Diamond memory, drinkable seawater and energy through the air. This week’s coolest things make the most of the elements.
What is it? Scientists in Japan made a 2-inch-diameter diamond wafer that could store 25 million terabytes of quantum data, theoretically enough to record a billion Blu-ray discs.
Why does it matter? Diamond could be a very useful material for quantum computing and memory storage. But so far, researchers have been able to produce only 4-millimeter wafers of the necessary purity, while industrial uses require wafers of at least 2 inches — 14 times larger.
How does it work? Although diamond is a form of carbon, its ability to store information comes from nitrogen, a common impurity. In particular, scientists take advantage of a defect called nitrogen-vacancy center, where a nitrogen atom sits next to an empty space in the crystal lattice. A little nitrogen goes a long way, and too much is problematic. It’s a difficult balance to strike, and researchers have failed to make industrial-size wafers without an excess of nitrogen. The scientists, from Saga University and Adamant Namiki Precision Jewel Co., devised a new method for creating the diamond wafers by growing crystals on a stepped substrate surface instead of a flat one. That reduced strain on the material, resulting in improved quality and limiting nitrogen contamination to a minuscule 3 parts per billion. “This new technology is expected to propel the advancement of quantum applications,” Adamant Namiki said in a statement. The company plans to commercialize the product in 2023.
Top and above: Engineers were able to send microwave power more than 1 kilometer to a dish antenna. Scaled up, this technology could enable energy to be delivered from space to troops on the ground. Image and video credits: Naval Research Laboratory.
What is it? Scientists from the Naval Research Laboratory wirelessly beamed 1.6 kilowatts (kW) of electrical energy across more than 1 kilometer (km).
Why does it matter? The Pentagon tasked NRL researchers with demonstrating the delivery of 1 kW of power at a distance of 1 km, explained principal investigator Chris Rodenbeck. The test showed the possibility of sending electricity power to remote locations, such as on-the-ground military operations. In the long run, the technology could be used to deliver energy from space to Earth.
How does it work? Engineers generated electricity, converted it to a 10-gigahertz microwave beam, and sent it through a dish antenna aimed at a receiver more than a kilometer away. The receiver consisted of a highway-sign-size array of tens of thousands of antennas working in what’s known as the X-band frequency (commonly used for police speed radar guns). Diodes converted the microwave power into DC power.
What is it? Researchers from Virginia Tech and the U.S. Department of Energy homed in on an unappreciated factor in what causes batteries to decay.
Why does it matter? Rechargeable batteries degrade over time. The research team discovered that it’s not just the properties of the electrode particles that cause decay, but also the interactions between them. “If you want to build a better battery, you need to look at how to put the particles together,” said Yijin Liu, a senior author of a paper in Science.
How does it work? The researchers used X-ray tomography to create 3D images of battery cathodes at different ages. They identified more than 2,000 particles and described their size, shape and surface roughness, as well as how often they came into contact with one another. They found that after 10 charging cycles, traits such as surface-to-volume ratio and roundness of particles contributed most to their decay. But after 50 charging cycles, breakdown was driven primarily by interactions between particles, including how far apart they were, how varied their shapes and whether they were oriented similarly. Manufacturers could account for these particle-particle interactions to design longer-lasting batteries.
What is it? Tufts University neuroscientists discovered a previously unknown ability of astrocytes, which make up nearly half of all brain cells.
Why does it matter? Scientists knew that astrocytes were important in helping neurons grow and transmit signals in the brain. The research could open ways to attack ailments like epilepsy and Alzheimer’s.
How does it work? The team programmed mice with genetically encoded voltage indicators that allowed them to visualize electrical activity with light. The study showed for the first time that astrocytes are electrically active, like neurons, and that the two cell types affect each other’s activity. “Neurons and astrocytes talk with each other in a way that has not been known about before,” said Chris Dulla, an author on a paper in Nature Neuroscience. Because there is so much that is not known about how the brain works, he added, discovering new fundamental processes that control brain function is key to developing novel treatments for neurological diseases.
This portable unit, which weighs less than 22 pounds and does not require the use of filters, can be powered by a small, portable solar panel. Image credit: Video credit: MIT.
What is it? MIT researchers developed a portable, filter-free desalination system the size of a small suitcase.
Why does it matter? Portable devices for purifying water typically require a steady supply of energy to pump water through filters that need to be periodically replaced. At a mere 20 pounds, the new system, described in Environmental Science and Technology, eliminates filters and needs only as much energy as a phone charger.
How does it work? The device uses a low-power pump to run water between two charged membranes that attract or repel particles such as salt ions, bacteria and viruses. Then it uses electrodialysis to remove any remaining salt. “It was successful even in its first run, which was quite exciting and surprising. But I think the main reason we were successful is the accumulation of all these little advances that we made along the way,” said senior author Jongyoon Han.