Why do synthetic 2D materials often perform orders of magnitude worse than predicted? A new understanding of this scenario could improve the materials’ performance in future electronics, photonics, and memory storage.

2D materials are films only an atom or two thick. Researchers make 2D materials by the exfoliation method—peeling a slice of material off a larger bulk material—or by condensing a gas precursor onto a substrate. The former method provides higher-quality materials, but is not useful for making devices. The second method is well established in industrial applications, but yields low performance 2D films.

The researchers demonstrated, for the first time, why the quality of 2D materials grown by the chemical vapor deposition method have poor performance compared to their theoretical predictions. They report their results in Scientific Reports.


ElectronicsA new process for growing wafer-scale 2D crystals could enable future super-thin electronics.

Since the discovery of the remarkable properties of graphene, scientists have increasingly focused research on the many other two-dimensional materials possible, both those found in nature and those concocted in the lab.

Growing high-quality, crystalline 2D materials at scale, however, has proven a significant challenge.

Researchers led by Joan Redwing, director of the National Science Foundation-sponsored Two-Dimensional Crystal Consortium—Materials Innovation Platform, and professor of materials science and engineering and electrical engineering at Penn State, developed a multistep process to make single crystal, atomically thin films of tungsten diselenide across large-area sapphire substrates.


Flexible materialStress a muscle and it gets stronger. Mechanically stress a new rubbery material—say with a twist or a bend—and it automatically stiffens by up to 300 percent, the engineers say.

In lab tests, mechanical stresses transformed a flexible strip of the material into a hard composite that can support 50 times its own weight.

This new composite material doesn’t need outside energy sources such as heat, light, or electricity to change its properties. And it could be used in a variety of ways, including applications in medicine and industry.

The researchers found a simple, low-cost way to produce particles of undercooled metal—that’s metal that remains liquid even below its melting temperature. Researchers created the tiny particles (they’re just 1 to 20 millionths of a meter across) by exposing droplets of melted metal to oxygen, creating an oxidation layer that coats the droplets and stops the liquid metal from turning solid. They also found ways to mix the liquid-metal particles with a rubbery elastomer material without breaking the particles.


National Academy of EngineeringRaymond J. Gorte, Yang Shao-Horn, and M. Stanley Whittingham, all of whom are ECS fellows, were recently elected to the National Academy of Engineering. Election to the NAE is one of the most prestigious professional distinctions bestowed upon engineers.

According to the NAE, academy membership honors individuals who have made outstanding contributions to “engineering research, practice, or education, including, where appropriate, significant contributions to the engineering literature” and to “the pioneering of new and developing fields of technology, making major advancements in traditional fields of engineering, or developing/implementing innovative approaches to engineering education.”


GrapheneAdding a little ultrathin hexagonal boron nitride to ceramics could give them outstanding properties, according to new research.

Rouzbeh Shahsavari, an assistant professor of civil and environmental engineering at Rice University, suggests the incorporation of ultrathin hBN sheets between layers of calcium-silicates would make an interesting bilayer crystal with multifunctional properties.

These could be suitable for construction and refractory materials and applications in the nuclear industry, oil and gas, aerospace, and other areas that require high-performance composites.

Combining the materials would make a ceramic that’s not only tough and durable but resistant to heat and radiation. By Shahsavari’s calculations, calcium-silicates with inserted layers of two-dimensional hBN could be hardened enough to serve as shielding in nuclear applications like power plants.


Carbon dioxide Scientists have found a way to make their asphalt-based sorbents better at capturing carbon dioxide from gas wells: Adding water.

The lab of chemist James Tour, a chair in chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice University, discovered that treating grains of inexpensive Gilsonite asphalt with water allows the material to adsorb more than two times its weight in the greenhouse gas. The treated asphalt selects carbon dioxide over valuable methane at a ratio of more than 200-to-1.

The material performs well at ambient temperatures and under the pressures typically found at wellheads. When the pressure abates, the material releases the carbon dioxide, which can then be stored, sold for other industrial uses, or pumped back downhole.

Natural gas at the wellhead typically contains between 3 and 7 percent carbon dioxide, but at some locations may contain up to 70 percent. Oil and gas producers traditionally use one of two strategies to sequester carbon dioxide: physically through the use of membranes or solid sorbents like zeolites or porous carbons, or chemically through filtering with liquid amine, a derivative of ammonia.


PhotosynthesisResearchers have traced the paths of three water channels in an ancient photosynthetic organism—a strain of cyanobacteria—to provide the first comprehensive, experimental study of how that organism uses and regulates water to create energy.

The finding advances photosynthesis research but also presents an advance in green fuels research.

Photosynthesis is the chemical conversion of sunlight into chemical energy via an electron transport chain essential to nearly all life on our planet. All plants operate by photosynthesis, as do algae and certain varieties of bacteria.

‘Damage trails’

To convert sunlight into a usable form of energy, photosynthetic organisms require water at the “active site” of the Photosystem II protein complex. But the channels through which water arrives at the active site are difficult to measure experimentally. Reactive oxygen species are produced at the active site and travel away from it, in the opposite direction as water, leaving a “damage trail” in their wake.

“We identified the damaged sites in Photosystem II using high-resolution mass spectrometry and found that they reveal several pathways centered on the active site and leading away from it all the way to the surface of the complex,” says lead study author Daniel A. Weisz, a postdoctoral researcher in biology at Washington University in St. Louis.


GraphenePillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, report engineers.

Materials scientist Rouzbeh Shahsavari of Rice University and alumnus Navid Sakhavand first built atom-level computer models of pillared graphene—sheets of graphene connected by covalently bonded carbon nanotubes—to discover their strength and electrical properties as well as their thermal conductivity.

In a new study, they found that manipulating the joints between the nanotubes and graphene has a significant impact on the material’s ability to direct heat. That could be important as electronic devices shrink and require more sophisticated heat sinks.


A reversible fabric keeps skin a comfortable temperature whatever the weather—and could save energy by keeping us away from the thermostat.

As reported in Science Advances, the double-sided fabric is based on the same material as everyday kitchen wrap and can offer warmth or cooling depending on which side faces out.

“Why do you need to cool and heat the whole building? Why don’t you cool and heat individual people?” says Yi Cui, professor of materials science and engineering at Stanford University, who thought if people could be more comfortable in a range of temperatures, they could save energy on air conditioning and central heating.

Thirteen percent of all of the energy consumed in the United States is due to indoor temperature control. But for every 1 degree Celsius (1.8 degrees Fahrenheit) that a thermostat is turned down, a building can save a whopping 10 percent of its heating energy—and the reverse is true for cooling. So adjusting temperature controls by just a few degrees could have major effects on energy consumption.


Researchers have developed a type of “smart paper” that can conduct electricity and detect water.

The paper, laced with conductive nanomaterials, can be employed as a switch, turning on or off an LED light, or as an alarm system indicating the absence or presence of water.

In cities and large-scale manufacturing plants, a water leak in a complicated network of pipes can take tremendous time and effort to detect, as technicians must disassemble many pieces to locate the problem.

The American Water Works Association indicates that nearly a quarter-million water line breaks occur each year in the United States, costing public water utilities about $2.8 billion annually.

The smart paper could simplify the process for discovering detrimental leaks.


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