Graphene research may lead to electronics improvement

A fairly radical improvement. Try highly efficient, very-low-heat producing and smaller electronics devices. I enjoy blogging about nanotech research with real promise for market applications.

From the link:

NIST recently constructed the world’s most powerful and stable scanning-probe microscope, with an unprecedented combination of low temperature (as low as 10 millikelvin, or 10 thousandths of a degree above absolute zero), ultra-high vacuum and high magnetic field. In the first measurements made with this instrument, the team has used its power to resolve the finest differences in the electron energies in graphene, atom-by-atom.

“Going to this resolution allows you to see new physics,” said Young Jae Song, a postdoctoral researcher who helped develop the instrument at NIST and make these first measurements.

And the new physics the team saw raises a few more questions about how the electrons behave in graphene than it answers.

Because of the geometry and electromagnetic properties of graphene’s structure, an electron in any given energy level populates four possible sublevels, called a “quartet.” Theorists have predicted that this quartet of levels would split into different energies when immersed in a magnetic field, but until recently there had not been an instrument sensitive enough to resolve these differences.

“When we increased the magnetic field at extreme low temperatures, we observed unexpectedly complex quantum behavior of the electrons,” said NIST Fellow Joseph Stroscio.

What is happening, according to Stroscio, appears to be a “many-body effect” in which electrons interact strongly with one another in ways that affect their energy levels.

Cool nanotech image — the perfect nanocube

Check this out …

Caption: These electron microscope images show perfect-edged nanocubes produced in a one-step process created at NIST that allows careful control of the cubes’ size, shape and composition.

Credit: NIST

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Related news release: The perfect nanocube: Precise control of size, shape and composition

And:

Caption: These electron microscope images show perfect-edged nanocubes produced in a one-step process created at NIST that allows careful control of the cubes’ size, shape and composition.

Credit: NIST

Usage Restrictions: None

Related news release: The perfect nanocube: Precise control of size, shape and composition

Head below the fold for the accompanying release:

The world’s darkest material

I’ve previously blogged on a world’s darkest material in the past (couldn’t find the post in the archives, however) and it was nanotech-based as well so it’s possible this is the same stuff. Pretty cool either way.

From the link:

Harnessing darkness for practical use, researchers at the National Institute of Standards and Technology have developed a laser power detector coated with the world’s darkest material — a forest of carbon nanotubes that reflects almost no light across the visible and part of the infrared spectrum.

NIST will use the new ultra-dark detector, described in a new paper in Nano Letters,* to make precision laser power measurements for advanced technologies such as optical communications, laser-based manufacturing, solar energy conversion, and industrial and satellite-borne sensors.

Inspired by a 2008 paper by Rensselaer Polytechnic Institute (RPI) on “the darkest man-made material ever,”** the NIST team used a sparse array of fine nanotubes as a coating for a thermal detector, a device used to measure laser power. A co-author at Stony Brook University in New York grew the nanotube coating. The coating absorbs laser light and converts it to heat, which is registered in pyroelectric material (lithium tantalate in this case). The rise in temperature generates a current, which is measured to determine the power of the laser. The blacker the coating, the more efficiently it absorbs light instead of reflecting it, and the more accurate the measurements.

This is a colorized micrograph of the world’s darkest material — a sparse “forest” of fine carbon nanotubes — coating a NIST laser power detector. Image shows a region approximately 25 micrometers across. Credit: Aric Sanders, NIST

Separating and sizing nanoparticles

A useful nanotech development.

The release:

NIST nanofluidic ‘multi-tool’ separates and sizes nanoparticles

		IMAGE: A 3-D nanofluidic “staircase ” channel with many depths was used to separate and measure a mixture of different-sized fluorescent nanoparticles. Larger (brighter) and smaller (dimmer) particles were forced toward the… Click here for more information.

A wrench or a screwdriver of a single size is useful for some jobs, but for a more complicated project, you need a set of tools of different sizes. Following this guiding principle, researchers at the National Institute of Standards and Technology (NIST) have engineered a nanoscale fluidic device that functions as a miniature “multi-tool” for working with nanoparticles—objects whose dimensions are measured in nanometers, or billionths of a meter.

