Breakthroughs and trends in the world of technology.
Structural Engineering
Hidden Weakness
It towered for centuries over Teotihuacán, the largest city in pre-Columbian Mesoamerica. Today, Mexico’s famed Pyramid of the Sun risks slowly sinking and crumbling like a sand castle. So warns nuclear physicist Arturo Menchaca, who led a recent National Autonomous University of Mexico study that revealed a giant pile of dry dirt on the structure’s southern side, equivalent to roughly 10 percent of its total volume. That’s significant given that the exterior’s 3 million tons of volcanic rock rest on a mound of earth. Menchaca, who discovered the unstable spot while using a sub-atomic particle detector to search for internal chambers, attributed the soil’s 20 percent lower density to sun exposure. (The pyramid, built around A.D. 100, was excavated in 1910.) Wetting the dry side, one proposed solution, could only exacerbate a problem with excess moisture, however. Cement additions, to shore up the pyramid’s rock-and-earth exterior decades ago, hindered vegetation growth, but they also prevented dampness from escaping, causing cracks. UNESCO cited such restoration efforts – along with land-use pressures – as a threat to this World Heritage site. While researchers consider ways to prevent the pyramid’s damage or collapse, the cement is being replaced with river sand and other more sustainable materials. – Mary Lord
Computer Science
Big Brain Theory
Watson, the IBM cloud computing system best known for its 2011 victory on the TV quiz show Jeopardy! is now trying to find treatments for patients with glioblastoma. The aggressive form of brain cancer kills more than 13,000 Americans a year, usually a year after diagnosis. Watson, whose specialty is plowing through vast amounts of data rapidly, will work with doctors at the New York Genome Center in a trial initially focused on 20 patients. After physicians sequence the patients’ DNA, Watson will combine that information with data from mutation databases and relevant medical literature to search for the best treatments for each individual. Watson also is involved in a similar cancer-research effort at Memorial Sloan-Kettering Cancer Center in New York that began in 2012. Using supercomputers to help physicians develop lifesaving therapies is part of IBM’s effort to pivot from hardware toward cloud-based software services. Watson’s data-reading prowess is well-suited to research in several industries, including finance and customer service. Accordingly, IBM recently announced a $1 billion investment to give Watson a separate business division headquartered in New York. – Thomas K. Grose
© IBM
Biomedical Engineering
Virtual Painkiller
It’s not unusual for the brains of some amputees to register pains coming from their severed extremities. Sweden’s Ture Johanson, for instance, has suffered from phantom limb pain (PLP) since losing the lower part of his right arm in a car accident 48 years ago. The 73-year-old tried all the usual therapies, but none worked. Then he became the initial patient to try a radical new augmented-reality treatment developed by Max Ortiz Catalan, a doctoral student in biomedical engineering at Sweden’s Chalmers University of Technology. Johanson’s stump was wired to a computer that picked up the electrical signals sent from his muscles, which allowed him to move a computer image of an arm and hand. The technique helped reduce his pain and shorten the time he feels it from minutes to seconds. Catalan says allowing Johanson to use his muscles and see the results may trick his brain into thinking its motor commands are being carried out and that “the amputated arm [is] back in place.” Next up is a clinical trial that targets long-term PLP sufferers like Johanson. If it also works, virtual relief may soon be a reality. – TG
© Ortiz Catalan et al
Orthopedics
By a Thread
Silk has many uses, from neckties to sheets for the top 1 percent. But researchers at Tufts University and Boston’s Beth Israel Deaconess Medical Center recently came up with a truly novel use: silk screws and plates used to mend broken bones. Typically, “fixation devices” to repair broken bones are made of metal alloys. But metal implants can cause infections or corrode. So a second round of surgery often is necessary to remove them once the bone heals. Resorbable devices made from polymers can cause inflammatory reactions, and they’re so soft that surgeons first must drill holes in the bone and etch them with threading to hold the screws in place. Not so for silk screws. Silk thread is as strong as steel and is safely absorbed by the body. To make the devices, the Boston team dissolved silk proteins harvested from silkworm cocoons in alcohol, then poured the solution into molds and baked it. In a test using 28 screws implanted in six lab rats, none failed and all maintained their mechanical integrity. Coming next: clinical trials. – TG
© Thinkstock
Wind Power
Holy Bat, Batman
Many remote and island communities rely on diesel generators for power. Such generators also supply electricity in disaster areas. A cleaner alternative may be the buoyant airborne turbine, or BAT, developed by Altaeros Energies of Boston, an MIT spinoff. Housed inside a fabric shell filled with helium, the wind turbine can float to altitudes of 1,000 to 2,000 feet, where winds are stronger and more consistent. Its three tethers also double as cables to send power to a portable ground station. BAT is designed to handle winds up to 100 mph in all kinds of weather. Last year, a prototype successfully handled 45 mph winds while 500 feet aloft. Altaeros, which is targeting the $17 billion global remote-power and microgrid market, claims BAT can produce power for around 18 cents per kilowatt-hour. For many far-flung communities, that’s a bargain rate. Another benefit: BAT also can supply WiFi connectivity, another scarce resource. – TG
© www.valentinangerer.com
Stealth Technology
Invisibility Cloak
