A satellite phased-array transceiver that folds up for launch and unfolds in space has been shown to work successfully in orbit, as reported by researchers from Science Tokyo. By using an innovative approach to correct nonplanar deformations in the deployable membrane antenna, this work lays the foundation for satellite constellation-based wireless communications in the Beyond 5G and 6G era.
A new stretchablequantum-dot light-emitting diode (QLED) delivers incredibly high resolution while producing record brightness that can be clearly viewed even outside in direct sunlight.
In a recent paper published in Nature Nanotechnology, Korean researchers unveiled a new QLED material with applications far beyond televisions, stretching into many future daily-use technologies.
This new QLED can stretch in every direction, just like organic skin, making it extremely useful in future wearable applications and as a covering for soft robots. Unlike earlier attempts to make a stretchable QLED, this one doesn’t lose picture quality when it stretches, delivering high resolution and extreme brightness under tension.
QLED Explained
For most of us, QLEDs are familiar as one of the technologies available in modern televisions. Conventional QLED TVs use quantum dots—nanoscale semiconductor crystals—to help produce exceptionally bright and vivid colors. OLED displays, by comparison, use self-emissive pixels that can switch off individually, allowing them to produce deeper blacks. While OLEDs perform particularly well in dark viewing environments, the high brightness achievable with quantum-dot displays can make them especially well-suited for brightly lit environments.
Despite the technology’s suitability for the bright world around us rather than just darkened environments, major challenges remained in producing a stretchable version. Early attempts addressed the problem by allowing the wiring to stretch while the light-emitting pixels remained unchanged in size. This meant that as the material expanded, its effective resolution dropped because the same number of pixels became spread across a wider area, much like enlarging a low-resolution digital image.
Building on these efforts, some researchers attempted to replace conventional materials with more stretchable alternatives, but these tended to make achieving high resolutions and efficiently moving electrical charge through the material difficult. As a result, these systems produced dimmer, lower-resolution images, limiting their utility.
A New Process
The researchers developed a new fabrication approach to address some of the major problems facing stretchable QLED technology. Central to their innovation is the use of an elastic polymer incorporating MPA as a ligand, or bonding molecule. This approach improves charge injection efficiency while helping eliminate the image stretching and smearing that have affected previous stretchable displays.
Using this new process, the researchers produced a display with a resolution of about 16,000 pixels per inch, with features spaced at roughly 700 nanometers. Red, green, and blue emissive layers can also be precisely arranged, allowing the stretchable material to produce full-color images.
Testing a New QLED
In tests, the team’s new QLED proved to be a major advance. They successfully stretched the material to 1.65 times its original size with no damage to its light-emitting performance. Additionally, their stretchable QLEDs were the brightest ever tested at 53,300 nits, more than triple the brilliance of prior attempts.
Based on these tests, the researchers see numerous future applications for their material in extended reality devices, soft robots, electronic skin, wearable technologies, health care, and automotive displays.
“We resolved both the drop in resolution and the limits on light-emitting performance, which had been the biggest challenges for stretchable displays, and secured core technology for commercialization,” concluded co-author Professor Moon Kee Choi of Ulsan National Institute of Science and Technology in Korea. “It will be used widely as a manufacturing platform for various next-generation soft devices, including wearables and electronic skin.”
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.
Scientists have developed a low-cost device that can continuously check air ducts at nuclear facilities for traces of radioactive material. The detector, created at the U.S. Department of Energy’s Oak Ridge National Laboratory, or ORNL, can take measurements once a minute when running on a battery. When connected through an Ethernet cable, it can collect […]
Scientists have developed a new way to make an extremely strong metal-based material much less likely to break when it is bent or squeezed. The discovery could eventually lead to tougher materials for aircraft engines, turbines, energy systems and other machines that operate under extreme conditions. The research was led by engineers at Purdue University […]
Corrosion is a major concern for aging steel bridges because progressive material loss can affect their long-term serviceability and, in severe cases, structural safety. Visual inspection remains indispensable for assessing bridge condition, but inspectors must evaluate corrosion under widely varying conditions, including differences in lighting, coating color, shadows, surface deposits, structural geometry and accessibility. These factors can make consistent corrosion assessment challenging.
