Meet the Nimble-Fingered Interface of the Future

Microsoft's Kinect, a 3-D camera and software for gaming, has made a big impact since its launch in 2010. Eight million devices were sold in the product's.....

Electronic Implant Dissolves in the Body

Researchers at the University of Illinois at Urbana-Champaign, Tufts University, and ......

Sorting Chip May Lead to Cell Phone-Sized Medical Labs

The device uses two beams of acoustic -- or sound -- waves to act as acoustic tweezers and sort a continuous flow of cells on a ....

TDK sees hard drive breakthrough in areal density

Perpendicular magnetic recording was an idea that languished for many years, says a TDK technology backgrounder, because the ....

Engineers invent new device that could increase Internet

The device uses the force generated by light to flop a mechanical switch of light on and off at a very high speed........

Using light to control light: Engineers invent new device that could increase Internet download speeds

The device uses the force generated by light to flop a mechanical switch of light on and off at a very high speed. This development could lead to advances in computation and signal processing using light instead of electrical current with higher performance and lower power consumption. The research results were published today in the online journal Nature Communications.

University of Minnesota researchers have invented a novel microscale mechanical switch of light on a silicon chip.

"This device is similar to electromechanical relays but operates completely with light," said Mo Li, an assistant professor of electrical and computer engineering in the University of Minnesota's College of Science and Engineering.

The new study is based on a previous discovery by Li and collaborators in 2008 where they found that nanoscale light conduits can be used to generate a strong enough optical force with light to mechanically move the optical waveguide (channel of information that carries light). In the new device, the researchers found that this force of light is so strong that the mechanical property of the device can be dominated completely by the optical effect rather than its own mechanical structure. The effect is amplified to control additional colored light signals at a much higher power level.

"This is the first time that this novel optomechanical effect is used to amplify optical signals without converting them into electrical ones," Li said.

Glass optical fibers carry many communication channels using different colors of light assigned to different channels. In optical cables, these different-colored light channels do not interfere with each other. This non-interference characteristic ensures the efficiency of a single optical fiber to transmit more information over very long distances. But this advantage also harbors a disadvantage. When considering computation and signal processing, optical devices could not allow the various channels of information to control each other easily…until now.

The researchers' new device has two optical waveguides, each carrying an optical signal. Placed between the waveguides is an optical resonator in the shape of a microscale donut (like a mini-Hadron collider.) In the optical resonator, light can circulate hundreds of times gaining intensity.

Using this resonance effect, the optical signal in the first waveguide is significantly enhanced in the resonator and generates a very strong optical force on the second waveguide. The second waveguide is released from the supporting material so that it moves in oscillation, like a tuning fork, when the force is applied on it. This mechanical motion of the waveguide alters the transmission of the optical signal. Because the power of the second optical signal can be many times higher than the control signal, the device functions like a mechanical relay to amplify the input signal.

Currently, the new optical relay device operates one million times per second. Researchers expect to improve it to several billion times per second. The mechanical motion of the current device is sufficiently fast to connect radio-frequency devices directly with fiber optics for broadband communication.

Li's team at University of Minnesota includes graduate students Huan Li, Yu Chen and Semere Tadesse and former postdoctoral fellow Jong Noh. Funding support of the project came from the University of Minnesota College of Science and Engineering and the Air Force Office of Scientific Research.

From phys

Engineers collaborate on inexpensive DNA sequencing method

While sequencing the genome of an animal species for the first time is so common that it hardly makes news anymore, it is less well known that sequencing any single individual's DNA is an expensive affair, costing many thousands of dollars using today's technology. An individual's genome carries markers that can provide advance warning of the risk of disease, but you need a fast, reliable and economical way of sequencing each patient's genes to take full advantage of them. Equally important is the need to continually sequence an individual's DNA over his or her lifetime, because the genetic code can be modified by many factors.

Schematic of an artificial membrane, across which a voltage forces an ionized fluid through the nanopore. Nucleotides on a strand of DNA are first tagged with different-sized polymers, and then the strand is passed near the nanopore opening, where a polymerase cleaves the polymers and passes them one by one through the nanopore. As they pass, the pore produces a unique ionic current blockade signature due to the tag's distinct chemical structure, thereby determining DNA sequence.