First introduced in March 2009 (see “NIST-Cornell Team Builds World’s First Nanofluidic Device with Complex 3-D Surfaces”, the device consists of a chamber with a cascading “staircase” of 30 nanofluidic channels ranging in depth from about 80 nanometers at the top to about 620 nanometers (slightly smaller than an average bacterium) at the bottom. Each of the many “steps” of the staircase provides another “tool” of a different size to manipulate nanoparticles in a method that is similar to how a coin sorter separates nickels, dimes and quarters.

In a new article in the journal Lab on a Chip*, the NIST research team demonstrates that the device can successfully perform the first of a planned suite of nanoscale tasks—separating and measuring a mixture of spherical nanoparticles of different sizes (ranging from about 80 to 250 nanometers in diameter) dispersed in a solution. The researchers used electrophoresis—the method of moving charged particles through a solution by forcing them forward with an applied electric field—to drive the nanoparticles from the deep end of the chamber across the device into the progressively shallower channels. The nanoparticles were labeled with fluorescent dye so that their movements could be tracked with a microscope.

As expected, the larger particles stopped when they reached the steps of the staircase with depths that matched their diameters of around 220 nanometers. The smaller particles moved on until they, too, were restricted from moving into shallower channels at depths of around 110 nanometers. Because the particles were visible as fluorescent points of light, the position in the chamber where each individual particle was stopped could be mapped to the corresponding channel depth. This allowed the researchers to measure the distribution of nanoparticle sizes and validate the usefulness of the device as both a separation tool and reference material. Integrated into a microchip, the device could enable the sorting of complex nanoparticle mixtures, without observation, for subsequent application. This approach could prove to be faster and more economical than conventional methods of nanoparticle sample preparation and characterization.

The NIST team plans to engineer nanofluidic devices optimized for different nanoparticle sorting applications. These devices could be fabricated with tailored resolution (by increasing or decreasing the step size of the channels), over a particular range of particle sizes (by increasing or decreasing the maximum and minimum channel depths), and for select materials (by conforming the surface chemistry of the channels to optimize interaction with a specific substance). The researchers are also interested in determining if their technique could be used to separate mixtures of nanoparticles with similar sizes but different shapes—for example, mixtures of tubes and spheres.

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* S.M. Stavis, J. Geist and M. Gaitan. Separation and metrology of nanoparticles by nanofluidic size exclusion. Lab on a Chip, forthcoming, August 2010

The latest supercomputer concept — atomtronic computers

This is a really wild idea, and truly once we are able to manipulate individual atoms in this way supercomputing will only be one of the amazing things that’ll be happening.

From the link:

“The emerging field of atomtronics aims to construct analogies of electronic components, systems and devices using ultracold atoms,” say Ron Pepino and pals at the National Institute of Standards and Technology (NIST) in Boulder Colorado.

Today, they outline their vision for atomtronics, show how it works and explain why it could shape the future of information processing.

The idea is to manipulate neutral atoms using lasers in a way that mimics the behaviour of electrons in wires, transistors and logic gates. Over the last decade or two, physicists at NIST and elsewhere have become masters at creating optical lattices in which atoms can be pushed pulled and prodded at will.

But this kind of optical lion taming has limited appeal so Pepino and co have begun a program to put tame atoms to work.

The problem is that atoms don’t behave like electrons so building the atomtronic equivalent of something even as straightforward as a simple circuit consisting of a battery and resistor in series, requires some thinking out of the box.

Pepino and co say that transferring atoms from one reservoir to another is a decent enough analogy and that this transfer can take place thorugh an optical lattice in which atoms tunnel at a uniform rate. That’s their simple circuit analogy.

Cool nanotech image — atomic moire pattern of graphene

Check this out:

Caption: Moiré patterns appear when two or more periodic grids are overlaid slightly askew, which creates a new larger periodic pattern. Researchers from NIST and Georgia Tech imaged and interpreted the moiré patterns created by overlaid sheets of graphene to determine how the lattices of the individual sheets were stacked in relation to one another and to find subtle strains in the regions of bulges or wrinkles in the sheets.

Credit: NIST

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Related news release: Seeing moire in graphene

Roadblock to effective transparent, current-carrying nanocoating

This is something of a setback in an exciting area of solar panel improvement.

The release:

NIST scientists address ‘wrinkles’ in transparent film development

		IMAGE: This atomic-force microscopy image shows wrinkling in a single-wall carbon nanotube membrane; the inset shows an optical reflection micrograph of the membrane without any strain. The random arrangement of the… Click here for more information.

