Vein Printer

On-demand replacement body parts inched closer to reality with the announcement from San Diego biotech company Organovo that its organ “printer” had created the first artificial blood vessel made entirely from human cells, with no synthetic scaffolding. Instead of dispensing ink, Organovo’s bioprinter uses two robotic tips to deposit globs of cells—in this case, endothelial cells that line blood-vessel walls, smooth muscle cells that regulate vessel dilation and contraction, and structural fibroblast cells. The printer takes 45 minutes to create a four-inch-long tube with a diameter of a few hundredths of an inch. Researchers flush the tube with nutrients to mimic blood flow, allowing the vessel to mature for about a month. Read...

Like Clockwork

In January 2012, the International Telecommunications Union will meet in Geneva, Switzerland, for a historic vote: Should the time of day be independent of the earth’s rotation? Since humans started keeping time, we’ve been doing it by the daily rotation and yearly revolution of the earth. But incredibly accurate modern timekeeping presents us with a problem: The official second, defined in terms of the inner workings of cesium-133 atoms, does not quite match the time required for 1/86,400 of a complete rotation of our planet, which would be the astronomically derived definition of a second. Every so often, then, a committee must add a “leap second” to the “Coordinated Universal Time” to keep the date and the planet’s orientation in order. Now some want to forgo the extra seconds. That continuity will make timekeeping easier for computers but a headache for astronomers, as the annual positions of stars in the sky will change. If the union decides to abandon the leap second, the way we track time will change in 2017. Nature has no dearth of timepieces, and the rotation of the planet and excited atoms are far from the only choices for tracking time’s passing. Here, we take a look at five natural clocks–stars and human spit included.  Read More Read...

Blood Substitutes

Earlier this month, a blood substitute called HBOC-201 made headlines when it saved an Australian woman’s life after a car crash. However, Jonathan Jahr, a professor of clinical anesthesiology at University of California, Los Angeles, says that synthetic blood has a long history: “Blood substitutes have been tested and thought about for probably a hundred years.” The basic technique that led to HBOC, or hemoglobin-based oxygen carriers, was first published in the 1930s. William Amberson, a physiologist at State College of Medicine in Memphis, Tenn., took red blood cells from cows and stripped away the cells’ coating, leaving the oxygen-carrying molecule hemoglobin. Reintroducing the hemoglobin into a patient’s blood supply proved an effective therapy, at least temporarily. At first it revitalized patients, but, in about 10 days, the small HBOC molecules caused kidney failure. Read...

Eye Chip

In the future, that twinkle in your loved one’s eye might be an implanted solar-powered pressure monitor. At the 2011 IEEE International Solid-State Circuits Conference in February, engineers from the University of Michigan, in Ann Arbor, described their work on a cubic-millimeter-size sensor meant to monitor pressure inside the eye. The researchers have yet to test the device in human eyes or animal ones, but they hope their system will one day thwart optic nerve damage brought on by glaucoma. To determine a glaucoma patient’s treatment, doctors must monitor pressure inside the eye, says Gregory Chen, a graduate student of electrical engineering at Michigan. Today’s methods gauge that pressure by pushing on the cornea, the eye’s clear outer coating. The results may be inaccurate: “If you just happen to have a really thick cornea, your eye is going to be harder, no matter what the pressure is,” Chen says. The engineers’ prototype device would allow a microelectromechanical systems (MEMS) capacitive sensor to record pressure from inside the eye about every 15 minutes and store it to static RAM. Once a day, the system would wirelessly transmit the day’s data, via two on-chip inductors, to a wand. The inductors would send the data at both 400- and 900-megahertz carrier frequencies, as a means of mitigating the signal’s noise and increasing its range. Read...

The Tide Turns

Capricious air currents and passing clouds may thwart wind and solar power, but the tides, governed by the gravitational pull of the moon and the sun, might prove a more dependable energy source. In certain spots, the tides have already proved a good source of electricity. La Rance Tidal Power Station—a barrage on the Rance River’s estuary in Brittany, France—has converted the tides’ movements into as much as 240 megawatts of electricity since 1966. But support for new projects is less predictable: Backing has ebbed for some designs, while for others it’s just starting to flow. Read...

