Breakthroughs and trends in the world of technology.
Tissue Engineering
Spinning Sensation
Back when he was a graduate student doing research on electrospinning, the process for creating nanofibers with electric fields, Leon Bellan attended a lecture on tissue engineering and learned there was a big need for a better way to create artificial vascular systems in engineered tissue. Bellan, now an assistant professor of mechanical engineering at Vanderbilt University, realized that electrospun fibers might be a solution. He also recalled that they are often described as looking like cotton candy. So he bought a $40 cotton-candy machine and began tinkering. As it turns out, cotton candy fibers are a tenth of the diameter of a human hair, which is about the size of capillaries, the tiny blood vessels that bring oxygen and nutrients to cells and carry away waste. Bellan used the cotton candy-making technique to produce a 3-D artificial capillary system that keeps cells alive, viable, and functional for a week. The nano-size fiber networks Bellan’s process creates work as a template for artificial capillaries to form in engineered tissue. One big hurdle Bellan had to overcome is that the temporary structures need to be insoluble in the water-based gels used to create tissue scaffolds, but must later dissolve to create the microchannels. He ended up using a polymer called Poly(N-isopropylacrylamide), which is insoluble in temperatures above 32 degrees Celsius but soluble when the temperature cools. – Thomas K. Grose
©Bellan Lab/Vanderbilt University/Thinkstock
Biomimicry
Awesome Critters
As anyone who has ever tried knows, killing a cockroach isn’t easy. Fast and seemingly impervious to being stomped, the insects can disappear into the tiniest of cracks. To find out what gives the critters such superpowers and whether they can be replicated in robots, engineers at the University of California–Berkeley filmed a bunch of roaches through an obstacle course. They found that cockroaches can compress their bodies to a quarter of their height, allowing them to squeeze through a crevice as small as two stacked pennies. They can withstand pressure of 900 times their body weight—for an average-size human, that would be 123,000 pounds. And once they are flattened, their splayed legs can still function and zip them along at a speed of 20 body lengths per second. How do they manage all that? The roach exoskeleton is hard, but its rigid plates are connected to very flexible tissue. When they are squished, their splayed legs can still get enough grip to move them forward quickly in a unique type of locomotion. Using this information, the team devised CRAM, or compressible robot with articulated mechanisms. The palm-size, shelled, and six-legged ’bot can keep moving even when compressed in half, and can handle pressure up to 20 times its body weight. Roach-like robots such as CRAM may one day be used to search for survivors or gather intel amid building debris caused by natural or manmade disasters. – T.G.
©Tom Libby, Kaushik Jayaram, and Pauline Jennings/PolyPEDAL Lab, UC Berkeley
Nanoscience
Sperm Accelerator
For a man to impregnate a woman, a healthy sperm count often isn’t enough. His sperm must also be good swimmers. Low-motility sperm are sluggish and sometimes just swim in circles instead of zeroing in on the egg. To perk up their sperm, infertility clinics advise men to make lifestyle changes—things like losing weight, quitting smoking, or avoiding heated car seats. Now researchers at Germany’s Integrative Nanosciences at IFW Dresden have created a possible new therapy: nano-size spermbots. They’re actually metal helix structures that attach themselves to the tails of sperm and are powered by a rotating magnetic field that drives the sperm forward. Once a sperm hits the egg’s wall, the helix spins in the opposite direction to release itself. The spermbots might allow more couples to use artificial insemination rather than in-vitro fertilization, which is a more complex and expensive procedure. But, as Science magazine notes, the spermbots still need a sophisticated tracking and guidance system. And there is also another tiny hurdle: Sometimes the helixes get stuck and won’t release the sperm. – T.G.
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Careers
Doing Good, Doing Well
For a growing number of engineering students engaged in humanitarian projects or service learning, the question upon graduation is: What now? Khanjan Mehta, assistant professor of engineering design at Penn State, offers an answer—or series of answers—in Solving Problems That Matter (And Getting Paid for It), a collection of essays and profiles of engineers and other STEM professionals who became social entrepreneurs. They include Sara Farley, Stanford-trained World Bank consultant and founder of the Global Knowledge Initiative, which aims to expand science and technology in the developing world; Michigan Tech mechanical engineer John Gershenson, seller of high-quality parts to sub-Saharan Africans dependent on bicycles to earn a living; and Nathan Johnson of Arizona State’s Polytechnic School, who pioneered a better, safer cookstove for poor nations. Engineers, writes Rob Goodier of Engineering for Change (E4C), bring to the table a powerful ability to build something useful. Another lesson from the book: Listen both to your inner Mother Teresa and your inner Ray Kroc—don’t be afraid to make money. – T.G.
