Breakthroughs and trends in the world of technology
Heart of Darkness
The deep ocean is an unforgiving habitat, full of predators and short on hiding places. Some creatures, such as the fangtooth fish, have evolved a way to elude detection: skin so ultrablack that they’re nearly invisible in the inky depths. Marine biologists at the Smithsonian National Museum of Natural History recently figured out the secret to the camouflage, according to Science News. In a recent paper, the investigators explain that just below the fishes’ skin is a layer of melanosomes, or densely packed circular structures containing the pigment melanin, that absorb 99.95 percent of light. Normal dark-colored fish tend to have unpigmented gaps between their melanosomes that can reflect light and render them somewhat visible. By contrast, the size, shape, and arrangement of the melanosomes in ultrablack fish appear to redirect light that isn’t fully absorbed by an individual melanosome to others nearby, so hardly any is reflected. The Smithsonian team studied 18 species of superblack fish caught off the coast of California and in the Gulf of Mexico from up to 2,000 meters deep. The researchers measured how much light the skin of these stealthy swimmers reflected and used electron microscopy to investigate the structures within the skin of nine species. Their findings could help engineers develop superblack materials used, for example, to shield space telescopes from stray light or to hide submarines. – Thomas K. Grose
©Karen Osborn, Smithsonian
PFAS, or perfluoroalkyl and polyfluoroalkyl substances are a family of more than 4,000 compounds found in products ranging from food packaging to nonstick pans. Nearly impossible to destroy, they’re often called “forever chemicals” because they linger in the environment—and in the blood of virtually every American. Perfluorooctanoic acid (PFOA) is one of the toughest to eradicate. But in a surprise discovery, a team of Rice University chemical engineers found that one of the light-activated catalysts they’d been testing in benchtop experiments destroyed 99 percent of the toxic chemical in four hours. The researchers had been using boron nitride (BN) powder, a synthetic mineral found in many consumer and industrial products, including makeup and the thermal pastes used to cool computer chips, as a control chemical in otherwise unsuccessful trials to scrub PFOA-contaminated water. However, when they added BN and exposed the water to UV-C light with a wavelength of 254 nanometers, most of the PFOA was converted to fluoride, carbon dioxide, and hydrogen. The team isn’t entirely sure why that happens, since that UV wavelength—commonly used in germicidal lamps—is too small for BN to absorb. The researchers surmise that the BN they used has atomic defects that slightly altered its bandgap and allowed it to absorb light. Meanwhile, chemical and biomolecular engineers at the University of Sydney recently developed an industrial wastewater treatment process capable of cleaning up a cocktail of pollutants, including carbon, nitrogen, and phosphorus. Their technology uses electricity generated from specialized electrodes to drive oxidation reactions near the electrodes’ surfaces, turning the toxins into harmless gases, ions, and minerals. – T. G.
What happens when you blend kirigami, the ancient Japanese art of paper cutting, with twisting balloons into whimsical shapes at birthday parties? Engineers at Harvard University have paired the two and come up with an innovative way to mold inflatable devices into simple or complex pre-programmed shapes. First, they slice periodic cuts into kirigami sheets and then embed the paper inside a balloon. As the balloon inflates, the cuts in the paper guide its growth, allowing some areas to expand while constricting others. Each cut contributes to the balloon’s larger shape, similar to the way pixels form images on a two-dimensional screen. The researchers can tune the geometric parameters of the cuts using an inverse algorithm they developed, thus ensuring the balloon morphs into a target shape—which can range from bends to twists to expansions. In experiments, they’ve programmed balloons to mimic the shapes of squashes, hooks, and vases. The team hopes to use kirigami balloons as shape-shifting controllers for soft robots. But other future uses could be huge—such as structures for space exploration—or tiny—including minimally invasive medical micro-tools. – T. G.