A closer look at a promising nanotube coating that might one day improve solar cells has turned up a few unexpected wrinkles, according to new research* conducted at the National Institute of Standards and Technology (NIST) and North Dakota State University (NDSU)—research that also may help scientists iron out a solution.

The scientists have found that coatings made of single-walled carbon nanotubes (SWCNTs) are not quite as deformable as hoped, implying that they are not an easy answer to problems that other materials present. Though films made of nanotubes possess many desirable properties, the team’s findings reveal some issues that might need to be addressed before the full potential of these coatings is realized.

“The irony of these nanotube coatings is that they can change when they bend,” says Erik Hobbie, now the director of the Materials and Nanotechnology program at NDSU. “Under modest strains, these films can develop irreversible changes in nanotube arrangement that reduce their conductivity. Our work is the first to suggest this, and it opens up new approaches to engineering the films in ways that minimize these effects.”

High on the wish list of the solar power industry is a cheap, flexible, transparent coating that can conduct electricity. If this combination of properties can somehow be realized in a single material, solar cells might become far less expensive, and manufacturers might be able to put them in unexpected places—such as articles of clothing. Transparent conductive coatings can be made of indium-tin oxide, but their rigidity and high cost make them less practical for widespread use.

Carbon nanotubes are one possible solution. Nanotubes, which resemble microscopic rolls of chicken wire, are inexpensive, easy to produce, and can be formed en masse into transparent conductive coatings whose weblike inner structure makes them not only strong but deformable, like paper or fabric. However, the team’s research found that some kinds of stretching cause microscopic ‘wrinkles’ in the coating that disrupt the random arrangement of the nanotubes, which is what makes the coating conduct electricity.

“You want the nanotubes to stay randomly arranged,” Hobbie says. “But when a nanotube coating wrinkles, it can lose the connected network that gives it conductivity. Instead, the nanotubes bundle irreversibly into ropelike formations.”

Hobbie says the study suggests a few ways to address the problem, however. The films might be kept thin enough so the wrinkling might be avoided in the first place, or designers could engineer a second interpenetrating polymer network that would support the nanotube network, to keep it from changing too much in response to stress. “These approaches might allow us to make coatings of nanotubes that could withstand large strains while retaining the traits we want,” Hobbie says.

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* E. K. Hobbie, D. O. Simien, J. A. Fagan, J. Y. Huh, J. Y.Chung, S. D. Hudson, J. Obrzut, J. F. Douglas, and C. M. Stafford. Wrinkling and Strain Softening in Single-Wall Carbon Nanotube Membranes. Physical Review Letters, March 26, 2010, 104, 125505.

Graphene may be key to storing hydrogen

Needless to say this will have a major impact on using hydrogen as a power source in fuel cells or other applications.

The release:

Layered graphene sheets could solve hydrogen storage issues

		IMAGE: A graphene-oxide framework (GOF) is formed of layers of graphene connected by boron-carboxylic “pillars.” GOFs such as this one are just beginning to be explored as a potential storage medium… Click here for more information.

Graphene—carbon formed into sheets a single atom thick—now appears to be a promising base material for capturing hydrogen, according to recent research* at the National Institute of Standards and Technology (NIST) and the University of Pennsylvania. The findings suggest stacks of graphene layers could potentially store hydrogen safely for use in fuel cells and other applications.

Graphene has become something of a celebrity material in recent years due to its conductive, thermal and optical properties, which could make it useful in a range of sensors and semiconductor devices. The material does not store hydrogen well in its original form, according to a team of scientists studying it at the NIST Center for Neutron Research. But if oxidized graphene sheets are stacked atop one another like the decks of a multilevel parking lot, connected by molecules that both link the layers to one another and maintain space between them, the resulting graphene-oxide framework (GOF) can accumulate hydrogen in greater quantities.

Inspired to create GOFs by the metal-organic frameworks that are also under scrutiny for hydrogen storage, the team is just beginning to uncover the new structures’ properties. “No one else has ever made GOFs, to the best of our knowledge,” says NIST theorist Taner Yildirim. “What we have found so far, though, indicates GOFs can hold at least a hundred times more hydrogen molecules than ordinary graphene oxide does. The easy synthesis, low cost and non-toxicity of graphene make this material a promising candidate for gas storage applications.”

The GOFs can retain 1 percent of their weight in hydrogen at a temperature of 77 degrees Kelvin and ordinary atmospheric pressure—roughly comparable to the 1.2 percent that some well-studied metal-organic frameworks can hold, Yildirim says.