Paging Harry Potter. Engineers at Duke University have invented a cloaking device that tricks sound waves into acting as if there’s nothing beneath it. The team led by Steve Cummer, an electrical and computer engineering professor, used mathematical design tools to create a structure of plastic plates separated by exact distances and set at specific angles. Their device intercepts sound waves and redirects them around the cloak to the other side with the same phase and time delay they would have had if nothing had been there. The cloak eventually might hide ships from sonar or improve acoustics in auditoriums and other buildings. Meanwhile, the effort to develop an invisibility cloak got a new boost from researchers at the National University of Singapore (NUS). Building on U.K. efforts begun nearly a decade ago that focused on manipulating light waves, the Singapore team used “bulk natural materials” to hide thermal signatures – and thus render an object or person invisible. In 2012, French researchers had proposed using man-made metamaterials to cloak heat sources, but the NUS team said such materials would require a complex design to imbue them with special properties. – TG
© Duke University
Nanotechnology
Spray-On Solar Panels
Silicon-based materials remain the gold standard for making solar cells, but production requires heating to temperatures of around 1,500 degrees Centigrade. The brittle elements also require rigid frames, often of aluminum or glass, making units quite heavy. That translates into high delivery and installation costs – typically more than half a solar pane’s total price. A team at the University of Alberta in Canada is working on a cheaper, lighter material made from nanoparticles of zinc and phosphorus, which are both abundant and nontoxic. Dissolved in an ink, the cells can be sprayed in thin layers on a plastic substrate. Team member Erik Luber, a postdoc in materials engineering, says these flexible panels could then be unrolled on rooftops and “could even be used in window blinds, clothing, or on backpacks.” He says that zinc phosphide solar cells are particularly suitable for the roughly half of the world’s regions that currently are off the grid, including the Arctic, “where some communities are flying in diesel [fuel] by helicopter to supply their energy needs. These solar panels could provide a much cheaper energy alternative.” – Pierre Home-Douglas
© Thinkstock
Robotics
Wit’s End
In the man vs. machine smackdown, humans are still ahead but robots are gaining quickly. In Japan, an effort begun in 2011 to program an automaton that could ace the University of Tokyo’s tough entrance exam is starting to bear some fruit. The robot took a mock version of the test last year but fell a few points short of the goal of scoring 50 percent. Still, programmers at Japan’s National Institute of Informatics say the brainy bot has an 80 percent-plus probability of passing the entrance exams of 404 other Japanese universities. With two more years before the project concludes, time seems on the robot’s side. Meanwhile, a top table tennis player faced off against “the fastest robot on Earth,” a robotic arm made by German robotics company KUKA. Filmed in Bulgaria for a KUKA commercial, the match pitted a 114-pound, six-axis Agilus arm against former world champion Timo Boll, currently No. 5. The robot quickly racked up a 6-0 lead, but Boll ultimately prevailed 11-9 by strategically placing impossible-to-return shots. – TG
© KUKA /YouTube
Alternative Energy
Green Light
Harvest electricity? That’s the promise of biophotovoltaic energy, which essentially exploits photosynthesis – the process by which plants convert sunlight into chemical energy – to create electricity. Engineers and chemists at Britain’s Cambridge and Bath universities recently used moss and algae to power a digital clock and a radio. They also unveiled a prototype moss table, which would use BPV to power a built-in lamp. Here’s how BPV works: Photosynthesis releases certain organic compounds into the soil, where they’re broken down by bacteria. A by-product of those efforts is electrons, which can be harvested using connective fibers in the dirt. The moss table’s top is covered with 112 small moss pots, which together can generate about 0.4 to 0.6 volts. Though tiny, it’s enough to run the clock. Meanwhile, researchers at the Valldaura campus of the Institute for Advanced Architecture of Catalonia in Spain built and installed a BPV panel they say could also power small devices. Who knows? Someday we may grow all the electricity we need. – TG
© Thinkstock
Battlefield Medicine
Healing Jab
A leading cause of death for U.S. soldiers is “bleeding out,” or hemorrhaging from a bullet wound that can’t be treated with a tourniquet or external manual pressure. But a potentially lifesaving solution is now available from Oregon-based RevMedx. It’s essentially a large syringe filled with wood-fiber sponges compressed to a quarter of their size and treated with a coagulant derived from shrimp shells. A medic uses the XStat to inject the sponges into the wound, and the bleeding stops within 15 seconds. RevMedx’s engineers got the idea from expanding foams used to plug tire holes. The sponges also contain a marker that’s detectable by X-ray, which should ensure that none is accidentally left in a victim’s body. RevMedx developed XStat on a $5 million U.S. Army contract, but it likely will find a non-military, domestic market for the $100 device, given the more than 100,000 Americans wounded by guns each year. – TG
© Thinkstock/ RevMedx
Autonomous Vehicles
New Horizons
Drones are literally becoming a high-flying technology. Google just beat out Facebook to acquire Albuquerque-based Titan Aerospace, a maker of high-altitude drones, for a reported $60 million. Titan’s solar-powered atmosats, or atmospheric satellites, soar to around 12 miles – well above air traffic in the lower part of the stratosphere – and can stay aloft for five years. Google sees the technology as a way to provide wireless Internet coverage to mobile devices in areas not now served. Meanwhile in France, a group of defense contractors led by Thales Alenia Space say they are developing a StratoBus that’s “halfway between a drone and a satellite.” The football field-size blimp would hover in a geosynchronous orbit some 13 miles above the ground using solar-powered electric motors. A fuel cell would store energy. Thales says the helium-filled dirigible could be used for surveillance, telecommunications, and broadcasting during its five-year span. Several American and U.K. companies over the past decade have floated the idea of using stratospheric blimps to improve cellular coverage, but so far none has taken off. – TG
© Thales Alenia Space