Bavelier and her team first used a pattern discrimination task to compare action video game players' visual performance with that of individuals who do not play action video games.
The action-gamers outperformed the non-action gamers. The key to the action-gamers success, the researchers found, was that their brains used a better template for the task at 
hand.

Video Training

Then, the team conducted another experiment to determine if habitual players of fast-paced, action-rich video games may be endowed with better templates independently of their game play, or if the action game play lead them to have better templates.

Individuals with little video game experience were recruited, and as part of the experiment, they were asked to play video games for 50 hours over the course of nine weeks. One group played action video games, e.g., Call of Duty. The second group played 50 hours of non-action video games, such as The Sims.

The trainees were tested on a pattern discrimination task before and after the video game "training." The test showed that the action video games players improved their templates, compared to the control group who played the non-action video games. The authors then turned to neural modeling to investigate how action video games may foster better templates.

Measuring Learning

When the researchers gave action gamers a perceptual learning task, the team found that the action video game players were able to build and fine tune templates quicker than non-action game control participants. And they did so on the fly as they engaged in the task.
Being a better learner means developing the right templates faster and thus better performance. And playing action video games, the research team found boosts that process.
"When they began the perceptual learning task, action video gamers were indistinguishable from non-action gamers; they didn't come to the task with a better template," said Bavelier. "Instead, they developed better templates for the task, much, much faster showing an accelerated learning curve."

The researchers also found that the action gamers' improved performance is a lasting effect. When tested several months to a year later, the action-trained participants still outperformed the other participants, suggesting that they retained their ability to build better templates.

Bavelier's team is currently investigating which characteristics in action video games are key to boost players' learning. "Games other than action video games may be able to have the same effect," she said. "They may need to be fast paced, and require the player to divide his or her attention, and make predictions at different time scales."

Vikranth R. Bejjanki of the University of Rochester and Princeton University, and Ruyuan Zhang of the University of Rochester are co-lead authors of the study. In addition to Bavelier and the lead authors, researchers from the University of Geneva, University of Wisconsin-Madison, and Ohio State University also contributed to the study.

The Office of Naval Research, the Swiss National Foundation, The Human Frontier Science Program, and the National Eye Institute supported the research.

Source: University of Rochester

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Electric eels deliver taser-like shocks

News research has discovered that the electric eel delivers Taser-like shocks. Credit: Kenneth Catania, Vanderbilt University

The electric eel -- the scaleless Amazonian fish that can deliver an electrical jolt strong enough to knock down a full-grown horse -- possesses an electroshock system uncannily similar to a Taser.

That is the conclusion of a nine-month study of the way in which the electric eel uses high-voltage electrical discharges to locate and incapacitate its prey. The research was conducted by Vanderbilt University Stevenson Professor of Biological Sciences Kenneth Catania and is described in the article "The shocking predatory strike of the electric eel" published in the Dec. 5 issue of the journal Science.

People have known about electric fish for a long time. The ancient Egyptians used an electric marine ray to treat epilepsy. Michael Faraday used eels to investigate the nature of electricity and eel anatomy helped inspire Volta to create the first battery. Biologists have determined that a six-foot electric eel can generate about 600 volts of electricity -- five times that of a U.S. electrical outlet. This summer scientists at the University of Wisconsin-Madison announced that they had sequenced the complete electric eel genome.

Until now, however, no one had figured out how the eel's electroshock system actually worked. In order to do so, Catania equipped a large aquarium with a system that can detect the eel's electric signals and obtained several eels, ranging up to four feet in length.

As he began observing the eels' behavior, the biologist discovered that their movements are incredibly fast. They can strike and swallow a worm or small fish in about a tenth of a second. So Catania rigged up a high-speed video system that ran at a thousand frames per second so he could study the eel's actions in slow motion.

Catania recorded three different kinds of electrical discharges from the eels: low-voltage pulses for sensing their environment; short sequences of two or three high-voltage millisecond pulses (called doublets or triplets) given off while hunting; and volleys of high-voltage, high-frequency pulses when capturing prey or defending themselves from attack.

He found that the eel begins its attack on free-swimming prey with a high-frequency volley of high-voltage pulses about 10 to 15 milliseconds before it strikes. In the high-speed video, it became apparent that the fish were completely immobilized within three to four milliseconds after the volley hit them. The paralysis was temporary: If the eel didn't immediately capture a fish, it normally regained its mobility after a short period and swam away.

"It's amazing. The eel can totally inactivate its prey in just three milliseconds. The fish are completely paralyzed," said Catania.

These observations raised an obvious question: How do the eels do it? For that, there was no clear answer in the scientific literature.

"I have some friends in law enforcement, so I was familiar with how a Taser works," said Catania. "And I was struck by the similarity between the eel's volley and a Taser discharge. A Taser delivers 19 high-voltage pulses per second while the electric eel produces 400 pulses per second."

The Taser works by overwhelming the nerves that control the muscles in the target's body, causing the muscles to involuntarily contract. To determine if the eel's electrical discharge had the same effect, Catania walled off part of the aquarium with an electrically permeable barrier. He placed a pithed fish on other side of the barrier from the eel and then fed the eel some earthworms, which triggered its electrical volleys. The volleys that passed through the barrier and struck the fish produced strong muscle contractions.

To determine whether the discharges were acting on the prey's motor neurons -- the nerves that control the muscles -- or on the muscles themselves, he placed two pithed fish behind the barrier: one injected with saline solution and other injected with curare, a paralytic agent that targets the nervous system. The muscles of the fish with the saline continued to contract in response to the eel's electrical discharges but the muscle contractions in the fish given the curare disappeared as the drug took effect. This demonstrated that the eel's electrical discharges were acting through the motor neurons just like Taser discharges.

Next Catania turned his attention to the way in which the eel uses electrical signals for hunting. The eel is nocturnal and doesn't have very good eyesight. So it needs other ways to detect hidden prey.

The biologist determined that the closely space doublets and triplets that the eel emits correspond to the electric signal that motor neurons send to muscles to produce an extremely rapid contraction.

"Normally, you or I or any other animal can't cause all of the muscles in our body to contract at the same time. However, that is just what the eel can cause with this signal," Catania said.
Putting together the fact that the eels are extremely sensitive to water movements with the fact that the whole-body muscle contraction causes the prey's body to twitch, creating water movements that the eel can sense, Catania concluded that the eel is using these signals to locate hidden prey.

To test this hypothesis, Catania connected a pithed fish to a stimulator.. He put the fish in a clear plastic bag to protect it from the eel's emissions. He found that when he stimulated the fish to twitch right after the eel emitted one of its signals, the eel would attack. But, when the fish failed to respond to its signal, the eel did not attack. The result supports the idea that the eel uses its electroshock system to force its prey to reveal their location.

"If you take a step back and think about it, what the eel can do is extremely remarkable," said Catania. "It can use its electrical system to take remote control of its prey's body. If a fish is hiding nearby, the eel can force it to twitch, giving away its location, and if the eel is ready to capture a fish, it can paralyze it so it can't escape."

The research was funded by a Pradel Award from the National Academy of Sciences, a Guggenheim fellowship and National Science Foundation grant 0844743.

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Source: Vanderbilt University

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