Graphene could offer a new way to cool tiny chips in phones, computers, and other gadgets.

“You can fit graphene, a very thin, two-dimensional material that can be miniaturized, to cool a hot spot that creates heating problems in your chip,” says Eva Y. Andrei, a physics professor at Rutgers University. “This solution doesn’t have moving parts and it’s quite efficient for cooling.”

As electronics get smaller and more powerful, there’s an increasing need to for chip-cooling solutions. Researcher show in a paper published in the Proceedings of the National Academy of Sciences that using graphene combined with a boron nitride crystal substrate creates a very efficient cooling mechanism.

“We’ve achieved a power factor that is about two times higher than in previous thermoelectric coolers,” says Andrei.

The power factor refers to the effectiveness of active cooling. That’s when an electrical current carries heat away, as shown in this study, while passive cooling is when heat diffuses naturally.

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For many centuries, lead was the favored material for water pipes due to its malleability. However, the health hazards associated with ingesting lead were not fully understood until the late 1900s. Now, with a massive water infrastructure that utilizes lead pipes and instances of corrosion and leaching causing development and neurological effects in young children consuming tainted water, researchers from Washington University in St. Louis are researching the potential impact of replacing lead pipes.

According to the research team, digging up lead pipes to replace them with copper piping would not only be extremely expensive, but potentially dangerous. The team developed a new way to model and track where dislodged lead particles might be transported during the replacement process.

“We all know lead is not safe, it needs to go,” says Pratim Biswas, past ECS member and chair of Energy, Environmental and Chemical Engineering at the School of Engineering & Applied Science. “This is the first comprehensive model that works as a tool to help drinking-water utility companies and others to predict the outcome of an action. If they have the necessary information of a potential action, they can run this model and it can advise them on how best to proceed with a pipe replacement to ensure there are no adverse effects.”

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By: Mike Williams, Rice University

A new type of conductive graphene foam is incredibly tough and can be formed into just about any shape and size.

A chunk of the foam, which is reinforced by carbon nanotubes, can support more than 3,000 times its own weight and easily bounce back to its original height.

The Rice University lab of chemist James Tour tested this new “rebar graphene” as a highly porous, conductive electrode in lithium ion capacitors and found it to be mechanically and chemically stable. The results appear in the journal ACS Applied Materials and Interfaces.

Carbon in the form of atom-thin graphene is among the strongest materials known and is highly conductive; multiwalled carbon nanotubes are widely used as conductive reinforcements in metals, polymers and carbon matrix composites. The Tour lab had already used nanotubes to reinforce two-dimensional sheets of graphene. Extending the concept to macroscale materials made sense, says Tour, a professor of computer science and of materials science and nanoengineering.

“We developed graphene foam, but it wasn’t tough enough for the kind of applications we had in mind, so using carbon nanotubes to reinforce it was a natural next step,” Tour adds.

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New research out of the University of California, Riverside reveals a transparent, self-healing, highly stretchable material that can be electrically activated to power artificial muscles or improve batteries and electronic devices.

The researchers behind the development believe that this new material could be used to extend the lifetime of lithium-ion batteries in electric vehicles, improve medical and environmental biosensors, and even allow robots to self-heal after mechanical failure.

“Creating a material with all these properties has been a puzzle for years,” says Chao Wang, co-author of the recently published research. “We did that and now are just beginning to explore the applications.”

According to the research, the low-cost material can stretch 50 times its original length and can complete heal in 24 hours after being cut.

Corrosion is a dangerous and extremely costly problem. Because of it, buildings and bridges can collapse, oil pipelines break, and water sources become contaminated. Currently, the global cost estimated to repair corrosive effects comes in around $2.5 trillion per year.

But researchers in the field of corrosion science and technology like Robert Kelly, the 2016 winner of ECS’s Corrosion Division H. H. Uhlig Award, are looking to change the way we deal with the effects of corrosion from reactive to predictive.

“One of the sayings about corrosion is that we can explain everything and predict nothing,” Kelly says. “We’re looking to turn that around.”

