Breakthroughs and trends in the world of technology
Swiss engineers have constructed a tiny, ultralight robotic bug with superpowers. The DEAnsect can run a sprightly 3 centimeters per second on all types of terrain. It also bounces back from being folded, stepped on, or squashed with a flyswatter. Moreover, reports ScienceDaily, École Polytechnique Fédérale de Lausanne’s robot is smart. With a microcontroller for a brain and photodiode eyes, it can recognize black and white patterns and follow lines drawn on the ground. DEAnsect’s soft, artificial muscles are membranes made from hair-thin dielectric elastomer actuators (DEAs, hence the name), which propel the device by vibrations. The DEAs, which are fitted to the bug’s three legs, are sandwiched between two soft electrodes. When a small voltage is applied, the electrodes attract and compress the membranes; switch off the power and the membranes relax to their initial shape. The voltage is switched on and off more than 400 times per second to generate locomotion. The DEAnsect—which weighs a mere 0.2 gram—is tethered to very thin wires for power. Possible uses include using swarms to conduct inspections and remote repairs or spying on an insect colony to give researchers a better understanding of its behavior. Meanwhile, the Lausanne team is working with colleagues at Stanford University on a wireless, entirely soft version. Longer term, the researchers plan to outfit the robo-bugs with sensors and emitters so they can communicate with each other. – Thomas K. Grose
Are the eyes a window on hidden health woes? A research project underway in London aims to find out. AlzEye, a collaboration between Moorfields Eye Hospital and University College London, will use machine-learning algorithms to crunch through a database of retinal imaging performed on 300,000 Moorfields patients between 2008 and 2018 to see if it can detect subtle changes in the health of the retina that are linked to Alzheimer’s disease, The Economist reports. Some 15,100 patients in that large sample have been diagnosed with dementia. While there’s circumstantial evidence that Alzheimer’s affects the back of the eye, the article says, there’s no guarantee that even artificial intelligence can spot those changes. Even if the technique doesn’t work for Alzheimer’s, however, it may still turn up early indications for heart disease and strokes. If so, this could be a remarkably inexpensive game-changer, since retinal imaging is routinely done by retail opticians for just a few bucks. Early diagnosis could open the door to preventative treatment, further reducing health care costs. – T. G.
©Pearse Keane, Siegfried Wagner, and Dr Hagar Khalid
While battery performance has surged in recent years, a team at Australia’s Monash University says it has found a way to make a lithium-sulfur battery that would outperform all other power-storage devices currently on the market. Indeed, the researchers believe their battery could power a smartphone for five days or propel an electric car more than 620 miles—all on one charge. Lithium-sulfur batteries, which have been around since the early ‘60s, could have less environmental impact than the lithium-ion versions that dominate today. However,they are unstable and have a short cycle life. The team of mechanical and aerospace engineers at Monash says it has solved that problem by changing the manufacturing process to rearrange the sulfur cathodes so they can accommodate higher stress loads without losing capacity or performance. The method, which was inspired by a way of processing detergent powders in the 1970s, creates bonds between particles, enabling them to achieve stability. Beyond being four times more efficient than any other battery, the Monash model is also cheaper to produce, relies on widely available materials, and produces less environmental waste because it’s a water-based process. The team is now set to begin more tests on cars and solar grids in Australia and is working to commercialize the battery. Prototype cells have already been fabricated in Germany, and European and Chinese battery manufacturers are expressing interest. – T. G.
Lowering the Boom
Commercial supersonic transport came to a halt in 2003 when British Airways and Air France retired the Concorde after 27 years of service. The SST was always a money-loser, largely because its ear-shattering sonic boom mandated flying at subsonic speeds over land, which greatly limited its routes and commercial viability. But NASA has been working with Lockheed Martin for several years on a $250 million project to develop a new, quiet supersonic plane. Last month, the space agency approved the final assembly of the large-scale, piloted X-59 Quiet Supersonic Technology jet, putting it on track for a first test flight next year. The X-59 uses a radical type of aeronautic design that reduces the sound of the shockwave to “that of a gentle thump, if it’s heard at all,” NASA says. When it finally flies, the aircraft will soar over select communities to generate data from sensors and people on the ground, which will be used by regulators to set new rules for overland supersonic travel. The X-59 will have a cruising speed of Mach 1.42, or 1,090 m.p.h. That’s a tad slower than the Concorde’s speed of Mach 2, or 1,350 m.p.h., but who’s complaining? – T. G.
Sea stars (marine scientists’ preferred name for starfish) may lack a brain and centralized nervous system, but they manage to bounce along the ocean floor thanks to a complex communication network linking hundreds of tiny tube feet that stretch and contract under each of its five legs, according to researchers at the University of Southern California. When a sea star crawls, its tube feet move in the same direction but aren’t coordinated. When it “runs,” however, the tube feet synchronize to produce a bouncing movement. The USC team found that when the sea star’s “dominant arm” decides to move in one direction, each of its hundreds of tube feet figure out how to follow that directive on their own. How? The best analogy is a set of mechanical metronomes set at different phases; over time, through mechanical interaction, their rhythms will synchronize. Similarly, when a tube foot starts to move, it produces an individual force that becomes part of the sensory environment, cueing other feet to respond. Eventually, they establish a rhythm. “If one tube foot pushes against the ground, the others will feel the force,” explains Eva Kanso, the professor of aerospace and mechanical engineering who led the study. “This mechanical coupling is the only way in which one tube foot shares information with another.” Understanding how a sea star’s distributed nervous system can achieve complicated, coordinated movements, Kanso says, may help researchers program robots to navigate complex environments. – T. G.
