Researchers Build a Working Carbon Nanotube Computer

In a paper in the journal Nature on Wednesday, the researchers reported that they had successfully built a working computer — albeit an extremely simple one — entirely from transistors fashioned from carbon nanotubes. The nanotubes, which are cylinder-shaped molecules, have long held the promise of allowing smaller, faster and lower-powered computing, though they have proved difficult to work with.

The Stanford Robust Systems Group, however, has made significant progress in the last 18 months, advancing from building individual carbon nanotube transistors to simple electronic circuits made by interconnecting the transistors, and this week to a complete computer made from an ensemble of just 142 low-power transistors.

While Stanford’s prototype computer is assembled from transistors that are gargantuan by industry standards — one micron vs. 22 nanometers — it is what computer scientists refer to as a “Turing complete” machine, meaning that it is capable of performing any computation, given enough time.

“It can run two programs concurrently, a counting program and a sorting program,” said H. S. Philip Wong, a Stanford University electrical engineer, and one of the leaders of the group. “We’ve spent a tremendous amount of time on this; in fact we’ve spent two generations of students on this.”

The computer is based on a subset of 20 of the instructions used by the commercial MIPS microprocessor, which itself was designed by a group of Stanford researchers led by Stanford’s current president, John Hennessy, during the 1980s.

“I think this is a really nice piece of work,” said Supratik Guha, director of physical sciences at I.B.M.’s Thomas J. Watson Research Center. “It’s a rudimentary demonstration that carbon nanotubes can be used to build a universal computer, or a Turing-complete machine. This is not the most efficient computer, but that wasn’t the point. It’s one of the first steps.”

Because the factory processes that underlie the modern semiconductor industry require such painstaking precision, any new technology that the industry might use must be perfected more than three years before it can be considered for use in commercial production.

Carbon nanotubes have continued to excite the material science field because of their proliferating array of allotropes — different forms of the material — all with potential. Dr. Guha complimented the Stanford group for maintaining its focus on a single engineering advance.

Currently, semiconductor industry leaders can make integrated silicon circuits with a feature size of 22 nanometers, roughly 4,000 of which could be spread across the width of a human hair. With the arrival of a new generation of smaller transistors roughly every two years, the industry generally believes that silicon will be scaled down to a limit of 5-nanometer transistors sometime after 2020.

The constant shrinking of transistor size over the last half-century has been important because it has significantly lowered the cost of computing, making it possible to build ever more powerful computers that are faster and cheaper, and consume less power with each generation.

While Intel has been generally circumspect about what material technology it plans to turn to when silicon ceases to “scale” down to smaller transistor sizes, I.B.M. has been more vocal and optimistic about the potential for carbon nanotubes.

The company has recently succeeded in creating an inverter, a basic logic element used in electronic circuits, using two different types of carbon nanotube transistors, and plans to demonstrate the device at a technical meeting at the end of the year.

The researchers said that their advance was not a scientific breakthrough, but it was a significant demonstration of the ability to work with a material other than silicon with great precision.

They also stressed that their research project was entirely compatible with industry-standard manufacturing processes based on silicon. This suggests that in the future it will be possible to build hybrid chips using carbon nanotubes at particular locations, and thus extend the life of silicon in computing.

The researchers said they were proud of their tiny prototype.

“This is a general computer and we can do anything with it,” said Max Shulaker, a Stanford graduate student who is a leading member of the research group. “We could in principle run 64-bit Windows, but it would take millions of years.”

Bits Blog: Researchers Develop Flexible Metal for 3-D Printers

A group of researchers from North Carolina State University have developed a liquid metal material that could be used in 3-D printers and lead to flexible gadgets.

The technology is outlined in a paper published in the journal Advanced Materials, which describes the flexible metal as “stretchable” and explains that many tiny dots of this material could be placed together to create larger, bendable sheets of metal.

screenshot via North Carolina State University Small drops of metal could be connected together to create flexible electronics.

The metal, an alloy of gallium and indium, is liquid at room temperature. But when it is exposed to air the alloy can create a thin skin around its outer layer. Think of the way air bubbles look when floating on top of water.