Corrosion time machine

Kelly, AT&T Professor of Engineering in the University of Virginia’s Department of Materials Science and Engineering, is working with his team to better understand what’s controlling the localized corrosion process with a newly designed accelerated test that can predict the corrosive effects on certain materials when they’re put into their natural environment.

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Researchers are shedding new light on cell biology with the development of a graphene sensor to monitor changes in the mitochondria.

The one-atom-thin layer of carbon sensor is giving researchers a new outlook into the process known as programmed cell death in mitochondria. The mitochondrion, which is found in most cells, has been known as the powerhouse of the cell due to its ability to metabolize and create energy for cells. However, the new researcher out of University of California, Irving shows that that convention wisdom on how cells create energy is only half right.

This from UC Irving:

[Peter] Burke and his colleagues tethered about 10,000 purified mitochondria, separated from their cells, to a graphene sensor via antibodies capable of recognizing a protein in their outer membranes. The graphene’s qualities allowed it to function as a dual-mode sensor; its exceptional electrical sensitivity let researchers gauge fluctuations in the acidity levels surrounding the mitochondria, while its optical transparency enabled the use of fluorescent dyes for the staining and visualization of voltage across the inner mitochondrial membranes.

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Over the past few years, researchers have been exploring graphene’s amazing properties and vast potential applications. Now, a team from Iowa State University is looking to take those properties enabled by graphene and applied them to sensors and other technologies.

Many scientists have had a hard time moving graphene from the lab to the marketplace, but the research team from Iowa State University saw potential in using inkjet printers to create multi-layer graphene circuits and electrodes for the production of flexible, wearable electronics.

“Could we make graphene at scales large enough for glucose sensors?” ECS member and Iowa State University postdoctoral researcher, Suprem Das, wanted to know.

(MORE: Read more of Das’ work in the ECS Digital Library.)

The problem with the printing process is that the graphene would then have to be treated to improve its electrical conductivity, which could degrade the flexibility. Instead of using high temperatures and chemical to do this treatment, Das and other members of the team opted to use lasers.

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New materials can change their appearance and quickly revert to their original state, taking inspiration from squid and jellyfish.

Researchers believe the materials could have applications in smart windows (allowing users to block light with the push of a button), display optics, and encryption technology.

“There are several marine animals that can very smartly and actively alter their skin’s structure and color,” says Luyi Sun, co-author of the study. “In this work, we follow two examples, squid and jellyfish respectively, to create different mechanical responsive devices.”

This from the University of Connecticut:

They began with a thin, rigid film, and then attached a thicker layer of soft, stretchable elastomer. When the layers are joined and stretched, the rigid layer develops cracks and folds. As this layer is stretched, the cracks and folds grow in size in proportion to the force exerted. As a result, the surface becomes rough and scatters the light that passes through, thereby changing the material’s transparency.

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ECS member and director of the Princeton Institute for Science and Technology of Materials (PRISM), Craig Arnold, recently sat down with Princeton University to discuss the current and future potential of materials science.

Arnold and his research group at Princeton focus on materials processing and fabrication, with applications in energy, optoelectronics, sensing, and nanotechnology. Applications of this research touches the frontiers of technology, pushing boundaries on optimizing grid level storage for alternative energy and cutting-edge optical devices.

In the interview, Arnold discusses core components of materials science, his favorite materials, and explains how materials science has become the bass player in the band.

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Carbon nanotubes have a potentially wide variety of applications due to their strength, flexibility, and other promising properties. While many researchers have been focused on applying carbon nanotubes in nanotechnology and electronics, ECS members Kris Dahl and Mohammad Islam are looking to give the nanotubes a new use in medical applications.

Dahl, a chemical and biomedical engineer; and Islam, a materials scientists; are taking their respective skills and putting them to use in the novel interdisciplinary development, making possible carbon nanotubed-based structures for drug delivery.

This from Carnegie Mellon University:

Picture feeding a dog a pill. In order to do so, one would wrap it in cheese to mask the medicine and make it more appealing. In a similar vein, to enhance drug delivery, Dahl and Islam have engineered proteins that wrap around the drug-coated carbon nanotubes. The cells, which love these proteins, more readily take up the drug—much as a dog would more readily eat the cheese-coated pill.

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