Selecting a major is a big decision that can influence a student’s happiness in college, career path, and future earnings. But for some undergraduates, the choice may hinge on their introductory course schedule. That’s the upshot of a study led by Kareem Haggag, an assistant professor of humanities and social sciences at Carnegie Mellon University, that looked at the effects of fatigue caused by early-morning and back-to-back classes, Futurity.org reports. Haggag’s team analyzed the academic records of 18,000 U.S. Military Academy students from 2001 to 2017. West Point offers 38 majors in science, engineering, social science, and humanities, and freshmen are randomly assigned four core courses. Focusing on 14 classes considered to be first steps to a major, the researchers found that 10 percent of students assigned a core course early in the morning (7:30 a.m.) were less likely to opt for that course’s corresponding major. Those assigned a back-to-back course, with no scheduled break in between it and another course, were 12 percent less likely to select its corresponding major. Haggag says he can’t verify that fatigue was the cause for each student’s selection, but it seems the most likely reason, given the random mix of students in afternoon classes. He now plans to see if he can uncover similar findings at other colleges. – T. G.
Deepfakes are computer-generated videos and photos that transpose a person’s face onto someone else’s using artificial intelligence technologies. So far, 96 percent of these doctored images have been pornographic clips. But as the 2020 election year winds up, politicians will likely become targets of digital mudslinging. Moreover, as IEEE Spectrum reports, apps and services are popping up that make it easier to create deepfakes—prompting social-media sites and even DARPA to look for ways to identify and remove bogus images. In December, Facebook launched a global competition called the Deepfake Detection Challenge in cooperation with Amazon, Microsoft, the nonprofit Partnership on AI, and academics from eight universities. The goal of the contest, which ends in March, is to create automated tools that can spot deepfakes. Facebook will bestow more than $10 million in awards and grants to winners. Although the first deepfake videos didn’t surface until 2017 on Reddit, DARPA already had launched a Media Forensics program a year earlier to develop detection technologies. And in March, IEEE Spectrum says, DARPA is starting a broader follow-on program called Semantic Forensics that will cover all types of media: text, images, video, and audio. – T. G.
Researchers have long sought to create self-repairing concrete by adding bacteria or fungi to the traditional mix of sand, water, and binders. A multidisciplinary team at the University of Colorado–Boulder, led by Wil Srubar, an assistant professor of materials science and engineering, seeks to improve on that recipe by incorporating a type of cyanobacteria, an algae-like aquatic microbe. The result is a new type of living building material that can not only reproduce itself but also absorb, rather than emit, greenhouse gases. Moreover, unlike most concrete, which uses a special type of sand that’s becoming scarcer, this material can use any type of sand, even ground glass or recycled concrete. And the concrete is literally green—at least until it fully dries. The DARPA-funded research is part of the Defense Department’s quest for building materials that can be produced in remote areas. “Out in the desert, you don’t want to have to truck in lots of materials,” Srubar tells the New York Times. Normal concrete production emits large amounts of carbon dioxide, but cyanobacteria are energized via photosynthesis, which draws CO₂ from the atmosphere and generates calcium carbonate, a main ingredient in cement. Initially, the mix of sand, water, microbes, and nutrients, when warmed to 30º C, was slow to harden. But by adding gelatin to the mix, the process sped up while producing a “gummy scaffold” that strengthened the bonds forged by the cyanobacteria, Scientific American reports. Though less hard than conventional concrete, shoebox-size blocks of the material are strong enough for building construction. Srubar’s team is currently working to make its Franken-crete more robust. – T. G.
©College of Engineering and Applied Science, University of Colorado Boulder
Open-access journals have become popular because their research articles are free to the public, unlike traditional peer-reviewed publications. However, they charge authors to publish. In recent years, there’s also been a surge in so-called “predatory journals” that charge authors to publish but have little or no peer review or quality control. Some are fake versions of reputable publications, as Prism detailed in February 2017. A new study at the Hanken School of Economics in Finland finds that six of every 10 articles published in predatory journals attracted not one single citation over a five-year period, Science reports. The 40 percent that were cited had a much lower rate of citation than papers published by reputable journals. There have been concerns that false, low-quality, or misleading papers published by predatory journals would get too much attention and pollute the body of scientific work with erroneous or mediocre findings. But the Hanken researchers say their study shows the bogus journals are doing little harm. Still, Rick Anderson, an associate dean at the University of Utah, tells Science that if 40 percent of these articles are drawing at least one citation, it “strikes me as pretty alarming.” – T. G.