Although flexible metal might sound futuristic enough, the paper also says that this metal can be “self-healing,” similar to animals that can regenerate limbs when they are sliced off.

“These stretchable wires can be completely severed with scissors and rapidly self-heal both mechanically and electrically,” the paper notes.

A video demonstrating how the technology works uses a syringe to produce tiny dots of the metal that connect with each other and collectively join together.

“The fact that they are liquid means you could surround them with another material like rubber to make metallic structures that you can stretch and deform,” Michael Dickey, an assistant professor of engineering at North Carolina State University, told New Scientist in an interview.

Mr. Dickey said that if the syringe was switched with a 3-D printing head, that would produce a 3-D printer that could print metal. There is at least one caveat though. The material’s cost, he said, is roughly 100 times that of 3-D printing plastic.

Bits Blog: Researchers Find 25 Countries Using Surveillance Software

Thor Swift for The New York Times Bill Marczak, left, and Morgan Marquis-Boire have been studying government use of surveillance software.

Last May, two security researchers volunteered to look at a few suspicious e-mails sent to some Bahraini activists. Almost one year later, the two have uncovered evidence that some 25 governments, many with questionable records on human rights, may be using off-the-shelf surveillance software to spy on their own citizens.

Morgan Marquis-Boire, a security researcher at Citizen Lab, at the University of Toronto’s Munk School of Global Affairs, and Bill Marczak, a computer science doctoral student at the University of California, Berkeley, found that the e-mails contained surveillance software that could grab images off computer screens, record Skype chats, turn on cameras and microphones and log keystrokes. The word “FinSpy” appeared in the spyware code. FinSpy is spyware sold by the Gamma Group, a British company that says it sells monitoring software to governments solely for criminal investigations.

Now, one year later, Mr. Marquis-Boire and Mr. Marczak have found evidence that FinSpy is being run off servers in 25 countries, including Ethiopia and Serbia, without oversight.

Until Mr. Marquis-Boire and Mr. Marczak stumbled upon FinSpy last May, security researchers had tried, unsuccessfully, for a year to track it down. FinSpy gained notoriety in March 2011 after protesters raided Egypt’s state security headquarters and discovered a document that appeared to be a proposal by the Gamma Group to sell FinSpy to the government of President Hosni Mubarak .

Martin J. Muench, a Gamma Group managing director, has said his company does not disclose its customers but that Gamma Group sold its technology to governments only to monitor criminals. He said that it was most frequently used “against pedophiles, terrorists, organized crime, kidnapping and human trafficking.”

But evidence suggests the software is being sold to governments where the potential for abuse is high. “If you look at the list of countries that Gamma is selling to, many do not have a robust rule of law,” Mr. Marquis-Boire said. “Rather than catching kidnappers and drug dealers, it looks more likely that it is being used for politically motivated surveillance.”

As of last year, Mr. Marquis-Boire and Mr. Marczak, with other researchers at Rapid7, CrowdStrike and others, had found command-and-control servers running the spyware in just over a dozen countries. They have since scanned the entire Internet for FinSpy.

The Munk School is publishing their updated findings on Wednesday. The list of countries with servers running FinSpy is now Australia, Bahrain, Bangladesh, Britain, Brunei, Canada, the Czech Republic, Estonia, Ethiopia, Germany, India, Indonesia, Japan, Latvia, Malaysia, Mexico, Mongolia, Netherlands, Qatar, Serbia, Singapore, Turkmenistan, the United Arab Emirates, the United States and Vietnam.

In Ethiopia, FinSpy was disguised in e-mails that were specifically aimed at political dissidents. The e-mails lured targets to click on pictures of members of Ginbot 7, an Ethiopian opposition group. When they clicked on the pictures, FinSpy downloaded to their machines and their computers began communicating with a local server in Ethiopia.

“This continues the theme of FinSpy deployments with strong indications of politically motivated targeting,” the researchers wrote in their report.

A Turkmenistan server running the software belonged to a range of I.P. addresses specifically assigned to the ministry of communications. Turkmenistan is the first clear-cut case of a government running the spyware off its own computer system. Human Rights Watch has called Turkmenistan one of the world’s “most repressive countries” and warned that dissidents faced “constant threat of government reprisal.”