Read more at:
Schematic of an artificial membrane, across which a voltage forces an ionized fluid through the nanopore. Nucleotides on a strand of DNA are first tagged with different-sized polymers, and then the strand is passed near the nanopore opening, where a polymerase cleaves the polymers and passes them one by one through the nanopore. As they pass, the pore produces a unique ionic current blockade signature due to the tag's distinct chemical structure, thereby determining DNA sequence.
Schematic of an artificial membrane, across which a voltage forces an ionized fluid through the nanopore. Nucleotides on a strand of DNA are first tagged with different-sized polymers, and then the strand is passed near the nanopore opening, where a polymerase cleaves the polymers and passes them one by one through the nanopore. As they pass, the pore produces a unique ionic current blockade signature due to the tag's distinct chemical structure, thereby determining DNA sequence.

Read more at:

The new method determines DNA sequences by attaching distinct molecular "tags" to each of the four chemical building blocks, or "bases," that comprise the genetic information in a strand of DNA—abbreviated as A, G, C and T. Each of these polymer tags can then be cut from the strand and passed, one by one, through a nanometer-size hole in a membrane. A steady stream of fluid and ions flows through this "nanopore," which is large enough to contain only one tag at a time. As the polymer tags are different sizes, the change in electrical current caused by altered fluid flow shows which of the four bases sits at each point on the DNA strand.

Nanopores and their interaction with polymer molecules have been a longtime research focus of NIST scientist John Kasianowicz. His group collaborated with a team led by Jingyue Ju, director of Columbia's Center for Genome Technology and Biomolecular Engineering, which came up with the idea for tagging DNA building blocks for single molecule sequencing by nanopore detection. The ability to discriminate between the polymer tags was demonstrated by Kasianowicz, his NIST colleague Joseph Robertson, and others. Columbia University has applied for patents for the commercialization of the technology.

Kasianowicz estimates that the technique could identify a DNA building block with extremely high accuracy at an error rate of less than one in 500 million, and the necessary equipment would be within the reach of any medical provider. "The heart of the sequencer would be an operational amplifier that would cost much less than $1,000 for a one-time purchase," he says, "and the cost of materials and software should be trivial."

Kasianowicz adds that a private company might create a large array of nanopores that can analyze a single individual's genome cut up into many short strands of DNA, each of which could be sequenced quickly. Such an array potentially could provide the low-cost sequencing needed for routine medical use.

From phys

TDK sees hard drive breakthrough in areal density

Perpendicular magnetic recording was an idea that languished for many years, says a TDK technology backgrounder, because the complexity of high-density magnetic recording technology stymied commercial development. "This method demands highly sophisticated thin-film process technologies to form microscopic single poles between multiple thin layers. Beyond that, a number of complex issues arise when trying to miniaturize single poles," said TDK. "One particularly difficult problem is overcoming pole erasure, the deletion of magnetic data due to remanent magnetization at the tip of the pole." 

 The magnetic head for thermal assist recording. Credit: via Tech-on.

As magnetic head manufacturers, TDK says it is now drawing on nano-level thin-film multilayering and processing technologies that clear the technological hurdles one by one. TDK features a Tunneling Magneto-Resistance (TMR) head , which uses thermal assist recording and a near-light field. (Researchers from Hitachi describe thermally assisted recording as an extension to perpendicular magnetic recording. In thermally-assisted recording, says Hitachi, magnetic grains can be made smaller while still resisting thermal fluctuations at room temperature.) Consumers are to see these hard drives using thermal assisted magnetic heads in 2014. Before that, though, 

TDK will officially unveil its new hard-drive technology this week at CEATEC Japan 2012. At CEATEC, the company will also show a thermal assist recording method based on near-field light by using an actual HDD supporting the method. A significant side story belongs to Showa Denko, which, among other divisions, engages in hard disk media. Showa Denko also has a confident grasp of the disk drive market: "We expect that demand for hard disk drives (HDDs) will continue to grow by about 10 percent annually. " Hard disk drives for years have been a dominant device for storage of data. Greater capacities and lower prices have kept the hard drive from falling victim to SSD technology. Showa Denko believes HDDs still have nowhere to go but up because of notebook demand, cloud computing, and current requirements for high-capacity servers at data centers, expected to increase. To meet the demand, the company intends to "speedily commercialize the sixth-generation PMR (perpendicular magnetic recording) media, and develop the next-generation SWR (shingled-write recording) media."