©Bertoldi Lab/Harvard SEAS
Cosmic Birth Certificate
So now it’s confirmed: The universe is around 13.8 billion years old. That age was first suggested seven years ago by the international Planck mission that used satellites to measure ancient light. But other measurements indicated the universe was several million years younger. Recently, though, a team of scientists from 41 institutions in seven countries investigated an image of the oldest light in the universe and pegged the universe’s age at 13.8 billion years. As USA Today reports, the picture they studied was an image from Chile’s Atacama Cosmology Telescope (ACT) of “afterglow” light, which comes from a point some 380,000 years after the Big Bang, when protons and electrons fused to form the first atoms. One researcher likened it to a “baby photo” of the early universe that scientists restored to pristine condition, eliminating the wear and tear of time and space that had distorted it. Because the ACT and Planck studies agree, “it speaks to the fact that these difficult measurements are reliable,” another team member concluded. The confirmation of the universe’s age came several months after a research team at Durham University in England was finally able to measure the diameter of the Milky Way, Science News reports. Using computer simulations to look at the gravitational pull between our galaxy and others nearby to delineate its edges, the astrophysicists calculated that the Milky Way is 1.9 million light years across, give or take 0.4 million light years. – T. G.
As bee populations continue to decline worldwide, some farmers have resorted to pollinating crops with sprays or manually brushing pollen onto plants. But sprays waste a lot of pollen and hand-pollination, while effective, is labor-intensive. Eijiro Miyako, a materials chemist at the Japan Advanced Institute of Science and Technology, has become a leader in looking for new technologies to abet Mother Nature. Three years ago, as noted in First Look, he developed a robot bee that carried horsehairs covered in a gel he developed that could not just pick up pollen, but also release it on a pistil. Miyako is now working on autonomous drones that blow pollen-infused bubbles onto crops. He found that bubbles made of lauramidopropyl betaine, a chemical commonly found in cosmetics, kept pollen grains healthy and viable, Science News reports. His team blew pollen bubbles onto 50 blossoms on three pear trees, and 95 percent of them formed fruit—a success rate equal to hand-pollination. Next, Miyako had a drone blast pollen bubbles at fake lilies while it flew by at a pace of two meters per second. While bubbles hit more than 90 percent of the lilies, many more bubbles were wasted. To make the technology work, he says, drones will need to be able to recognize target flowers and aim their bubble guns more precisely. Some researchers applaud the clever engineering but contend machines will never be as effective as bees. They argue that while robotic solutions get media buzz, greater effort should be made to protect natural pollinators. – T. G.
Spider webs are strong, elastic, and harmless to human cells. Those physical, mechanical, and chemical properties have caused researchers to see them as promising biomaterials for a range of medical applications, including skin, bone, and cartilage regeneration along with wound dressings. Investigators at Taiwan’s National Yang-Ming University have come up with an unexpected new use for natural spider silk: biocompatible lenses for biological imaging applications, ScienceDaily reports. Spiders can spin several types of silk, each with a specific purpose. For the spokes of their webs, they spin a type called dragline silk—which, on a weight basis, is stronger than steel. In a recent paper, the team describes how they collected dragline silk from Pholcus phalangioides spiders—daddy long-legs to you and me—and dripped a resin on it. As the resin condensed, the silk’s wetting properties caused it to naturally form into a dome shape, which worked as an optical lens. When hit with a laser, the lens can generate a high-quality photonic nanojet, or beam, capable of providing large-area, high-resolution imaging for biomedical applications. By changing the time the silk spends under the drop of resin, the researchers are able to vary the size of the dome lens and optimize the photonic nanojets to accommodate different kinds of imaging. – T. G.
Feign the Whole Brain
Most brain-inspired artificial intelligence systems are based on the structure and functions of neurons, the cells that transmit nerve impulses and allow us to process and learn information. But our gray matter contains two to 10 times more of another type of cell: astrocytes. For decades, these star-shaped cells were largely ignored by computer scientists. But it’s now known that astrocytes are key to such things as memory and central-pattern generation—the brain activity that controls breathing, locomotion, and other rhythmic behaviors. A Rutgers University team led by Konstantinos Michmizos, an assistant professor of computer science, is developing brain-inspired algorithms that account for and replicate the function of astrocytes, Tech Xplore reports. In a recent paper, the researchers describe how they designed computational models that consider what happens inside an astrocyte as it communicates with neurons, then used the models to build neuron-astrocyte networks embedded in neuromorphic chips to control virtual robots. In a simulated environment, the chip controlled the walking of a six-legged robot, and the team expects to use the technology to control an actual robot soon. As Michmizos tells Tech Xplore, the impetus behind his lab’s work is “to understand the mysterious language that neurons and astrocytes use to talk to each other as we learn, think. and act on our world, by building algorithms inspired by this mysterious dialog in our brain.” – T. G.