Collider On a Chip
Particle accelerators typically are massive, like the SLAC National Accelerator Laboratory at Stanford University, which is almost two miles long. They use bursts of microwave radiation to propel a stream of electrons through a vacuum pipe to nearly the speed of light and then train the beam on inorganic and biological materials to investigate their atomic and molecular structures. But as ScienceDaily reports, Stanford electrical engineers have built a silicon chip version of a particle accelerator. The researchers etched a nanoscale channel in silicon, sealed it in a vacuum, and sped electrons through it using pulses of infrared laser light. While the particles don’t reach the same speeds as those racing through the giant-sized models, a miniaturized accelerator could still be a valuable research or medical tool. For example, it may one day be possible to use a chip accelerator for cancer radiation therapy, sending an electron beam directly into a tumor and leaving the surrounding healthy tissue unscathed. To be effective, however, the mini-accelerator electrons must be ramped up to 94 percent of the speed of light, or 1 million electron volts. The initial version has just a single stage of acceleration, and the electrons will need to pass through around 1,000 more stages to reach that speed. Still, the researchers say that’s not a difficult hurdle and expect to have an inch-size chip accelerator by the end of the year. Quick work, indeed. – T. G.
A windowless building might be inhospitable and bleak, but it would keep 30 percent of the energy needed to heat and cool it from seeping through the windows. Nicholas Fang, an MIT mechanical engineering professor, has a better solution. He’s developed a smart film that can be affixed to window glass and remains transparent when the surface temperature is under 90º F. Once the temperature soars, it becomes milky and can block up to 70 percent of the incoming solar radiation, reducing cooling needs by 30 percent. And MIT grad student Elise Strobach has invented a high-clarity silica aerogel—which is 95 percent air as well as some silica nanoparticles—that, when sprayed between panes of glass, offers 50 percent more insulation than traditional windows. Meanwhile, South Korean researchers have devised a way to replace window glass with solar cells, The Economist reports. Powering office buildings with photovoltaic cells is difficult because so many are needed and space is limited. Today’s commercial cells, which are made from a silicon wafer, are so opaque, they’re nearly black. But the Korean researchers found a way to etch the silicon with tiny holes—each 90 to 100 microns across—so that it is as transparent as tinted glass but can still produce an electric current. The prototype has an efficiency of 12.2 percent as compared to 20 percent for today’s high-end cells and lets in far less light than tinted glass, but the researchers think their photovoltaic pane can be improved enough to make it commercially viable. – T. G.
©Xinhao Li and Chang Liu, at MIT MechE
The chiton is a marine mollusk with eight articulated shell plates that shields its soft body while also permitting movement—including curling into a ball. The combination of protection and flexibility attracted the attention of Ling Li, a Virginia Tech assistant professor of mechanical engineering, who aims to design better body armor for soldiers, according to ScienceDaily. To better understand how the scale armor works, the multi-university team led by Li first had to analyze the tiny scales of the girdle that encircles the chiton’s plates, including their internal microstructure, chemical composition, nano-mechanical properties, and three-dimensional geometry. The researchers next produced physical prototypes of a chiton-inspired scale armor using multi-material 3-D printers, then subjected them to direct mechanical testing using controlled loading conditions. When hit by a force, the scales converge inward and overlap to form a solid barrier. When not under force, they can move to provide varying degrees of flexibility. Smaller scales, like those that girdle the chiton, work best for areas that need maximum flexibility, while larger scales are more useful in areas that need the most protection. Li’s team will now try to design armor tailored to different body locations: larger, tougher scales for protecting chests, and smaller, more flexible scales for elbows and knees. – T. G.
©Ling Li at Virginia Tech
Antarctica’s normal weather conditions include temperatures that plummet below -60º Fahrenheit and winds of approximately 100 mph. Accordingly, the research stations that many nations established there in the mid-20th century were very basic and not necessarily built to last, the New York Times reports. For instance, Britain’s Halley Research Station was abandoned in 1968 after just 12 years. Four replacement stations—Halley II through Halley V—also had short lifespans. So in 2005, the British Antarctic Survey decided to take a novel approach for Halley VI and sponsor a contest among architects to design a structure that was not only more durable but more comfortable and energy efficient, as well. The winning design, by Broughton Architects, features a caravan-like string of modular units that should last 20 years. Each module sits atop four hydraulic stilts outfitted with skis, allowing the structures to rise above accumulating snow drifts or move elsewhere on the drifting Brunt Ice Shelf they call home. Several other countries are also constructing state-of-the-art stations. Spain has hired Broughton to design its new facility, with modular buildings clad in fiber-reinforced red plastic panels. Germany’s bof architekten designed a research station for India that incorporates the shipping containers used to deliver the building materials. America’s largest station, McMurdo, dates to 1956 and has grown ad hoc into a sprawling, energy-inefficient maze, the Times writes. So in 2012, the National Science Foundation hired OZ Architecture of Denver to develop a preliminary design that includes such “creature comforts” as gyms and lounges. – T. G.
©Hugh Broughton Architects