From phys

Acoustic Cell-Sorting Chip May Lead to Cell Phone-Sized Medical Labs

The device uses two beams of acoustic -- or sound -- waves to act as acoustic tweezers and sort a continuous flow of cells on a dime-sized chip, said Tony Jun Huang, associate professor of engineering science and mechanics, Penn State. By changing the frequency of the acoustic waves, researchers can easily alter the paths of the cells.

 Slightly larger than a dime, this cell-sorting device uses two sound beams to act as acoustic tweezers.

Huang said that since the device can sort cells into five or more channels, it will allow more cell types to be analyzed simultaneously, which paves the way for smaller, more efficient and less expensive analytic devices.

"Eventually, you could do analysis on a device about the size of a cell phone," said Huang. "It's very doable and we're making in-roads to that right now."

Biological, genetic and medical labs could use the device for various types of analysis, including blood and genetic testing, Huang said.

Most current cell-sorting devices allow the cells to be sorted into only two channels in one step, according to Huang. He said that another drawback of current cell-sorting devices is that cells must be encapsulated into droplets, which complicates further analysis.

"Today, cell sorting is done on bulky and very expensive devices," said Huang. "We want to minimize them so they are portable, inexpensive and can be powered by batteries."

Using sound waves for cell sorting is less likely to damage cells than current techniques, Huang added.

In addition to the inefficiency and the lack of controllability, current methods produce aerosols, gases that require extra safety precautions to handle.

The researchers, who released their findings in the current edition of Lab on a Chip, created the acoustic wave cell-sorting chip using a layer of silicone -- polydimethylsiloxane. According to Huang, two parallel transducers, which convert alternating current into acoustic waves, were placed at the sides of the chip. As the acoustic waves interfere with each other, they form pressure nodes on the chip. As cells cross the chip, they are channeled toward these pressure nodes.

The transducers are tunable, which allows researchers to adjust the frequencies and create pressure nodes on the chip.

The researchers first tested the device by sorting a stream of fluorescent polystyrene beads into three channels. Prior to turning on the transducer, the particles flowed across the chip unimpeded. Once the transducer produced the acoustic waves, the particles were separated into the channels.

Following this experiment, the researchers sorted human white blood cells that were affected by leukemia. The leukemia cells were first focused into the main channel and then separated into five channels.

The device is not limited to five channels, according to Huang.
"We can do more," Huang said. "We could do 10 channels if we want, we just used five because we thought it was impressive enough to show that the concept worked."

Huang worked with Xiaoyun Ding, graduate student, Sz-Chin Steven Lin, postdoctoral research scholar, Michael Ian Lapsley, graduate student, Xiang Guo, undergraduate student, Chung Yu Keith Chan, doctoral student, Sixing Li, doctoral student, all of the Department of Engineering Science and Mechanics at Penn State; Lin Wang, Ascent BioNano Technologies; and J. Philip McCoy, National Heart, Lung and Blood Institute, National Institutes of Health.

The National Institutes of Health Director's New Innovator Award, the National Science Foundation, Graduate Research Fellowship and the Penn State Center for Nanoscale Science supported this work.

From sciencedaily

Thanks for the Transparent Memories: Progress in Quest for Reliable, Flexible Computer Memory for Transparent Electronics

This happens even when the work of art is on the nanoscale, where individual things make a strand of hair look like a redwood by comparison.

More than four years ago, a collection of students, postdoctoral researchers and professors at Rice University found themselves chiseling down into a mystery involving two of the most basic, common elements on Earth: carbon and silicon oxide.