License to Thrill?
Founded by engineer Colin Chapman in 1952, Lotus Cars built a reputation in the 1960s and ‘70s for elegant, high-performance vehicles. The iconic British automaker won global attention in 1977 when its Lotus Esprit S1 debuted as James Bond’s glamorous, submersible ride in The Spy Who Loved Me. Despite a successful automotive engineering consulting business, however, the company—now owned by Chinese firm Geely, which helped turn around Volvo—has struggled financially. To rev up revenue, Lotus is setting up shop at Britain’s University of Warwick and betting big on its future in electric vehicles. The initiative, in partnership with the Warwick Management Group, an academic research and industrial consulting unit within the engineering school, will include offices, labs, and workshops, and initially employ 130 engineers—complementing the 500-person engineering team at Lotus’s Norfolk headquarters. Lotus sports cars are renowned for being lightweight and responsive, but battery packs are heavy, so a research priority will be generating designs that shed weight, reduce drag, and increase battery range. WMG’s expertise includes battery engineering and vehicle propulsion systems, and its engineers have worked closely with another elite British automaker, Jaguar Land Rover. Electrifying cachet may take a while. Despite early reports, 007 isn’t swapping his V-8 for an all-electric Aston Martin in No Time to Die—due for release in November—though the film, 25th in the Bond franchise, features plenty of other classy chassis. – T. G.
Made in the Shade
Generating electricity from sunlight follows a simple formula: sunshine good, shadows bad. But National University of Singapore (NUS) researchers have invented a device that flips that order, Science News reports. Their shadow-effect energy generator exploits the voltage difference between shaded and illuminated silicon cells to produce an electric current. Like many solar cells, each generator is a slice of silicon. But these special shadow users include a super-thin coating of gold. When light strikes silicon, the excited electrons jump to the added gold, allowing the resulting current to be captured and used. The generator works only when partly illuminated—it loses power with full illumination or full shadow. The NUS team, led by assistant professor of materials science and engineering Swee Ching Tan, used eight of the cells to run an electronic watch in low light. The shadow generator also worked in a sensor that lit an LED from a shadow generated by a remote-controlled car. Possible future uses of the technology include cells that use indoor lighting to power personal electronic devices or additions to solar-cell arrays to produce extra power when they’re partially shaded. – T. G.
©Royal Society of Chemistry
The programming terms “master” and “slave” became commonplace in the years after the Second World War as a metaphor to describe the subordination of one electronic component or command to another. Ron Eglash, a University of Michigan professor who studies ethnomathematics, or the relationship between math and culture, tells the Boston Globe that it’s unclear if the usage was racially motivated, but notes that the language of engineering can be boring and those terms made the concept of control easy to grasp. Roscoe Giles, a Boston University computer engineering professor and the first African American to earn a Ph.D. in physics from Stanford University, always found the metaphor “distasteful” and instead substitutes “boss” and “worker” in his classes. This summer, with Black Lives Matter protests erupting nationwide, one of his graduate engineering students, Santiago Gomez, 28, came across the offensive terms in a textbook and was galvanized to get them abolished. He persuaded textbook publisher Pearson to drop the metaphor from more than 600 print and digital titles and replace it with either “leader and follower” or “first and second.” Similar efforts are underway in industry and professional societies. The IEEE, for example, is starting a process to review the language used in its standards, while software-developer platform Github is switching to more inclusive terminology. Gomez, whose letter to Pearson called master-and-slave terminology “an example of how systemic racism functions in America,” says the publisher’s move is an important step toward rectifying the problem, the Globe reports. But Eglash worries that these “cosmetic, tidying-up activities” give the tech industry an easy out, allowing it to sidestep deeper inequities, such as underrepresentation of women and African Americans or the focus on solutions that benefit corporations rather than communities. – T. G.