Researchers at the Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) developed a new type of monitor that can check every minute or even every second for the buildup of nuclear material in the air ducts of nuclear fuel cycle facilities, promoting high standards of safety and security.
Scientists have used an X-ray detector on a sounding rocket, a type of research rocket that flies to the edge of space, then returns to Earth within minutes, to document metal dendrites—the branching structures that form as liquid metal cools—forming in microgravity conditions for the first time. By analyzing the images using machine learning, they reveal insights that could improve how metal components are solidified and manufactured.
Radar technology is one of the most powerful tools for better understanding the world around us. Researchers use radar to see beneath the surface of ice, forest canopies or soil in ways the human eye never could. As the planet changes, that capability matters more than ever.
Today’s chatbots aren’t likely to help lone actors invent a deadly pathogen, experts say. But newer models, trained in biology, may need stronger safeguards.
Billions of people still suffer from hunger and food insecurity worldwide. Meanwhile, microbial contamination causes a third of global food waste annually, resulting in major economic losses and illnesses. Although antibiotics and pesticides help control contamination, their excessive use can promote bacterial resistance or leave toxic residues.
One alternative uses materials that generate highly reactive forms of oxygen when exposed to light, called photocatalysts, to prolong food freshness. These molecules kill bacteria by damaging their cell components in a process called photodynamic inactivation or PDI. However, current PDI systems rely on energy-intensive lasers and long exposure times because the bacteria’s protective cell membranes block reactive oxygen molecules. As a result, the systems don’t kill bacteria effectively and risk overheating food, affecting its freshness and nutritional value.
Scientists at Zhejiang University in China thought that it would be possible to achieve a PDI system using accessible, free sunlight with the right photocatalyst. Moreover, they also wanted to integrate this photocatalyst into food packaging to combat microbes during storage.
To make the photocatalyst, the researchers mixed water with a glue-like plant fiber that provides structural support, called pectin, and a chemical from plant seeds that supplies phosphorus, called phytic acid. Then they heated the mixture in a sealed reactor at 220ºC (428ºF) for 5 hours to form tiny structures composed of a carbon core surrounded by a phosphorus-rich shell called phosphorus-modified carbonized polymer dots or PCDs.
To incorporate the PCDs into film packaging, the researchers dissolved equal amounts of a plant fiber from konjac, called glucomannan,and another plant-derived molecule, called carboxymethylcellulose, in warm water to form a network of entangled molecular chains. Then, they added 1.5 milligrams of PCD per milliliter to this mixture, which linked the chains together like molecular fasteners. Finally, they added a moisture-binding chemical called glycerin to prevent brittleness. The researchers cast this mixture onto separate Petri dishes and dried them, forming thin, plastic-like PCD films.
To test the films, the researchers placed Escherichia coli bacteria between 2 sterilized film sheets and exposed the samples to either darkness or simulated sunlight for 20 minutes. They then transferred the microbes onto agar plates and incubated them for 15 hours, allowing surviving bacteria to form visible colonies. They compared the number of bacterial colonies with those of untreated samples to calculate the percentage of bacteria the films eliminated in each environment.
Tests under darkness showed that the films eliminated about 60% of the bacteria. The researchers attributed this result to the positive electrical charge of PCDs, which attracts the bacteria’s negatively charged cell surfaces. The electrical attraction stresses their cell membranes, interfering with essential life processes. This result suggested that the films use a separate charge-based antibacterial mechanism apart from PDI, which requires light to work.
Under simulated sunlight, the films eliminated nearly 100% of the bacteria. The researchers identified 2 principal mechanisms causing this. First, the PCDs acted as tiny heaters that generated localized heat, which stretched holes in the bacterial membranes, allowing contents to leak out of their cells through a process called photoporation. Second, the PCDs generated reactive oxygen molecules that could then penetrate the bacteria. Once inside the cells, these molecules irreversibly damage the bacteria’s internal components and genetic material through PDI.
