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Sony Creates Curved CMOS Sensors That Mimic the Eye

The retinas of humans and other animals line the curved inner surface of the eye. Now, in a bit of biomimicry, Sony engineers report that they have created a set of curved CMOS image sensors using a "bending machine" of their own construction.

The result is a simpler lens system and higher sensitivity, Kazuichiro Itonaga, a device manager with Sony's R&D Platform in Atsugi-shi, Japan reported on Tuesday at the Symposium on VLSI Technology in Honolulu, Hawaii.

A curved CMOS sensor has a few advantages over a planar sensor, Itonaga said. Because of the geometry, it can be paired with a flatter lens and a larger aperture, which lets in more light. Photodiodes at the periphery of a sensor array will be bent toward the center, which means light rays will hit them straight on instead of obliquely. What's more, the strain induced on a CMOS sensor by bending it alters the band gap of the silicon devices in the sensor region, lowering the noise created by "dark current" — the current that flows through a pixel even when it is receiving no external light. 

All told, the curved systems were 1.4 times more sensitive at the center of the sensor and twice as sensitive at the edge, according to the Sony engineers.

Itonaga gave few details on the process the team used to create the curved CMOS chips. He said that a machine was used to bend the CMOS sensors and that they were backed with a ceramic to stabilize them after bending. It was also unclear how much the chips were curved, although Itonaga said that they did achieve the same level of curvature found in the human eye.

Two chips were reported. One, which measured some 43 millimeters along the diagonal, is a full-size chip for digital cameras. The other is a smaller chip, more suitable for mobile phones, which measured 11 mm along the diagonal and boasts smaller pixels. The team integrated the curved image sensor with a lensing system and showed an image that seemed to be quite good, although it wasn't displayed alongside an image taken with an equivalent flat sensor for comparison.

This isn't the first curved image sensor to be developed. In 2008, for example, John Rogers' group at the University of Illinois at Urbana-Champaign reported they'd made a curved photodetector array by bending an array of photodiode islands connected by compressible interconnect. But Sony's work might be a bit closer to mass manufacture. The team has made somewhere in the vicinity of 100 full-size sensors with their bending machine. "We are ready," Itonaga said.

Nanotubes Capture Terahertz Radiation

A new type of detector for terahertz radiation, made from carbon nanotubes and requiring no power to operate, could usher in better airport scanners, new medical imagers, and more sensitive instruments for inspecting food and machine parts.

The detector is an array of carbon nanotubes made into a thin film 1 to 2 micrometers thick, grown on a layer of silicon. Previous attempts to use nanotubes as terahertz detectors proved difficult, because an individual nanotube had to be attached to a much larger antenna to collect the radiation. In this case, the terahertz photons are caught by a small but visible array, about 100 µm wide and roughly a millimeter long. Robert Hauge, a chemist at Rice University, in Houston, Tex., and Francois Leonard, of the Nanophotonics and Nanoelectronics Group at Sandia National Laboratory, in Livermore, Calif., and their colleagues describe the work in a recent paper in Nano Letters.

To make the array, researchers etched lines into the silicon and added iron/aluminum oxide catalysts. They then used chemical vapor deposition to grow aligned carbon nanotubes from those catalysts. The process naturally produces a mix of metallic and semiconducting nanotubes, with the overall array having an excess of positive charge. They then transferred the array onto a thermally conducting substrate—either aluminum nitride, Teflon, or a combination of the two. Next they attached gold electrodes to either end. Finally, they placed a drop of benzyl viologen onto half of the array, turning the treated nanotubes from positive to negative and creating a p-n junction.

When terahertz radiation strikes the p-n junction, it causes a photothermoelectric effect; the nanotubes heat up and cause a current to flow. The team can then measure the current to tally up the T-rays reaching the detector. Nanotubes absorb light strongly across a wide range of wavelengths, so they don’t have to apply a voltage to get a photocurrent. In fact, the scientists were able to measure light from green in the visible region to the far end of the terahertz region.