Using graphene as crossbar terminals, Rice researchers are following through on groundbreaking research that shows silicon oxide, one of the most common materials on Earth, can be used as a reliable computer memory. The memories are flexible, transparent and can be built in 3-D configurations.

The group led by chemist James Tour came to a discovery of note: that it was possible to make bits of computer memory from those elements, but make them much smaller and perhaps better than anything on the market even today.

From that first revelation in 2008 to now, Tour and his team have steadily advanced the science of two-terminal memory devices, which he fully expects will become ubiquitous in the not-too-distant future.

The latest dispatch is a paper in the journal Nature Communications that describes transparent, non-volatile, heat- and radiation-resistant memory chips created in Tour's lab from those same basic elements, silicon and carbon. But a lot has happened since 2008, and these devices bear only a passing resemblance to the original memory unit.

In the new work, Tour and his co-authors detail their success at making memory chips from silicon oxide sandwiched between electrodes of graphene, the single-atom-thick form of carbon.

Even better, they were able to put those test chips onto flexible pieces of plastic, leading to paper-thin, see-through memories they hope can be manufactured with extraordinarily large capacities at a reasonable price. Think about what that can do for heads-up windshields or displays with embedded electronics, or even flexible, transparent cellphones.

"The interest is starting to climb," said Tour, Rice's Rice's T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science. "We're working with several companies that are interested either in getting their chips to do this kind of switching or in the possibility of making radiation-hard devices out of this."

In fact, samples of the chips have climbed all the way to the International Space Station (ISS), where memories created and programmed at Rice are being evaluated for their ability to withstand radiation in a harsh environment.

"Now, we've seen a couple of DARPA announcements asking for proposals for devices based on silicon oxide, the very thing we've shown. So there are other people seeing the feasibility of this approach," Tour said.

It wasn't always so, even if silicon oxide "is the most studied material in humankind," he said.
"Labs in the '60s and '70s that saw the switching effect didn't have the tools to understand what they were looking at," he said. "They didn't know how to exploit it; they called it a soft breakdown in silicon. To them, it was something bad."

In the original work at Rice, researchers put strips of graphite, the bulk form of carbon best known as pencil lead, across a silicon oxide substrate and noticed that applying strong voltage would break the carbon; lower voltages would repeatedly heal and re-break the circuit. They recognized a break could be a "0″ and a healed circuit a "1." That's a switch, the most basic memory state.

Manufacturers who have been able to fit millions of such switches on small devices in the likes of flash memory now find themselves bumping against the physical limits of their current architectures, which require three wires -- or terminals -- to control and read each bit.

But the Rice unit, requiring only two terminals, made it far less complicated. It meant arrays of two-terminal memory could be stacked in three-dimensional configurations that would vastly increase the amount of information a chip could hold.

And best of all, the mechanism that made it possible turned out not to be in the graphite, but the silicon oxide. In the breakthrough 2010 paper that followed the 2008 discovery, the researchers led by then-graduate student Jun Yao found that a strong jolt of voltage through a piece of silicon oxide stripped oxygen atoms from a channel only 5 nanometers wide, turning it into pure silicon. Lower voltages would break the channel or reconnect it, repeatedly, thousands of times.

"Jun was the first to recognize what he was seeing," Tour said. "Nobody believed him, though (Rice physicist) Doug Natelson said, 'You know, it's not out of the realm of possibility.' The people on the graphitic memory project were not at all excited about him saying this and they argued with Jun tooth and nail for a couple of years."

Yao struggled to convince his lab partners the switching effect wasn't due to the breaking graphite but to the underlying crystalline silicon. "Jun quietly continued his work and stacked up evidence, eventually building a working device with no graphite," Tour said. Still, he recalled, Yao's colleagues suspected that carbon in the system skewed the results. So he demonstrated another device with no possible exposure to carbon at all.

Yao's revelation became the basis for the next-generation memories now being designed in Tour's lab, where silicon oxides sandwiched between graphene layers are being attached to plastic sheets. There's not a speck of metal in the entire unit (with the exception of leads attached to the graphene electrodes). And the eye can see right through it.