Another of the team’s potentially useful discoveries is the unusual relationship that GOFs exhibit between temperature and hydrogen absorption. In most storage materials, the lower the temperature, the more hydrogen uptake normally occurs. However, the team discovered that GOFs behave quite differently. Although a GOF can absorb hydrogen, it does not take in significant amounts at below 50 Kelvin (-223 degrees Celsius). Moreover, it does not release any hydrogen below this “blocking temperature”—suggesting that, with further research, GOFs might be used both to store hydrogen and to release it when it is needed, a fundamental requirement in fuel cell applications.

Some of the GOFs’ capabilities are due to the linking molecules themselves. The molecules the team used are all benzene-boronic acids that interact strongly with hydrogen in their own right. But by keeping several angstroms of space between the graphene layers—akin to the way pillars hold up a ceiling—they also increase the available surface area of each layer, giving it more spots for the hydrogen to latch on.

According to the team, GOFs will likely perform even better once the team explores their parameters in more detail. “We are going to try to optimize the performance of the GOFs and explore other linking molecules as well,” says Jacob Burress, also of NIST. “We want to explore the unusual temperature dependence of absorption kinetics, as well as whether they might be useful for capturing greenhouse gases such as carbon dioxide and toxins like ammonia.”

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The research is funded in part by the Department of Energy.

* J. Burress, J. Simmons, J. Ford and T.Yildirim. “Gas adsorption properties of graphene-oxide-frameworks and nanoporous benzene-boronic acid polymers.” To be presented at the March meeting of the American Physical Society (APS) in Portland, Ore., March 18, 2010. An abstract is available at http://meetings.aps.org/Meeting/MAR10/Event/122133

Want to see what the NIST has to say about national ID cards?

Check out this release.

(For the record I am extremely against the concept of any type of ID card, national or otherwise, that incorporates this level of personal data.  Quite hackable and doesn’t make the public any safer. These tracking devices only give the government that much more information on U.S. citizens.)

The release:

New NIST publications describe standards for identity credentials and authentication systems

Two publications from the National Institute of Standards and Technology (NIST) describe new capabilities for authentication systems using smart cards or other personal security devices within and outside federal government applications. A report describes a NIST-led international standard, ISO/IEC 24727, which defines a general-purpose identity application programming interface (API). The other is a draft publication on refinements to the Personal Identity Verification (PIV) specification.

NIST is responsible for developing specifications for PIV cards required for the government under Homeland Security Presidential Directive 12. These smart cards have embedded chips that hold information and biometric data such as specific types of patterns in fingerprints called “minutiae” along with a unique identifying number. The goal is to develop methods that allow each worker to have a PIV card that works with PIV equipment at all government agencies and with all card-reader equipment regardless of the manufacturer.

Because there is growing interest in using secure identity credentials like PIV cards for multiple applications beyond the federal workplace, NIST provided its smart card research expertise in the development of an international standard—ISO/IEC 24727 – Identification cards – Integrated circuit card programming interfaces—that provides a set of authentication protocols and services common to identity management frameworks.

The new NIST report, Use of ISO/IEC 24727 is an introduction to that standard. It describes the standard’s general-purpose identity application programming interface, the “Service Access Layer Interface for Identity (SALII)”, which allows cards and readers to communicate and operate with applications seamlessly. The report also describes a proof-of-concept experiment demonstrating that existing PIV cards and readers can work interoperably with ISO/IEC 24727. The applications tested included logging on to Windows or Linux systems, signing and encrypting email, and performing Web authentications.

NIST Interagency Report 7611 Use of ISO/IEC 24727 may be downloaded at http://csrc.nist.gov/publications/nistir/ir7611/nistir7611_use-of-isoiec24727.pdf.

NIST researchers also are involved in improving PIV components and providing guidelines that the private sector and municipalities can use with a similar smart ID card. They have drafted an update to an earlier publication that contains the technical specifications for interfacing with the PIV card to retrieve and use identity credentials.

Special Publication 800-73-3, Interfaces for Personal Identity Verification, provides specifications for PIV-Interoperable and PIV-Compatible cards issued by non-federal issuers, which may be used with the federal PIV system. It also provides specifications designed to ease implementation, facilitate interoperability and ensure performance of PIV applications in the federal workplace. The new publication specifies a PIV data model, card edge interface and application programming interface. The report also provides editorial changes to clarify information in the earlier version. (For background, see “Updated Specification Issued for PIV Card Implementations,” NIST Tech Beat, Oct. 14, 2008 [http://www.nist.gov/public_affairs/techbeat/tb2008_1014.htm].)