The researchers also investigated whether PCD films could serve as food packaging by using them to wrap fresh strawberries. Compared with conventional nonbiodegradable polyethylene packaging where visible rotting occurred, the PCD films kept the strawberries fresh for more than 4 days by suppressing bacterial growth and regulating moisture levels. When the team tested whether the films were toxic, they found that the films are safe for humans and compatible for food applications. They also buried the films in soil for 24 days and found that they degraded by 78%, demonstrating biodegradability suitable for packaging fresh foods.
The team concluded that PCD films could be a biodegradable food packaging that combines plant-based materials with multiple antibacterial strategies. The films retained antibacterial activity in darkness and became more effective under sunlight through the combined effects of photoporation and PDI. These findings demonstrated that by combining multiple mechanisms into a single material, researchers can create multifunctional food packaging that remains effective across different storage conditions.
By the time naval architecture firm George G. Sharp tasked Jack Heaney with the design of the world’s first nuclear-powered merchant ship, the Glasgow-born designer had already broken many styling norms. In the mid-1940s, Heaney transformed routine ocean transport into a festive occasion when he designed the interiors of the SS President Wilson and SS President Cleveland with Hawaiian murals, carved glass panels, and a smoking lounge dressed in playful, exotic wall art. His gift for making the mundane desirable wasn’t confined to ocean liners—New York’s Museum of Modern Art had already put one of his stackable aluminum chairs on display in 1947. But nothing in Heaney’s career had prepared him for the commission that reached his drawing board in 1957.
At the time, the shadow of 1945, when the world first witnessed the terrifying power of the atom, loomed large. Following World War II, the United States and Soviet Union were locked in a nuclear arms race, and the public associated splitting atoms with annihilation. Atoms meant war.
To shift that sentiment, President Eisenhower launched his Atoms for Peace initiative, aimed at demonstrating the civilian benefits of nuclear technology—and the NS Savannah, or Nuclear Ship Savannah, was to be its flagship. Heaney suddenly had a much more daunting task than usual; he would have to make the feared desirable.
More than half a century since theSavannah was decommissioned in 1971, there is no nuclear-powered merchant ship in active commercial service anywhere in the world. Four nations have tried. None succeeded, mostly because the economics were not compelling enough and no one trusted nuclear ships.
In the interim, nuclear reactors have only become smaller and safer. Now, as the true cost of burning oil at sea comes due—commercial shipping produces more than three percent of global greenhouse gas emissions—the economics of nuclear-powered merchant ships may finally be compelling. But the problem Heaney was hired to solve in 1957 still stands in the way, persuading people to trust what they fear.
The making of a maritime designer
John “Jack” Heaney was born in Glasgow in 1904. He grew up during a time when the River Clyde, which runs through the heart of Glasgow, served as the world’s premiere shipbuilding hub, with nearly 40 shipyards situated on its banks. Heaney studied naval architecture at the University of Glasgow, while taking classes at the Glasgow School of Art and apprenticing at the Fairfield Shipbuilding and Engineering Company.
When Heaney emigrated to New York in 1926, he worked a string of jobs, including a brief stint as a door-to-door refrigerator salesman, before joining the New York City-based naval architecture firm George G. Sharp, Inc. in 1937. At Sharp, Heaney quickly developed a reputation for having an engineer’s eye and artist’s hand, helping design the interiors of several prominent passenger-cargo ships—a specialized form of merchant ship that is part cruise liner, part cargo vessel—including the Robin Line, the Delta Line, and the American President Lines. In 1947, the same year MoMA put his chair on display, Heaney opened his own design firm on West 54th Street in Manhattan. A decade later, the Savannah project came across his bow.
Originally tasked with the ship’s exterior design, Heaney eventually assumed responsibility for the ship’s interior styling, too. From stem to stern, it was Heaney’s job to design a nuclear-powered ship that passengers would want to cruise on for pleasure, and that businesses would want to ship merchandise on for commerce.