Leonard says researchers still need to integrate the detector with a source of T-rays, as well as with electronics to better measure the incoming signal. Sandia is mainly focused on security applications of terahertz radiation, he says; that frequency can penetrate most materials and return a spectrographic signature, making it easy to detect drugs and explosives, but unlike X-rays it doesn’t damage human tissue. But terahertz radiation could also be used for non-destructive testing, for instance checking the thickness of coatings on pharmaceuticals or examining the quality of paint on a machine’s embedded components.

HP's Water-Cooled Supercomputer is Designed for the Hydrophobic

Anybody who has spilled a beverage on a smart phone or laptop knows that water and computers don’t mix. But Hewlett Packard has designed a way to water-cool its servers with minimal risk of water leaking onto electrical components.

On Monday, HP introduced a supercomputer, called the Apollo 8000, which uses water-cooling to improve energy efficiency. Engineers have designed the system in a way that the active components are cooled directly by circulating water through server racks yet the water doesn’t enter into server enclosures.

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The Bike Helmet That Reads Your Brainwaves

"This is your brain on bike," said Arlene Ducao at a recent talk in New York City, showing off a map of city streets studded with colorful dots. Ducao is the inventors of MindRider, the bike helmet that reads its riders' brainwaves. The helmet also correlates the bikers' mental state with their geographical routes, creating maps of what Ducao calls the city's "psychogeography."

Sound neat? The Kickstarter campaign launched today. 

Ducao came up with the helmet idea while a student at the MIT Media Lab, and is now hoping to make it a real product. The helmet has a commercially available EEG sensor embedded in its foam, which is supposed to register the rider's mental state on a continuum of relaxed to focused concentration. A small LED light on the helmet indicates that mental state in real time (from green for relaxed to red for intense attention), and the information is also sent to the MindRider app on the user's phone.  

With the app, users can examine maps of their bike routes and potentially determine which streets are stressing them out. In the Kickstarter video below, one rider says the information gives him "insight into where we need better bike lanes." 

It remains to be seen if bike riders are eager to analyze their on-the-go neural activity. But this clever piece of hardware is part of a trend enabled by newly cheap and available brain monitoring systems. It seems likely that quantified selfers will soon have many opportunities to track not just their steps and heart rates, but also their brain patterns. 

Satellites Watch for Warnings of Volcano Eruptions

Volcanoes erupting like angry boils across the face of the Earth no longer need seem as mysterious as the unpredictable moods of the gods. Satellites flying 36,000 kilometers above the Earth's equator have proven they can take the temperature of volcanic lava as effectively as thermal cameras on the ground—a step toward making better predictions of future eruptions.

The new satellite measurement technique used the SEVIRI (Spinning Enhanced Visible and InfraRed Imager) instrument aboard a Meteosat satellite to monitor the temperature of a lava lake within Mount Nyiragongo, in the Democratic Republic of Congo. European researchers who pioneered the technique also used the same trick to study a lava fountain at Sicily's Mount Etna, in August 2011.

"We found a very similar radiant heat flux curve—that's the measurement of heat energy being given out—from the ground-based thermal camera placed a few kilometers from Etna and from SEVIRI at 36,000 kilometers above the Earth," said Gaetana Ganci, a researcher at the the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in Italy, in a press release.

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Virtual Tween Passes Turing Test

Eugene Goostman, a chatbot masquerading as a 13-year-old Ukrainian boy (with a notably short attention span), finally passed his exams. The program, whose development started in 2001—so he is really 13 years old—beat competitors by scoring 33 percent in Turing Test 2014, an event held at the Royal Society in London and organized by the University of Reading.

Eugene (or “Zhenya,” as he told one judge he likes to be called) thus became the first in that competition to meet the criteria of the “imitation game” for artificial intelligence, suggested by cybernetics pioneer Alan Turing in 1950. The test is simple: converse so naturally that human interlocutors think they are talking to another person.