CFL Costs

You buy a compact fluorescent lamp. The packaging says it will last for 6000 hours—about five years, if used for three hours a day. A year later, it burns out. Last year, IEEE Spectrum reported that some Europeans opposed legislation to phase out incandescent lighting. Rather than replace their lights with compact fluorescents, consumers started hoarding traditional bulbs. From the comments on that article, it seems that some IEEE Spectrum readers aren’t completely sold on CFLs either. We received questions about why the lights don’t always meet their long-lifetime claims, what can cause them to fail, and ultimately, how dead bulbs affect the advertised savings of switching from incandescent. Tests of compact fluorescent lamps’ lifetime vary among countries. The majority of CFLs sold in the United States adhere to the U.S. Department of Energy and Environmental Protection Agency’s Energy Star approval program, according to the U.S. National Electrical Manufacturers Association. For these bulbs, IEEE Spectrum found some answers. Read...

Smart Blocks

Wii-motes, Kinects, and multi-touch screens–the number of ways that gamers can control their games has certainly grown. Now, a set of smart blocks created by San Francisco start-up Sifteo, Inc., offers another way to play: by hand-arranging physical tiles, each with its own video display. Each 4.3 by 4.3 by 1.9 centimeter block weighs a mere 35 grams, but packs in a 3-axis accelerometer, a 2.4 gigahertz radio receiver and transmitter, a full-color 128 by 128 pixel LCD, an ARM micro-controller, and a Lithium-ion polymer rechargeable battery. Sifteo co-founder Jeevan Kalanithi chatted with IEEE Spectrum at last month’s 2011 Consumer Electronics Show, where the company sold its first batch of blocks as part of its Early Access program. These first sets sold-out overnight, before the show floor even opened. Kalanithi says the toy blocks take advantage of the ever-cheaper and ever-smaller components found in smartphones as well as the market’s demand for new user interfaces. See...

Dead People Science Won't Let R.I.P....

Some celebrities can’t escape the limelight, even when they’re six feet under. Whether it’s extracting their DNA, carbon dating their remains, or bombarding their hair with subatomic particles, scientists have pulled out all the stops to find and examine these historic dead. Although a bit voyeuristic, these investigations also help to distinguish likely reality from speculative rumors. So what have we learned? See...

Particle Accelerator on a Chip...

Forget for a moment about the quest to build bigger high-energy particle accelerators. Last week, at the MEMS 2011 conference, in Cancun, Mexico, researchers instead explained their efforts to create a smaller one. Their chip-size cyclotron can guide argon ions with around 1.5 kiloelectronvolts of energy down a 5-millimeter accelerating track before whipping them around a 90-degree turn. The system boosts the ions’ energy by 30 electronvolts. That’s not very much energy, but unlike its larger cousins, this accelerator has no need for bulky magnets and instead uses an electric field set up between parallel electrode guide rails to accelerate and steer its particle beam. The device’s designers at Cornell University, in Ithaca, N.Y., say that with more research, similar electrostatic mini-accelerators might be used in shoebox-size scanning electron microscopes or portable particle-ray guns for cancer treatment. Read...

Plastic Processor

Europeans announce the first organic microprocessor Take a bow, flexible chip. This week at the International Solid-State Circuits Conference, in San Francisco, European researchers will introduce the world’s first microprocessor made with organic semiconductors. The 4000-transistor, 8-bit logic circuit has the processing power of only a 1970s-era silicon model, but it has a key advantage—it can bend. The device’s designers say the chip could lead the way to cheaper flexible displays and sensors. Wrapped around pipes, for example, sheets of sensors with these processors could record average water pressure, and wrapped around food and pharmaceuticals, they might indicate that your tuna is rancid or that you forgot to take your pills. The key to the chip’s design was taming the somewhat unruly organic transistor, says Jan Genoe, a polymer and molecular electronics researcher at Belgian nanotech research center Imec, in Leuven, who led the research with colleague Kris Myny. One advantage silicon has over organics is its monocrystalline structure, which allows for well-behaved switches. If you increase the transistor gate’s voltage above a known threshold, the current turns on. But today’s organic transistors—which swap silicon for a polymer—are unpredictable. Each one can have a slightly different switching threshold. Read...