"Now we're making these memories with about an 80 percent yield of working devices, which is pretty good for a non-industrial lab," Tour said. "When you get these ideas into industries' hands, they really sharpen it up."

The idea of transparency came later. "Silicon oxide is basically the same material as glass, so it should be transparent," Tour said. Graphene sheets, single-atom-thick carbon honeycombs, are almost completely transparent, too, and tests detailed in the new paper showed their ability to function as crossbar electrodes, a checkerboard array half above and half below the silicon oxide that creates a circuit where the lines intersect.

The marriage of silicon and graphene would extend the long-recognized utility of the first and prove once and for all the value of the second, long touted as a wonder material looking for a reason to be.
"It was a very rewarding experience," said Yao, now a postdoctoral researcher at Harvard, of his work at Rice. "I feel grateful that I stumbled on this, had the support of my advisers and persisted."

By good fortune, Yao was the rare graduate student with three advisers. As confusing as that may have seemed at the start of his Rice career, it was luck those advisers were digital systems expert Lin Zhong and condensed matter physicist Natelson, both rising stars in their fields, and Tour, a renowned chemist.

Each made important contributions to the project as it progressed. "Doug had very acute intuition about the underlying mechanism, and we constantly turned to Lin for his advice on the electronic architecture," Yao said.

Getting his story on Page 1 of the New York Times was enough of a thrill, but another was ahead as NASA decided to include samples of his chip in an experimental package bound for the space station. The day of Yao's planned departure for his postdoctoral job in Cambridge, Aug. 24, 2011, was to be the best of all as the HIMassSEE project lifted off from Central Asia aboard a cargo flight to the ISS. Minutes later, the unmanned craft crashed in Siberia.

Nearly a year later, a new set of chips made it to the ISS, where they will stay for two years to test their ability to hold a pattern when exposed to radiation in space.

In the meantime, Yao passed responsibility for the project to Jian Lin, a co-author of the new paper who joined the Tour and Natelson labs in 2011 as a postdoctoral researcher. Lin built the latest iterations of silicon oxide memories using crossbar graphene electrodes.

"Our lab members are excellent at synthesizing materials and I'm good at fabrication of devices for various applications, so we work together well," said Lin, whose primary interest is in the application of nanomaterials. "This group is a win-win for me."

Labs at other institutions have picked up the thread, carrying out their own experiments on silicon oxide memory. "The switching mechanism has pretty much been investigated," Lin said. "But from engineering or application perspectives, there are a lot of things that can be done."

So here silicon memory stands, a toddler full of promise. Researchers at Rice and elsewhere are working to increase silicon memory's capacity and improve its reliability while electronics manufacturers think hard about how to make it in bulk and put it into products.

Tour realizes impatience for scientific progress is a function of hurried times and not a failure of the process, but he counsels against frustration. "It's a very interesting system that has been slow to develop," he said, "as we've been working to understand the fundamental switching mechanism," a task largely accomplished by Yao and his Rice advisers in a paper published earlier this year. "This is now transitioning slowly into an applied system that could well be taken up as a future memory system.

"It is a good example of basic research," he said. "Now, others have to be able to look forward from the science and say, 'You know, there's a path to a product here.'"

Co-authors of the Nature Communications paper are Rice graduate students Yanhua Dai, Gedeng Ruan, Zheng Yan and Lei Li. Zhong is an associate professor of electrical and computer engineering. Natelson is a professor of physics and astronomy and of electrical and computer engineering.

The research was supported by the David and Lucille Packard Foundation, the Texas Instruments Leadership University Fund, the National Science Foundation and the Army Research Office.

From sciencedaily

Superman-Strength Bacteria Produce 24-Karat Gold

"Microbial alchemy is what we're doing -- transforming gold from something that has no value into a solid, precious metal that's valuable," said Kazem Kashefi, assistant professor of microbiology and molecular genetics.

 A bioreactor uses a gold-loving bacteria to turn liquid gold into useable, 24-karat gold.

He and Adam Brown, associate professor of electronic art and intermedia, found the metal-tolerant bacteria Cupriavidus metallidurans can grow on massive concentrations of gold chloride -- or liquid gold, a toxic chemical compound found in nature.