The NS Savannah was the first nuclear-powered merchant ship. Image: Contributor / Getty Images / Mondadori Portfolio
Atoms for Peace
Eisenhower had announced the Atoms for Peace initiative four years earlier, in a December 1953 address to the United Nations. The atom, he argued, should be turned from a great destructive force “into a great boon, for the benefit of all mankind.” Under Eisenhower, the U.S. began sharing reactor technology and medical isotopes with allied nations. Atoms for Peace sought to prove that the technology that had obliterated two cities could also light homes, treat cancer, build harbors, and move ships.
The U.S. Navy, meanwhile, saw the advantages of a vessel that could continuously plow the ocean without refueling for months, or even years. The USS Nautilus was the first atomic-powered vessel, a sub, launching in 1955. By the time Sharp signed Heaney to the Savannah project, two more atomic-powered subs were patrolling the world’s oceans (USS Skate and USS Seawolf). But military vessels primarily keep to military ports, so the public rarely saw them.
Eisenhower needed a civilian showcase that would disassociate atom-splitting from mushroom clouds. That showcase would be Heaney’s NS Savannah. As a passenger-cargo ship, the Savannah would routinely sail into commercial harbors like Rotterdam, Le Havre, and New York, normalizing nuclear reactors and demonstrating their safety. At least, that was the goal.
How safe is our A-ship?
In 1959, the same year the Savannah launched, Popular Science ran a short feature designed to quell readers’ fears: “How Safe Is Our A-Ship Savannah?” The staff-written story read more like a safety brief than an objective review. While boasting about its efficiency—“on a single loading of A-fuel, the Savannah will have a range of 350,000 nautical miles”—the article focused mainly on the “worst possible accidents that might befall the first atomic merchant vessel.” Such caution seemed justified. That same year, Denmark canceled a scheduled visit by the USSSkate to Copenhagen, and England agreed to receive visiting nuclear submarines only at the remote Isle of Portland, population 12,000, rather than major ports.
Popular Science’s initial coverage was not anomalous. “Passengers will receive no more radiation on the Savannah than they receive from normal background radiation of the earth in their day-to-day lives,” The New York Times reassured its readers.
By 1961, however, as the Savannah prepared to begin its cargo and passenger service, which commenced in 1962, Popular Science’s editors were fully onboard, launching a four-part series that spanned four consecutive issues and more than a dozen pages. The do-it-yourself mini-manual provided detailed instructions for readers to build and sail their own four-foot model of the ship. Four different writers and editors took part in the project: hull casting one month, superstructure the next, then a working steam turbine, and finally radio controls. Even as Popular Science promoted its features, the real Savannah was being fitted with Heaney’s final touches.
The January 1961 issue of Popular Science shows a model of the NS Savannah assembled with screws and dowels. Image: Popular Science, January 1961 issue
Domesticating the atom
On a conventional ship, fuel is stored low in the hull, in tanks that any port can refill with diesel by hose. But Savannah’s single, massive fuel core had to sit in the hull’s center, beneath an opening in the deck, so it could be accessible by overhead crane for refueling. Heaney’s answer to this exterior design problem became the ship’s signature: a streamlined, teardrop-shaped superstructure. Popular Science’s writers praised Savannah’s sleek, futuristic lines as “graceful as a racing yacht’s,” and called its reactor housing “a well-placed superstructure [that] blends airfoil curves with sharply angled planes for a dazzling effect.”
Below decks, Heaney took the fear problem head on, weaving Atomic Age motifs into the ship’s interior. In the veranda, the cocktail bar’s backlit wine rack depicted the trilinear chart of the nuclides in blue, red, and yellow glass; the tables ringing the dance floor glowed, their tops lit by “panelescent,” or electrically charged luminescent panels. Even the floor tiles in the main stairwell carried the atomic theme. A separate lounge nearby offered passengers a closed-circuit television view into the reactor containment vessel. Overhead light beamed down through light fixtures adorned with stylized atoms.
In the dining room, sculptor Pierre Bourdelle installed a wall mural titled “Fission.” Nearby, suspended in glass, hung a small gold model of the NSSavannah’s namesake, the 1819 steamship SSSavannah, the first ship to cross the Atlantic under sail and steam. Heaney hoped such Old World symbolism would make people feel comfortable dining, dancing, and sleeping no more than a dozen yards from a nuclear reactor.