Street Canyons

Cities may feel like the antithesis of the natural world, but they obey the same rules as do the most pristine patches of wilderness. Just like mountains and valleys, buildings and pavement create their own distinctive environments—and none so distinctive as urban street canyons, the spaces between high-rises and above the streets that run between them. Studies show that the shape of street canyons (the length of blocks and the height of buildings relative to street width) strongly influence the local climate. Urban climatologists are working to predict how canyon design can affect temperatures, winds, and the concentration of pollutants. Learning how to optimize these spaces is an increasingly urgent problem: As of 2008, the urban environment has become simply “the environment” for the majority of the world’s population. Read...

Magnetic Logic Attracts Money...

DARPA funds spintronic and nanomagnet research teams to create low-power nonvolatile logic The U.S. Defense Advanced Research Projects Agency (DARPA) wants a new type of computer logic. It will rely on magnetism instead of electricity to do its job, and its developers say this difference could one day allow computers to run on a fraction of the energy now required. Some even predict that the change will make booting your computer a near instantaneous affair. The defense agency has doled out US $8.4 million for a four-year ”spintronics” project led by the University of California, Los Angeles, and $9.9 million for ”nanomagnet” research led by the University of Notre Dame. Both groups aim to build a basic magnetic logic circuit. Right now, it’s impossible to have true instant-on computers, in part because today’s volatile processors forget what they’re working on as soon as they lose power. The chips forget because they depend on the flow of electric current. When the power disappears, the flow of charge stops, as does any progress on the processing task. When the power returns, the circuit must essentially start from scratch, using information stored separately from the CPU in nonvolatile memory—and that takes time.  Read...

Next-to-the-Best Technologies of 2000-2010...

These innovations just barely missed the cut for our Top 11 list DVDs Time to Eject The rise and fall of the optical disc This year Star Wars fans will have the chance to buy yet another version of the films, this time on high-definition Blu-ray. Although the new disc may shoulder aside the DVD, it cannot equal it as a game changer. HD Radio The End of Analog AM and FM go HD In 2002, HD Radio promised Americans FM-quality sound on AM channels and CD-quality sound on FM channels—with no subscription charge. In 2006, retailers sold 28 000 HD Radio receivers for nightstands and dashboards, reports iBiquity Digital Corp., the Columbia, Md., company that developed the system. In the first three quarters of 2010, sales hit 1.2 million. Radio was finally going digital.  Read...

Leaving the Lights on...

A tour through a center that tests CFLs, LEDs, and human health Jeremy Snyder: “You used to go into the hardware store or grocery store, your lightbulb at home is burnt out, so you just reach on the shelf and grab another one. And now the choices are getting slightly more complicated, and people are going to have to start making some evaluations.” Energy-efficient compact fluorescent bulbs and light-emitting diodes are starting to replace incandescent lights around the world. But their complicated electronics mean they won’t perform exactly like their predecessors. Here, at the Rensselaer Polytechnic Institute’s Lighting Research Center, in Troy, N.Y., researchers run a new generation of bulbs through a gauntlet of different tests. They want to help consumers make more informed lighting choices. Jeremy Snyder: “Sure, you could say, ‘Take out whatever lamp you have now and put in the most efficient light source.’ Well, if that doesn’t work for the people in that environment, then it’s not going to work at all. People are going to switch back.” Jeremy Snyder works in this nationally accredited laboratory. In some ways it’s a lightbulb infirmary. Computers connect to large racks of lamps. They can monitor bulbs’ vital signs, like power, and sometimes, time of death. Each technology has its own weaknesses. For example, CFLs don’t live as long when they’re switched on and off repeatedly. This stresses the lamp’s electronics.  See...

Solar Sailing

Several solar sails are set for launch John F. Kennedy called space “this new ocean.” This year, we’re finally starting to sail on it. In May, Japan’s space agency launched a craft that steals momentum from energetic photons blowing off the sun for a free ride through the solar system. The concept isn’t exactly new. Back in 1974, NASA’s Mariner 10 spacecraft used the light hitting its solar arrays to adjust its angle on the way to Mercury. Given Japan’s success, sailing prospects seem better than ever. NASA plans to launch a sail this year, and in 2011, the Planetary Society expects its own craft will be ready to fly. By the 2030s, the European company Thales Alenia Space hopes to launch “data clippers”—essentially sailing hard drives that could shuttle data between probes exploring Saturn’s and Jupiter’s moons and Earth. Read...