In fact, the bacteria are at least 25 times stronger than previously reported among scientists, the researchers determined in their art installation, "The Great Work of the Metal Lover," which uses a combination of biotechnology, art and alchemy to turn liquid gold into 24-karat gold. The artwork contains a portable laboratory made of 24-karat gold-plated hardware, a glass bioreactor and the bacteria, a combination that produces gold in front of an audience.

Brown and Kashefi fed the bacteria unprecedented amounts of gold chloride, mimicking the process they believe happens in nature. In about a week, the bacteria transformed the toxins and produced a gold nugget.

"The Great Work of the Metal Lover" uses a living system as a vehicle for artistic exploration, Brown said.

In addition, the artwork consists of a series of images made with a scanning electron microscope. Using ancient gold illumination techniques, Brown applied 24-karat gold leaf to regions of the prints where a bacterial gold deposit had been identified so that each print contains some of the gold produced in the bioreactor.

"This is neo-alchemy. Every part, every detail of the project is a cross between modern microbiology and alchemy," Brown said. "Science tries to explain the phenomenological world. As an artist, I'm trying to create a phenomenon. Art has the ability to push scientific inquiry."

It would be cost prohibitive to reproduce their experiment on a larger scale, he said. But the researchers' success in creating gold raises questions about greed, economy and environmental impact, focusing on the ethics related to science and the engineering of nature.

"The Great Work of the Metal Lover" was selected for exhibition and received an honorable mention at the cyber art competition, Prix Ars Electronica, in Austria, where it's on display until Oct. 7. Prix Ars Electronica is one of the most important awards for creativity and pioneering spirit in the field of digital and hybrid media, Brown said.

"Art has the ability to probe and question the impact of science in the world, and 'The Great Work of the Metal Lover' speaks directly to the scientific preoccupation while trying to shape and bend biology to our will within the postbiological age," Brown said.

From sciencedaily

Electronic Implant Dissolves in the Body

Researchers at the University of Illinois at Urbana-Champaign, Tufts University, and others have created fully biodegradable electronics that could allow doctors to implant medical sensors or drug delivery devices that dissolve when they're no longer needed. The transient circuits, described in today's issue of Science, can be programmed to disappear after a set amount of time based on the durability of their silk-protein coating. 

 Soluble silicon: This electronic circuit dissolves when exposed to water. 

"You want the device to serve a useful function, but after that function is completed, you want it to simply disappear by dissolution and resorption into the body," says John Rogers, a physical chemist at the University of Illinois at Urbana-Champaign and senior author on the study.  

The authors demonstrate this possibility with a resorbable device that can heat the area of a surgical cut to prevent bacterial growth. They implanted the heat-generating circuit into rats. After three weeks, the authors examined the site of the implant and found that the device had nearly completely disappeared, leaving only remnants of the silk coating, which is eliminated more slowly than the silicon and magnesium of the circuit itself.

The work builds upon previous efforts from Tufts University's Fiorenzo Omenetto (whose work won a 10 Emerging Technologies award in 2010) on using silk as a body-friendly mechanical support for electronics as well as a tunable coating that can be made to last days or months depending on chemical processing. By combining that technology with their own thin and flexible circuitry, Omenetto, Rogers, and the rest of their team were able to develop silicon-based electronics that completely biodegrade. Other groups are also working to develop biodegradable electronics, some with different materials that may not perform as reliably as the silicon device but might dissolve faster.

"The basic idea is to fabricate implants that are not only electronically active but that can degrade over time," says Chris Bettinger, a materials scientist at Carnegie Mellon University who is also developing such electronics. "Integration, I think, is the achievement here," he says of the study. "It's really impressive, with regards to how they were able to integrate all the materials."

The circuits themselves are made from magnesium electrodes and thin sheets of silicon. They are built on a support substrate of protein purified from silkworm silk. The thin silicon sheets, or nanomembranes, are an important part of the integrated technology, says Bettinger, because they are more flexible and easily broken down and eliminated by the body than other forms of the semiconductor.