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Data Centers
Deep Chill
The “cloud” sounds light and airy. But it’s actually composed of many data centers—huge warehouse-size buildings crammed with servers—that generate an awful lot of heat. Keeping them cool requires a costly amount of air conditioning. So some companies are stationing data centers in cool climes. Facebook has, for instance, a center in northern Sweden. But Microsoft is trying another approach—sinking them into the chilling waters of Davy Jones’s locker. Its Project Natick envisions submerged data centers just offshore. As Microsoft notes, half the world’s population lives within 120 miles of a coast, so moving more data centers closer to consumers would speed data transmissions. Additionally, a data center on land can take up to two years to build, but Microsoft says mass-produced steel capsules that house many racks of servers could be manufactured within 90 days. Eventually they might be powered by renewable underwater turbines or tidal power. Toward that goal, in a first test of the idea, Microsoft last August lowered an eight-foot-wide, 38,000-pound steel capsule filled with servers into 30 feet of water a little more than a half mile off the California coast, and kept it running for 105 days. The capsule was covered with around 100 sensors to measure things like pressure, humidity, and motion. Microsoft engineers say it performed beautifully. But hurdles remain. The ocean is a harsh environment. Heavy seas and salt water can take their toll on equipment over a long haul. And Microsoft needs to design servers that can run for five years with no human maintenance. So it’s not yet entirely clear whether submerged data centers are the next big wave. – T.G.
©Microsoft
Satellite Propulsion
Running in Space
CubeSats, miniature satellites around 4 inches on each side weighing only 2 pounds, can be used for a wide variety of commercial and scientific missions, including taking pictures from space, radio communications, and atmospheric research. And because they’re built from off-the-shelf components, like the miniature electronics used in smartphones, they’re cheap. Controlling these craft once they’re in space, however, has been a problem. They don’t maneuver well and fall out of orbit quickly. In response, an MIT team has come up with a tiny version of the ion drives that are sometimes used on big satellites. The drives accelerate ions in a liquid propellant to super-high speeds to produce thrust. The researchers designed sugar-cube-size modules that contain an emitter, thruster, and propellant. Eight modules, they say, can move a CubeSat enough to boost its lifespan from months to years. Another option, the photonic laser, comes from a California company, Advanced Space and Energy Technologies. It is theoretically possible to move a tiny satellite with laser light, but the push is so anemic that it would require a hugely powerful laser. The company’s big idea, under development for the past decade with some NASA funding, is using mirrors to bounce light back and forth between the laser and the CubeSat. That amplifies the thrust of a single nudge by a factor of 1,500. A big advantage of the laser bump is not having to worry about running out of fuel. A laser-nudged CubeSat could orbit indefinitely. – T.G.
©CubeSat
Cancer Treatment
Halting Tumor Growth
Cancerous tumors grow in an acidic environment. Bioengineering researchers at Washington University in St. Louis found that nanoparticles made from calcium carbonate, the key ingredient in antacids, could stop tumor growth in its tracks by increasing the pH to more alkaline levels. The challenge was creating an injectable water-based solution. Calcium carbonate crystals resist shrinkage—they’re typically 10 to 1,000 times larger than nanoparticles needed for a therapy. Moreover, once in water, the crystals grow even bigger. Researchers ultimately developed a method to synthesize 100-nanometer crystals using ethanol-assisted diffusion, and created a solvent from albumin that keeps them from enlarging. The solution stopped tumors in mice from growing, and once researchers halted the injections, metastasis resumed. The team now hopes to discover the optimal dose to stop tumor growth and to determine if the calcium carbonate injections can be combined with chemotherapy drugs. – T.G.
©Thinkstock
Exoskeletons
Bargain Suit
Homayoon Kazerooni, a mechanical engineering professor at the University of California–Berkeley, started his spin-off company suitX as a way to develop medical exoskeletons that were not eye-poppingly expensive. He’s making progress. SuitX recently released its first product, Phoenix, a modular exoskeleton that allows people with spinal injuries to walk. It uses motorized orthotics to help the knees and hips move, with the wearer controlling the gait using push buttons in a pair of crutches. A backpack battery lasts for eight hours. Data from the Phoenix is recorded and sent to an app that a doctor or therapist can use to fine-tune the exoskeleton’s program to best suit the user’s needs. The Phoenix isn’t all that cheap—it costs $40,000—but its nearest rival, the ReWalk exoskeleton, sells for $77,000. Next, Kazerooni wants to develop a pediatric version that would help children with spinal diseases like cerebral palsy, spina bifida, or spinal muscular atrophy keep their locomotion skills intact with regular assisted walking. The Phoenix recently won the $1 million top prize at the global Robotics for Good competition in Dubai, beating out 663 entries from 121 countries. – T.G.