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The draft version of NIST SP 800-73-3 is open for public comment through Sept. 13, 2009. The document is available online athttp://csrc.nist.gov/publications/PubsDrafts.html#800-73-3. Comments should be addressed to PIV_comments@nist.gov with “Comments on Public Draft SP 800-73-3” in the subject line

Search and rescue robots

The release from today:

Rescue robot exercise brings together robots, developers, first responders

		IMAGE: Robots are being trained to map spaces using their sensors. This robot travels through a simulated “wooded area ” that has uneven terrain and randomly placed PVC pipes as “trees. ” It… Click here for more information.

The National Institute of Standards and Technology (NIST) held a rescue robot exercise in Texas last week in which about three dozen robots were tested by developers and first responders in order to develop a standard suite of performance tests to help evaluate candidate mechanical rescuers. This exercise was sponsored by the Department of Homeland Security’s Science and Technology Directorate to develop performance standards for robots for use in urban search and rescue missions.

Urban search and rescue robots assist first responders by performing such tasks as entering partially collapsed structures to search for living victims or to sniff out poisonous chemicals. NIST is developing robot standards for testing in cooperation with industry and government partners.

“It is challenging to develop the test standards as the robots are still evolving,” explained Elena Messina, acting chief of the Intelligent Systems Division, “because standards are usually set for products already in use. But it is critical for developers to be able to compare results, which is not possible without reproducible test environments. So, we have reproducible rough terrain that everyone can build in their labs, whereas you can’t reproduce a rubble pile. This way, developers in Japan can run tests, and people in Chicago can understand what the robot achieved.”

The event took place at Disaster City, Texas, a test facility run by the Texas Engineering Extension Service (TEEX). The facility offers an airstrip, lakes, train wrecks and rubble piles that can be arranged for many types of challenging tests.

Exercises included testing battery capacity by having robots perform figure eights on an undulating terrain and mobility tests in which robots ran through increasingly challenging exercises beginning with climbing steps and escalating to climbing ramps and then making it up steps with unequal gaps. A new mapping challenge introduced at this event tests how accurate a robot-generated map can be—the robot must traverse a simulated “wooded area” that has uneven terrain and PVC pipes for trees, and create a map using its sensors. Researchers came from across the globe to collect data to feed into their mapping algorithms. NIST researchers developing ultra-high-resolution three-dimensional sensors also participated.

Communications and manipulator tests were performed and discussed at the November exercise will be submitted to ASTM International as a potential rescue robot test standard.

 

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To see the robots in action, three videos can be viewed at the Disaster City TEEX Web site: www.teexblog.blogspot.com/.

Quantum images

From KurzweilAI.net:

Physicists Produce Quantum-Entangled Images

PhysOrg.com, June 25, 2008 Researchers from the National Institute of Standards and Technology (NIST) and the University of Maryland (UM) have produced “quantum images,” pairs of information-rich visual patterns whose features are entangled (linked by the laws of quantum physics). (NIST) Matching up both quantum images and subtracting their fluctuations, their noise is lower (so their information content potentially higher) than it is from any two classical images. In addition to promising better detection of faint objects and improved amplification and positioning of light beams, the researchers’ technique for producing quantum images may someday be useful for storing patterns of data in quantum computers and transmitting large amounts of highly secure encrypted information.   Read Original Article>>

NIST preps bridge to molecular electronics

From KurzweilAI.net:

NIST team proves bridge from conventional to molecular electronics possible

KurzweilAI.net, March 19, 2008Researchers at the National Institute of Standards and Technology (NIST) have set the stage for building an “evolutionary link” between the microelectronics of today (built from semiconductor compounds) and future generations of devices, made largely from complex organic molecules, by assembling the devices on the same kind of substrate used in conventional microchips. Side and top view of NIST molecular resistor The ability to use a silicon crystal substrate compatible with the industry-standard CMOS (complementary metal oxide semiconductor) manufacturing technology paves the way for hybrid CMOS-molecular device circuitry. This, in turn, is a necessary precursor to a “beyond CMOS” totally molecular technology. National Institute of Standards and Technology News Release