The technology could be useful in a variety of biomedical implants, from treating surgical infections, as demonstrated, to drug delivery or disease diagnostics. But the potential extends beyond the body, says Rogers. "Environmental monitors or even consumer electronics might be interesting to build in this fashion, because it would help to eliminate a lot of waste streams with discarded electronics," he says.

By Susan Young  
From Technology Review

Meet the Nimble-Fingered Interface of the Future

Microsoft's Kinect, a 3-D camera and software for gaming, has made a big impact since its launch in 2010. Eight million devices were sold in the product's first two months on the market as people clamored to play video games with their entire bodies in lieu of handheld controllers. But while Kinect is great for full-body gaming, it isn't useful as an interface for personal computing, in part because its algorithms can't quickly and accurately detect hand and finger movements. 

 Finger mouse: 3Gear uses depth-sensing cameras to track finger movements.

Now a San Francisco-based startup called 3Gear has developed a gesture interface that can track fast-moving fingers. Today the company will release an early version of its software to programmers. The setup requires two 3-D cameras positioned above the user to the right and left. 

The hope is that developers will create useful applications that will expand the reach of 3Gear's hand-tracking algorithms. Eventually, says Robert Wang, who cofounded the company, 3Gear's technology could be used by engineers to craft 3-D objects, by gamers who want precision play, by surgeons who need to manipulate 3-D data during operations, and by anyone who wants a computer to do her bidding with a wave of the finger.

One problem with gestural interfaces—as well as touch-screen desktop displays—is that they can be uncomfortable to use. They sometimes  lead to an ache dubbed "gorilla arm." As a result, Wang says, 3Gear focused on making its gesture interface practical and comfortable. 

"If I want to work at my desk and use gestures, I can't do that all day," he says. "It's not precise, and it's not ergonomic." 

The key, Wang says, is to use two 3-D cameras above the hands. They are currently rigged on a metal frame, but eventually could be clipped onto a monitor. A view from above means that hands can rest on a desk or stay on a keyboard. (While the 3Gear software development kit is free during its public beta, which lasts until November 30, developers must purchase their own hardware, including cameras and frame.)

"Other projects have replaced touch screens with sensors that sit on the desk and point up toward the screen, still requiring the user to reach forward, away from the keyboard," says Daniel Wigdor, professor of computer science at the University of Toronto and author of Brave NUI World, a book about touch and gesture interfaces. "This solution tries to address that."

3Gear isn't alone in its desire to tackle the finer points of gesture tracking. Earlier this year, Microsoft released an update that enabled people who develop Kinect for Windows software to track head position, eyebrow location, and the shape of a mouth. Additionally, Israeli startup Omek, Belgian startup SoftKinetic, and a startup from San Francisco called Leap Motion—which claims its small, single-camera system will track movements to a hundredth of a millimeter—are all jockeying for a position in the fledgling gesture-interface market. 

"Hand tracking is a hard, long-standing problem," says Patrick Baudisch, professor of computer science at the Hasso-Plattner Institute in Potsdam, Germany. He notes that there's a history of using cumbersome gloves or color markers on fingers to achieve this kind of tracking. An interface without these extras is "highly desirable," Baudisch says.

3Gear's system uses two depth cameras (the same type used with Kinect) that capture 30 frames per second. The position of a user's hands and fingers are matched to a database of 30,000 potential hand and finger configurations. The process of identifying and matching to the database—a well-known approach in the gesture-recognition field—occurs within 33 milliseconds, Wang says, so it feels like the computer can see and respond to even a millimeter finger movement almost instantly.

Even with the increasing interest in gesture recognition for hands and fingers, it may take time for non-gamers and non-engineers to widely adopt the technology. 

"In the desktop space and productivity scenario, it's a much more challenging sell," notes Johnny Lee, who previously worked at Microsoft on the Kinect team and now works at Google. "You have to compete with the mouse, keyboard, and touch screen in front of you." Still, Lee says, he is excited to see the sort of applications that will emerge as depth cameras drop in price, algorithms for 3-D sensing continue to improve, and more developers see gestures as a useful way to interact with machines. 

By Kate Greene  
From Technology Review