Engineers to Implant Antivertigo Device...

Vestibular prosthesis is a pacemaker for the inner ear Tomorrow, 21 October, a surgeon will attempt to fight debilitating vertigo by rewiring the body’s balance center. Jay Rubinstein, a surgeon and biomedical engineer at the University of Washington, in Seattle, will insert a “vestibular prosthesis” inside his patient’s head, weaving electrode arrays into the depths of the inner ear. He hopes that pulses from these electrodes will stop vomit-inducing dizziness caused by Ménière’s disease. “When a Ménière’s attack occurs, you basically have to lie down and curl up into a ball,” Rubinstein says. “It’s not very conducive to a productive existence if these are happening once a week.” For most, diet changes and diuretics can stop the attacks by lowering inner ear pressure, but about 15 percent of patients require surgery to decrease the sensitivity of the inner ear—and the most severe cases require disconnecting nerves to the inner ear altogether. “If the alternative is to go in and kill your ear,” says James Phillips, a vestibular neurophysiologist at the University of Washington who developed the device with Rubinstein, “then maybe it makes sense to provide a prosthesis.” Read...

Brain Beauty Contest

Computer modelers compete to show neurosurgeons the best path to the tumor Plotting the path to a brain tumor first requires a map. As part of next week’s VisWeek conference, the 2010 IEEE Visualization Contest pitted graphics teams from both industry and academia against one another to see who could best draw that map. Each team transformed the same sets of MRI data into unique, and sometimes bizarre, pictures of the safest paths through the brain. Neurosurgeons decided the winner. See...

Finding Subatomic Particles...

Using the world’s most powerful particle accelerators and sophisticated detectors, physicists are searching for traces of the Higgs boson, the particle that could help us understand how the universe got its mass. Fermilab’s Tevatron and CERN’s Large Hadron Collider are the front-runners for finding this last missing member of the particle family, as described by physicists’ Standard Model of the particle world. In July 2010, the Tevatron found another clue, narrowing the expected range of the hypothetical Higgs boson’s mass. Meanwhile, researchers at the LHC, the younger but more powerful of the accelerator pair, announced that it rediscovered in just months particles that previous detectors had taken decades to find. CERN’s Director-General Rolf Heuer said: “Rediscovering our ‘old friends’ in the particle world shows that the LHC experiments are well prepared to enter new territory…. Now it is down to nature to show us what is new.” But how did physicists first make these particles’ acquaintances? Here are several proven techniques for would-be particle hunters. Read...

80beats: Did Earth’s Magnetic Field Have a Fast Flip-Flop?...

Had compass-toting Boy Scouts existed around fifteen million years ago, they may have had a fun time making it through the forest. New geological research questions if the Earth’s magnetic field changed, at that time, at the remarkable pace of one degree per week, leading to a particularly fast magnetic pole flip. In a paper to appear in Geophysical Research Letters, Scott Bogue and Jonathan Glen suggest that the Earth’s magnetic field changed 53 degrees in one year’s time, based on their study of preserved lava flows in Nevada. As the solid rock formed from cooling liquid lava, it preserved a pattern corresponding to the “super-fast” geomagnetic field reversal, the researchers believe. This is the second time that Bogue has controversially argued for the existence of such speedy flips, finding hints of a faster one in 1995. Read...

80beats: How a Massive Star Is Born...

Our sun and a much bigger star that resides 10,000 light years away have something in common: the way they were born. Though scientists had previously wondered if stars 10 to 20 times the sun’s size required a different setup to grow, new observations show that both our sun and plus-sized stars can form from large hoops of dust called accretion disks. Astronomers arrived at the findings, published online today in Nature, by weaving together observations from two observatories–the Very Large Telescope Interferometer of the European Southern Observatory in Chile and NASA’s orbital Spitzer Space Telescope. Researchers combined the observatories’ power to get a “virtual” telescope of much better resolution, the equivalent of one with a 280-foot mirror. Lead researcher Stefan Kraus and his colleagues took a close peek at a 60,000-year-old stellar infant about 20 times our sun’s mass, called IRAS 13481-6124. The researchers were able to piece together temperature data to make a model of stellar birth that might resemble something from our 4.6 billion-year-old sun’s baby-book. Read...