In Vietnam, the researchers found evidence that FinSpy was running on Android-powered phones. They found one Android phone infected with FinSpy that was sending text messages back to a Vietnamese telephone number. That finding was particularly troubling, researchers say, given recent clampdowns by the nation’s government. Last year, Vietnam introduced censorship laws that prohibit bloggers from speaking out against the country’s ruling Communist party. According to Human Rights Watch, at least 40 people had since been convicted and sentenced to prison terms. Many are now serving terms ranging from three to 13 years.

The sale of surveillance technology is still largely unregulated, but Mr. Marquis-Boire and Mr. Marczak’s findings have prompted greater scrutiny. Responding to their findings last fall, Germany’s foreign minister Guido Westerwelle called for an Europe-­wide ban on the export of surveillance technology to repressive regimes. And last month, Privacy International and other groups filed complaints with the Organization for Economic Cooperation and Development against Gamma Group and Trovicor GmbH, a German company that also sells surveillance software.

“I don’t think you can put technology back in the bottle,” said Mr. Marquis-Boire. “I understand why police would want to use this type of technology, but I’m just not for commercial companies selling them to nondemocratic regimes with questionable human rights records.”

Duke Researchers Develop a New Way to Compress Images

Using a new class of artificial materials, scientists at Duke University have designed a sensor that compresses images far more efficiently than existing technologies like JPEG.

The materials, called metamaterials, have exotic qualities that bend light, X-rays and radio waves in unusual ways.

While they are barely a decade old, they are fast falling in cost and are expected to become commercially available beginning within two years for a wide array of applications, including radio communications, security and automotive safety.

In 2006, the Duke researchers made headlines by demonstrating that an “invisibility cloak” could be created by bending the light that strikes a metamaterial.

The researchers, at the Center for Metamaterials and Integrated Plasmonics, reported Thursday in the journal Science that their scanning sensor captures both still and video images while simplifying compression by integrating it directly into the sensor array.

A cost advantage of the new technology is that it permits image compression to be performed directly by the sensor hardware, rather than by the specialized hardware and software in use today.

Although the cost of optical sensors has fallen rapidly, automobile manufacturers have been searching for alternatives to expensive laser radar, or Lidar, to provide sensors that work in a range of natural light conditions, including night, dust clouds and snowstorms.

The current generation of airport millimeter-wave security scanners has gained popularity because they do not rely on X-ray radiation and its attendant health risks.

But they require an elaborate mechanical arm that sweeps around a passenger standing in a scanning booth.

“The drawbacks are that it takes time and adds a lot of expense because of complicated mechanical rotors,” said the lead author of the Science paper, John Hunt, a graduate researcher at the Duke center. “We have been trying to replace the whole system with one that has no moving parts.”

Although the design of metamaterial sensors might offer high compression ratios, Mr. Hunt said the real advantage lay in the potential for reductions in size. For example, he noted, even the most advanced planes and boats today use a mechanically steered dish antenna for radar. This requires setting aside a large space to swivel the dish.

“Our system could potentially replace that with a flat sheet wrapped onto the side of the fuselage,” he said.

Another potential advantage is speed. Intellectual Ventures, established by the former Microsoft chief scientist Nathan Myhrvold, has started a company to develop communications antennas made from metamaterials.

The company, Kymeta, has said it will introduce an inexpensive high-speed satellite antenna as soon as the end of next year. Bill Gates, the Microsoft co-founder, is an investor.

Depending on the wavelength they are focused on, metamaterials are made with either printed circuit boards or semiconductors. The sensor elements can be laid out in a linear array or as a three-dimensional matrix.

If the elements are small enough, the materials can manipulate visible light; other researchers are exploring applications with both sound waves and seismic waves.

Metamaterials bend radiation more sharply than natural materials. One of their strangest qualities is the ability to create a structure with what scientists call a “negative refractive index” — a behavior of light and other forms of radiation that is not found when light waves pass through materials like glass or water. They can be aimed in many different directions, or used in parallel to increase bandwidth.