As a design achievement, Savannah was a triumph. Her passenger cabins were mostly full from 1962 to 1965, and more than 1.4 million people toured the ship across 46 ports in 13 countries.
Even the plates and silverware used on the NS Savannah had an atomic motif. Image: Baltimore Sun / Contributor / Getty Images / Kim Hairston
Sunk by economics—and fear
But novelty was never going to be enough to move public sentiment or make Savannah pay for itself. The combined ship-and-reactor construction cost ran to roughly $46 million, three to four times what a comparable conventional freighter cost at the time, and the ship’s specialized nuclear crew commanded specialized wages. No private insurer would touch a nuclear-powered merchant ship; the U.S. government had to indemnify it instead, extending $500 million in federal liability coverage just to get foreign ports to receive the ship. Every port call required a small diplomatic mission of its own, negotiated weeks in advance, with tugs standing by in case of an accident. Some countries, like Australia, New Zealand, and Japan, never accepted Savannah.
By the end of the 1960s, the U.S. Defense Department, one of merchant shipping’s largest customers, had concluded that conventional freighters remained the better bet. With no federal appetite left to continue funding a revenue-losing program, Savannah was withdrawn from service in late 1971 with no plans to build another.
The timing proved fateful. Two years after Savannah was decommissioned, the 1973 oil embargo sent fuel prices soaring; had it still been sailing, the ship’s independence from oil might have tipped the scales for commercial customers, even if the public remained fearful.
Fear kills future “A-ships”
In 1979, the partial meltdown at Three Mile Island—eight years after Savannah’s own retirement—hardened American public fear of nuclear power for more than a generation. The Soviet Union’s Chernobyl accident in 1986 and Japan’s Fukushima accident in 2011 reinforced that fear.
Three other nations tried what the U.S. attempted with Savannah, and each ran into the same wall. West Germany’s nuclear-powered merchant ship Otto Hahn logged 650,000 nautical miles over a decade before port restrictions and rising costs forced her conversion to diesel in 1979—the same year as Three Mile Island.
Japan’s nuclear-powered Mutsu fared worse. Local fishermen blockaded it in harbor for two years before the ship could even sail, and when its reactor went online in 1974, it leaked. The crew had to improvise radiation shielding using boiled rice and old socks.
The Soviet Union’s nuclear-powered Sevmorput, the last of the four and the only one to operate into the 21st century, has sat idle at a dock in Murmansk since 2024. As of today, not a single nuclear-powered merchant ship plows the seas anywhere on Earth.
And yet, military fleets have proven the technology works. The U.S. Navy alone has logged more than 6,200 accident-free reactor-years since 1955. What’s more, reactor designs have advanced significantly since Heaney’s day. Small modular reactors, or SMRs, have been engineered to be smaller, safer, and simpler to certify than anything available in 1959. SMRs are now in active development for maritime use, including a Norwegian consortium’s NuProShip program, and a molten-chloride test reactor that Core Power and TerraPower are building at the Idaho National Laboratory.
The pressure to act has intensified, too. Commercial shipping produces more than three percent of global greenhouse gas emissions—a share that could climb to 10 percent by 2050 if the industry does nothing while the rest of the world decarbonizes. In 2023, the International Maritime Organization, which governs commercial shipping, committed its member states to a net-zero target by 2050, a goal serious enough that the IMO is now weighing previously unthinkable measures like SMRs.
But none of it matters if nuclear-powered merchant ships remain taboo.
Sixty-five years after Jack Heaney tried to make the atom desirable, the real problem with nuclear reactors was less about the technology and more about public perception. Unfortunately, that perception has kept a viable climate solution off the table for more than half a century, at a cost now measurable in our planet’s atmosphere. As the shipping industry searches for a way to shed its considerable share of global carbon emissions, it is not physics but persuasion that remains unsolved.
In A Century in Motion, Popular Science revisits fascinating transportation stories from our archives, from hybrid cars to moving sidewalks, and explores how these inventions are re-emerging today in surprising ways.
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