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Tech Beat - August 16, 2011

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Editor: Michael Baum
Date created: August 16, 2011
Date Modified: August 16, 2011 
Contact: inquiries@nist.gov

NIST Tests Help Ensure Reliable Wireless Alarm Beacons for First Responders

Wireless emergency safety equipment could save lives—if signals are transmitted reliably. But few performance standards exist. Now, tests at the National Institute of Standards and Technology (NIST) are helping to ensure that alarm beacons for firefighters and other emergency responders will operate reliably in the presence of other wireless devices.

Kate Remley
NIST engineer Kate Remley holds two Personal Alert Safety System (PASS) devices with wireless alarm capability.
Copyright: Paul Trantow/Altitude Arts
View hi-resolution image

NIST is providing technical support for industry consensus standards by developing test methods to evaluate how well these devices work under realistic conditions. The latest NIST study focused on interference between Personal Alert Safety Systems (PASS) with wireless alarm capability, and radio-frequency identification (RFID) systems. The methods developed in the study can test interference in other wireless devices such as radios, hands-free cell phone headsets, local area networks, and urban search and rescue robots.

PASS devices sense movement and activate an alarm if a firefighter remains motionless for too long. Newer PASS systems also have a wireless link connecting incident command base stations and portable units, allowing emergency recall signals to be sent to firefighters or “firefighter down” alarms to be sent to the base. Because firefighters also may carry RFID tags for location tracking, or may be in warehouses or other buildings using RFID inventory systems, there is potential for significant interference.

“Every wireless device will fail given strong enough interference,” says NIST project leader Kate Remley. “The question is the level at which the device fails. Our goal is to develop lab-based test methods to quantify the level of interference at which PASS units fail so we can help ensure they operate reliably.”

The NIST research, to be presented at a conference this week,* measured interference between “frequency hopping” PASS and RFID systems operating in similar frequency bands. Results show that, when signals are weak due to environmental or other conditions, a portable PASS unit’s receipt of an alarm from its base station can be delayed or fail even without interference, and becomes more likely to fail in the presence of only moderate RFID interference. Strong interference caused longer and variable delays that sometimes exceeded a minute, defined by the researchers as signal failure. NIST researchers also found that an RFID system can be less reliable when the PASS unit is nearby.

The NIST tests involved measuring the total output power of each system in a test chamber and then isolating the systems in different labs for the interference tests. The portable PASS device and RFID tag and reader were placed in a test chamber, while the PASS base station was in a separate room. Researchers evaluated performance at various levels of signal strength and interference.

NIST is working with the National Fire Protection Association, which will consider adopting the NIST tests as part of revised PASS performance standards. An NFPA technical committee on electronic safety equipment will soon consider the wording of a draft standard, and after a public comment period, the standards could be approved by 2013. At that point, manufacturers would need to show that their PASS devices pass the tests.

The research is supported by the Department of Homeland Security.

* K. Remley, M. Souryal, W.F. Young, D. Kuester, D. Novotny and J.R. Guerrieri. Interference tests for 900 MHz frequency-hopping public-safety wireless devices. Presented at the 2011 IEEE Electromagnetic Compatibility Symposium, Long Beach, Calif., Aug. 17, 2011.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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Kinder, Gentler Cell Capture Method Could Aid Medical Research

A research team at the National Institute of Standards and Technology (NIST) has come up with a potential solution to a two-pronged problem in medical research: How to capture cells on a particular spot on a surface using electric fields and keep them alive long enough to run experiments on them.

(A) As cells flow down the channel, they pass over the electrodes (vertical dark gray lines) until (B) the electrodes are activated and the cells are trapped and anchored. (C) The cells remain adhered even while being exposed continuously to a fluid flow. Scale bar 50 micrometers.
Credit: NIST
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Their method, which involves innovations upon conventional cell-capture techniques, has already proved effective in creating arrays of human liver cells and mouse pluripotent cells—which, similar to stem cells, can develop into more than one cell type.

"The technique could prove valuable for learning about how cells communicate and differentiate," says NIST chemist Darwin Reyes. "We think this method could provide an effective way to selectively induce cells to differentiate and watch their behavior as they develop."

Adherent cells need to be attached to a surface to survive, and one common way of getting them there is by using a technique called dielectrophoresis (DEP), which Reyes says is not necessarily the best for cells' health. A batch of cells is placed into a fluid medium that has low electrical conductivity—sucrose in water, for example—and then subjected to an electric field that attracts the cells to a nearby surface. But the DEP process requires the cells to spend between 20 and 30 minutes in the medium, which appears to cause problems when the cells are trying to attach to the surface.