Eugene Goostman started a-life in Saint Petersburg, as a project of Vladimir Veselov (whose LinkedIn page indicates that his day job is engineering software for Amazon), Eugene Demchenko, and Sergey Ulasen. According to Eugene’s Wikipedia page, he hails from Odessa, is the son of a gynecologist, and owns a pet guinea pig.

As impressive as the technology is, the developers’ ability to craft a backstory that makes the machine’s responses credible is the real key. Context is all.

“Our main idea,” said Veselov after the win, “was that he can claim that he knows anything, but his age also makes it perfectly reasonable that he doesn't know everything. We spent a lot of time developing a character with a believable personality. This year we improved the 'dialog controller' which makes the conversation far more human-like when compared to programs that just answer questions. Going forward we plan to make Eugene smarter and continue working on improving what we refer to as 'conversation logic.'"

The competition called for a judge to conduct a series of five-minute conversations in real time with two “people,” one of whom was carbon-based and the other, digital. Eugene Goostman persuaded 10 judges that he was the human participant in 33 percent of the 30 conversations in which he participated.  Each of the five competing AIs participated in 30 conversations.

The competition’s cut-off is 30 percent. Eugene Goostman hit 29 percent in Turing Test 2012, the previous competition. That was the top mark of the year, but not quite enough to be declared (almost) a real, live boy. This year’s 33-percent score was enough to pass.

The developers have reportedly made an instantiation of Eugene Goostman available online, but the surge in traffic following the Turing Test 2014 announcement seems to have crashed the server. And transcripts of this year’s Turing Test are not yet available. But Time writer Doug Aamoth published an interview with Eugene Goostman on 9 June. As Aamoth observes:

Passing the Turing Test is less about building machines intelligent enough to convince humans they’re real and more about building programs that can anticipate certain questions from humans in order to pre-form and return semi-intelligible answers.

In their opening exchange, Aamoth asks Eugene, “How are you adjusting to all your new-found fame?” To which Eugene replies,I would rather not talk about it if you don’t mind. By the way, what’s your occupation? I mean—could you tell me about your work?”

The Guardian published samples of Eugene’s conversations from Turing Test 2012. And those interested in a more detailed report of that test should take a look at a 2013 paper by the Turing Test director in IEEE Transactions on Computational Intelligence and AI in Games.

In both sets of exchanges, there are lapses of grammar, gaps in knowledge, and sudden changes of subject that might only be plausible in an early adolescent whose native language is not English, and who may have just a touch of attention deficit hyperactivity disorder. But the pattern will not seem totally alien to anybody who has had a tween child, taught in middle school, or, indeed, been a 13-year-old boy himself.

As The Guardian points out:

In 2011, at the Techniche festival in Guwahati, India, an application called Cleverbot took part in a Turing-type test and was perceived to be human by 59.3% of its interlocutors (compared with a score of 63.3% for the average human participant). However, because the program draws on a database of real conversations, many disputed whether it was in fact exhibiting true "intelligence."


Medtronic Wants to Implant Sensors in Everyone

Today, when doctors suspect that a patient has a cardiac arrhythmia that could lead to a heart attack, they can implant a tiny cardiac monitor smaller than a AAA battery in the patient's chest, directly over the heart. The company that makes that monitor, Medtronic, thinks the day will come when perfectly healthy people will be clamoring to have that gear inside them as well.

At a Medical Design & Manufacturing conference today, Medtronic program director Mark Phelps described his company's successful efforts to miniaturize its cardiac technologies. In February, the company began a clinical trial of its pill-sized pacemaker, which is implanted inside the heart. While Phelps presented that tiny pacemaker as a remarkable feat of engineering, he saved his real excitement for the tiny Linq cardiac monitor, which went on sale this year. Phelps declared that the device heralded "the beginning of a new industry" in diagnostic and monitoring implants.

Phelps argued that such an implant could be enhanced with more sensors to give people reams of biometric information, which would improve their healthcare throughout their lives. Young healthy people could use the sensors to track heart rate and calories burned, the kind of information that quantified selfers get today from wearable gadgets like the Fitbit. Later, the sensors would help with disease management, as they could be programmed to monitor particular organs or systems. Finally, they could enable independent living for the elderly by allowing doctors to keep watch over their patients remotely. "I would argue that it will eventually be seen as negligent not to have these sensors," Phelps said. "It's like driving without any gauges of your feedback systems."