Slow Burn

Since 1962, a coal fire has been raging beneath Centralia, Pennsylvania, and it may continue burning for centuries. When the very ground beneath your feet catches fire, how can you extinguish the blaze? Tourists drive for hours to Columbia County, hoping to find in a former mining town scenes of hell incarnate. They are disappointed. In 1962, a small community in rural Pennsylvania prepared for a Memorial Day celebration. On the town’s edge, near the Odd Fellows Cemetery, sat an old mining pit turned municipal landfill. To control its smell and vermin, the story goes, volunteer firefighters set a small fire in the trash, let it burn for a few hours, and, after dousing the flames with water, left a smoking pit. Today, on what was once Route 61 just outside town, appears a spray-painted greeting:  “Welcome to Graffiti Highway.” About twenty feet down the road, smoke rises, almost imperceptibly, from a buckle in the paved sea of heart-encircled initials and crossed-out phone numbers. Some believe that Memorial Day trash fire ignited a seam of coal, the Buck Mountain vein, and started an underground inferno that still burns. If no one stops it—and no one plans to—some geologists estimate that it could continue burning for another two centuries. Read...

Reinventing the Wheel...

Can MIT’s Green Wheel or Copenhagen Wheel reinvent the bicycle? Can they reinvent the city? Find out in a short documentary by Joe Calamia, Josh Feblowitz, Nidhi Subbaraman and Morgan Sherburne.  See...

You Are Not A Gadget

If you bought a Windows computer in the late 1990s, perhaps you remember the system’s preloaded music. Beethoven’s “Fifth Symphony,” Bach’s “Brandenburg Concerto Number Three,” Tchaikovsky’s “Dance of the Sugarplum Fairies”—Windows Media Player included them all, along with two songs created by Microsoft called “Passport” and “Canyon,” the apparent digital love children of elevator music and 1980s advertising jingles. Though any listener could recognize the classics’ melodies, each note sounded somehow mechanical, and certainly simplified. In his first book, You Are Not a Gadget: A Manifesto, Jaron Lanier uses the birth of these songs as one example in his intriguing investigation into culture’s current relationship with technology. The songs use a programming strategy called MIDI to make music. MIDI stands for Musical Instrument Digital Interface, which simplifies music’s complexity into discrete steps in pitch. Dave Smith, a synthesizer designer, devised MIDI in the 1980s, but we still find MIDI songs everywhere from digital alarm clocks to cell phone ringtones. Certainly, they are no longer the best available strategy, but, Lanier argues, they have become a “locked-in” design, an assumed and arbitrary rule in computer programming. Read...

Streetcars and Corpuscles...

In 1705, light was a particle. In 1805, light was a wave. In 1905, light was a particle. “I no longer doubt the reality of light quanta,” Albert Einstein wrote in a July 1918 letter to friend Michele Besso, “although I still stand quite alone in this conviction.” Given light’s historic identity crisis, it is not hard to imagine why. In 1922, both Neils Bohr and Einstein received the Nobel Prize in Physics: Bohr for his work explaining radiation and the structure of atoms, and Einstein (a belated 1921 award) for what is called the photoelectric effect, demonstrating that light must be a particle. Despite Einstein’s work, Bohr was not convinced: “I shall not . . . discuss the familiar difficulties to which the hypothesis of ‘light quanta’ leads,” he said. Louisa Gilder uses both of these quotes in her book The Age of Entanglement: When Quantum Physics was Reborn. Later she describes a debate between Bohr and Einstein in 1920 as they rode a Copenhagen streetcar. The discussion grew so heated, Bohr recalled in a 1961 interview, that the men kept missing their stop: “We took the streetcar from the station and talked so animatedly about things that we went much too far past our destination . . . We went back and forth . . . what people thought of us, that is something else.” Read...