Last year, British heavy-equipment manufacturer JCB introduced the world’s first fully electric digger. This summer, the 19C-1E won one of the U.K.’s most prestigious engineering innovation prizes, the MacRobert Award—a competition run annually since 1969 by the Royal Academy of Engineering. The award comes with a £50,000 ($65,500) cash prize and a gold medal. JCB’s battery-powered digger won over Jaguar Land Rover’s all-electric I-PACE SUV and a liquid natural gas reliquification technology developed by Scotland’s Babcock LGE Ltd. To date, JCB says the burgeoning fleet of 19C-1Es has saved the equivalent of 15,100 kilograms of carbon dioxide emissions across 5,616 hours of work. The company estimates that billions of tons of CO₂ emissions could be saved if its digger were used across the global construction sector. The 19C-1E also is much quieter than the diesel version, with cabin noise reduced by 10 decibels. Its four-battery pack can be charged overnight using standard industrial sockets, but JCB also offers a fast-charging option that can fully replenish the batteries in 2.5 hours from a 415-volt supply. The award-winning digger is already proving popular. The Pentagon recently placed a £217 million ($284.3 million) order, the Engineer reports. And dig this: The MacRobert is not the 19C-1E’s first prize. Last October, it won the Dewar Trophy for outstanding British technical achievement in the automotive industry from the Royal Automobile Club. – T. G.
Tough and elastic, cartilage is a wonder material that cushions the ends of bones, allowing joints to glide smoothly. The cartilage in our knees easily absorbs two to three times our body weight with each step. It can, however, wear out or suffer irreversible damage. As a result, some 600,000 knee-implant surgeries are performed in the United States annually. Artificial knees tend to last for only 20 years, however, so researchers have looked at hydrogels as a joint replacement. The water-based gels are slippery, can absorb shocks, and don’t harm cells. But until now, none has proved strong enough for use in knees. Recently, a team of engineers and chemists at Duke University has developed a hydrogel that shows promise. Essentially a distant cousin to Jell-O, the hydrogel is extremely strong: A quarter-size disk can bear the weight of a 100-pound kettlebell without tearing or losing its shape, and it also can withstand constant tugging without wearing out. Within the gel are two intertwined polymer networks: one consisting of stretchy, spaghetti-like strands, the other rigid and woven like a basket. Reinforcing the networks is a meshwork of cellulose fibers. When the gel is stretched, the fibers hold the material together. Squeeze it, and negative charges along the polymer networks repel each other and stick to water, forcing the gel to spring back to its original shape. Tests on lab-grown cells indicate that the material is nontoxic. The researchers are now developing an implant to test in sheep. – T. G.
Back in August, when SpaceX’s Crew Dragon space capsule successfully made the supersonic flight from the International Space Station to Earth, the two NASA astronauts on board were carrying a particularly symbolic bit of paraphernalia: a small American flag. The flag was aboard the first ever Space Shuttle flight in 1981 and has been housed on the ISS since November 2000, when it welcomed the first humans. After the space shuttle Columbia disintegrated upon reentry in February 2003, the Bush administration slowly pulled the plug on the shuttle program, and the last shuttle flew in 2011. Since then, the United States has relied on Russian spacecraft to ferry astronauts to and from the ISS. But 2011 was also the year that the Obama White House launched a competition to get NASA out of the spacecraft-building business and instead fund corporate partners. The president called the initiative a “capture-the-flag moment … for commercial spaceflight” because the winning company would be allowed to bring the flag back to Earth, Business Insider reports. The competition eventually narrowed to two rivals: SpaceX and Boeing. While Boeing had an early lead, software glitches caused it to stumble. In May, SpaceX’s Falcon 9 rocket launched the Crew Dragon ship into space. After safely splashing down two months later off the coast of Pensacola, Fla., astronauts Bob Behnken and Doug Hurley diplomatically stressed that the flag was a symbol of returning human spaceflight capability to the United States and not the triumph of SpaceX over Boeing. – T. G.