The data generated by these implants would be provided to both the patient and the physician, Phelps said, and would allow both to see how lifestyle changes affect the patient's health over time, or how his or her body reacts to certain pharmaceuticals. This Big Data approach could enable a shift from reactive, symptom-based medicine to a preventative care model.

Such a medical system would be intrusive in two senses, Phelps admitted: Not only would doctors be physically cutting into a patient's body, they would also be exposing a great deal of the patient's biometric data. Yet Phelps believes that people will embrace the sensor-enabled lifestyle. "You'll get so used to having that feedback and information, you won't be able to imagine life without it," he said.

Report: NASA Needs Vision, “Horizon” to Get to Mars

Since the last Apollo moon mission in 1972, NASA has enjoyed many bold interplanetary success stories with unmanned programs like Voyager, Cassini, and the Mars rovers. However, the agency’s human spaceflight program during the same period—from Skylab, to the Space Shuttle, to the International Space Station—for all its successes, has remained firmly in low-earth orbit.

And if NASA and its partner agencies want to return astronauts to the surface of the Moon and perhaps ultimately to Mars, it needs both international cooperation and bold leadership, not just the careful, incremental vision its manned program has become known for in the post-Apollo era.

So says a new report commissioned by Congress and authored by the National Research Council (NRC).

After all, the study says, “no single rationale alone seems to justify the value of pursuing human spaceflight.” NASA needs to make a case that the report calls “inspirational and aspirational” that can bolster public support and enable the agency to weather any budgetary battles, economic downturns, technological setbacks or unfortunate accidents along the way.

When the report’s authors requested the public’s input on the future of human spaceflight, they received more than 200 white papers and 1600 original Tweets (#HumansInSpace).

The overriding theme of these comments, the report says, was emphasis of commercial partnerships — such as its existing ones with Orbital Services Corp and Space X, partnerships that are themselves the subject of a separate new agency report. The comments also pointed out the economic and technological benefits of international arrangements (especially with China) that could enable the entire world to participate in getting humans to Mars.

The report arrives at many similar conclusions. For instance, its authors argue, it is in the United States' best interests to seek international cooperation, in part because any actual manned mission to Mars would be so expensive that NASA would likely need to defray those costs with extensive international partnerships. And the report delicately but deliberately trains attention on the 2011 Congressional ban on any NASA collaborations with the Chinese space program. The ban, it says, “reduces substantially the potential international capability that might be pooled to reach Mars.”

And Mars, it says, is what the report calls a “horizon goal,” an overarching vision that is needed to jumpstart NASA’s human spaceflight program. Not since President Kennedy’s 1961 speech announcing what became the Apollo program has the agency had such a “horizon” goal. Mars, says the report, could be that next horizon. However, says the NRC report, human spaceflight “conducted by the U.S. government today has no strong direction and no firm timetable for accomplishments.”

Prickless Glucose Monitor That Uses Spit Takes Giant Step Forward

Researchers have developed a new biochip sensor that could enable diabetic patients to monitor their blood sugar levels without drawing any blood. The findings are based on a two-step process, the first part of which Spectrum blogged about in 2012.

The basic idea is to use the hypersensitive technique of interferometry to tease out and then quantify the presence of glucose molecules in a person’s saliva.

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Textbooks: The New Digital File Sharing Frontier

The music industry, which for years has been complaining about unauthorized copying and distribution of their intellectual property, now has company. Sharing their piracy misery are textbook publishers. An increasing number of book titles are showing up on peer-to-peer file sharing sites, as students, with Napster as a historical blueprint, copy then digitize hundreds of pages in order to make them available over the Web for free. What would motivate a college kid to stand at a photocopier for hours? Revenge. Many students feel that they're being fleeced by publishers who, aided and abetted by professors, force new and ever …

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