©SuitX/US Bionics
Flood Control
Risky Business
More than 100,000 miles of levees line America’s floodplains. And that may not be such a good thing, according to a new study led by Nicholas Pinter, a professor of earth and planetary sciences at the University of California–Davis. Pinter modeled four conditions—two-year, five-year, 100-year, and 400-year flood levels—in the Sny Island Levee Drainage District along the Mississippi River in Illinois and Missouri. That system prevents around $51 million a year in flood damages, Pinter found. But up to a third of residential structures and 22 percent of commercial buildings behind the levees faced higher flood damage risk than they would if the levees didn’t exist. That’s because of the potential for levee failure. Moreover, the study found, while levees protect one area, they can export flood risk to neighboring floodplains. Pinter says the Sny Island model is applicable to most other levee systems. Many of America’s levees are in poor shape. But, he says, that could be an opportunity to use alternative measures—including setbacks, bypass channels, flooding, and even removal. Those options, he says, could lower flood levels, recharge groundwater, and restore habitat. – T.G.
©Thinkstock
Energy Storage
Reversible Fuel Cell
A new type of fuel cell developed by aerospace giant Boeing for the U.S. Navy offers a novel way to deal with the intermittency of renewable energy sources like sunshine and wind. Fuel cells typically burn hydrogen, which, when it reacts with oxygen in the air, produces electricity and water. Typically the hydrogen is in a separate tank. But the Solid Oxide Fuel Cell devised by Boeing soaks up energy from solar or wind systems, uses that electricity to split water into its component parts, and then compresses and stores the resulting hydrogen, which can later be used to provide power when the sun isn’t shining or winds are calm. The system was successfully tested at a micro-grid station at a Navy center in California. Boeing says it can generate up to 50 kilowatts of power, and is scalable to 400 kilowatts. Another bonus: The fuel cell works with seawater, but the water that’s later released is potable. – T.G.
©Boeing
Satellite Imagery
Hidden Wonders
Aerial imagery has been a useful archaeology tool for 100 years. Back in 1906, archaeologists savored the first from-the-air photographs of Stonehenge, snapped from a balloon. Today, the big drivers in aerial imagery are satellites and unmanned aerial systems (UAS). Sarah Parcak, a space archaeologist at the University of Alabama–Birmingham, has used infrared satellite imagery to map the length and breadth of Egypt, and in the process she’s found 17 potential pyramids (there are 138 known ones), 1,000 tombs, and 3,100 settlements that were otherwise hidden, as well as the ancient Egyptian capital of Itjtawy. She recently won a $1 million TED award, which she’s using to launch an online crowd-sharing platform that will allow amateur archaeologists to use space imagery to discover sites—and keep a watchful eye out for looting. Since Egypt’s revolution in 2011, Parcak’s satellite images have shown a 400 percent to 500 percent increase in thefts at its ancient sites. Meanwhile, British scientists last year used satellite imagery to discover another row of 90 prehistoric standing stones less than two miles from Stonehenge. Another U.K. team has used customized drones in its Fossil Finder project to locate likely fossil sites in Kenya. There is big hope for greater archaeological use of drones carrying LIDAR sensors that use light to build 3-D images of a target. UAS can work well in wooded areas where the tree canopy can block satellite images. – T.G.
©Thinkstock
Unmanned Aerial Systems
The New St. Bernard
Operating unmanned aerial systems (UAS) without GPS is hard to do, but progress is being made. A team at the University of Zurich is developing a drone that can fly absent GPS over remote hiking trails to find people who get lost. Complex environments are hard for robotic aircraft computers to make sense of. The Zurich quadcopter is fitted with cameras similar to those on smartphones, but it has no sensors; instead, it uses AI algorithms to interpret the images as they’re received. But computers don’t read images all that well, either. To train the drone to make sense of images, the Swiss team used another algorithm called Deep Neural Network that learns from examples, much as humans do. The researchers hiked many trails in the Swiss Alps and took more than 20,000 images of trails from cameras on their helmets to feed to the algorithm as part of the drone’s training. It worked. When set loose along a new, previously unseen trail, the quadcopter’s algorithm found the correct way 85 percent of the time. That’s even a bit better than the human average of 82 percent. Now the team plans to teach the drone an equally important skill: the ability to recognize humans. – T.G.
©Thinkstock
Digital Voices
Ever Soft, Gentle, and Low
From our smartphones and automobile navigation systems to many interactive toys, we are increasingly listening and responding to computer-generated voices. Getting the sound just right is pretty important. In the 2013 movie Her, a lonely man ends up falling in love with the voice of his computer’s operating system. (The machine’s sultry tones actually came from actress Scarlett Johansson.) But as the New York Times reports, computer voices that are almost, but not quite, human-sounding sometimes enter the so-called uncanny valley, a speech zone that people can find disquieting. Computer programmers tell the Times the voice should not try to fool humans into thinking it’s a live being, but instead create a quasi-humanlike relationship between man and machine. The hard part is getting machines to use inflection and convey emotion correctly. Pronunciation can bedevil synthesized voices, too. Some top-end programs actually use a database filled with perhaps hundreds of hours of recordings made by human actors. “A good computer-machine interface is a piece of art and should be treated as such,” one programmer tells the newspaper. – T.G.
©Thinkstock