"Cells typically die rather soon after that much time exposed to the sucrose, since they cannot attach to the surface," Reyes says. "It's tough to run useful experiments if you only have a short window of opportunity."

The team experimented with different materials before finding that they could use a layer of substance called polyelectrolyte that has its own positive electric charge, which attracts the cells quickly. Before depositing this material, they laid down a thin layer of natural protein called fibronectin that helps cells to survive once they stick. With this new hybrid surface, the cells need spend only about four minutes in the fluid before they are returned to a more nurturing medium that helps them grow and attach better. As a result, the cells can survive on the surface for a week or more.

Because of their success in creating arrays of neural cells, the team has recently started to pattern liver cells as well. Combining liver cells with this technique could be useful in toxicology studies, Reyes suggests. "The liver is made up of several types of cells that work together," he says. "Creating arrays of them with certain cells positioned in particular locations could help us study how each of them might contribute to the overall process of filtering out a toxin from the bloodstream."

* D.R. Reyes, J.S. Hong, J.T. Elliott and M. Gaitan. Hybrid cell adhesive material for instant dielectrophoretic cell trapping and long-term cell function assessment. Langmuir, 2011, 27, 10027-10034, DOI: 10.1021/la200762j.

Media Contact: Chad Boutin, boutin@nist.gov, 301-975-4261

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NIST Uncovers Reliability Issues for Carbon Nanotubes in Future Electronics

Carbon nanotubes offer big promise in a small package. For instance, these tiny cylinders of carbon molecules theoretically can carry 1,000 times more electric current than a metal conductor of the same size. It's easy to imagine carbon nanotubes replacing copper wiring in future nanoscale electronics.

gold electrodes
Micrograph of recession and clumping in gold electrodes after NIST researchers applied 1.7 volts of electricity to the carbon nanotube wiring for an hour. The NIST reliability tests may help determine whether nanotubes can replace copper wiring in next-generation electronics.
Credit: M. Strus/NIST
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But—not so fast. Recent tests at the National Institute of Standards and Technology (NIST) suggest device reliability is a major issue.

Copper wires transport power and other signals among all the parts of integrated circuits; even one failed conductor can cause chip failure. As a rough comparison, NIST researchers fabricated and tested numerous nanotube interconnects between metal electrodes. NIST test results, described at a conference this week,* show that nanotubes can sustain extremely high current densities (tens to hundreds of times larger than that in a typical semiconductor circuit) for several hours but slowly degrade under constant current. Of greater concern, the metal electrodes fail—the edges recede and clump—when currents rise above a certain threshold. The circuits failed in about 40 hours.

While many researchers around the world are studying nanotube fabrication and properties, the NIST work offers an early look at how these materials may behave in real electronic devices over the long term. To support industrial applications of these novel materials, NIST is developing measurement and test techniques and studying a variety of nanotube structures, zeroing in on what happens at the intersections of nanotubes and metals and between different nanotubes. "The common link is that we really need to study the interfaces," says Mark Strus, a NIST postdoctoral researcher.

In another, related study published recently,** NIST researchers identified failures in carbon nanotube networks—materials in which electrons physically hop from tube to tube. Failures in this case seemed to occur between nanotubes, the point of highest resistance, Strus says. By monitoring the starting resistance and initial stages of material degradation, researchers could predict whether resistance would degrade gradually—allowing operational limits to be set—or in a sporadic, unpredictable way that would undermine device performance. NIST developed electrical stress tests that link initial resistance to degradation rate, predictability of failure and total device lifetime. The test can be used to screen for proper fabrication and reliability of nanotube networks.

Despite the reliability concerns, Strus imagines that carbon nanotube networks may ultimately be very useful for some electronic applications. "For instance, carbon nanotube networks may not be the replacement for copper in logic or memory devices, but they may turn out to be interconnects for flexible electronic displays or photovoltaics," Strus says.

Overall, the NIST research will help qualify nanotube materials for next-generation electronics, and help process developers determine how well a structure may tolerate high electric current and adjust processing accordingly to optimize both performance and reliability.

* M.C. Strus, R.R. Keller and N. Barbosa III. Electrical reliability and breakdown mechanisms in single-walled carbon nanotubes. Paper presented at IEEE Nano 2011, Portland, Ore., Aug. 17, 2011.
** M.C. Strus, A.N. Chiaramonti, Y.L. Kim, Y.J. Jung and R.R. Keller. Accelerated reliability testing of highly aligned single-walled carbon nanotube networks subjected to dc electrical stressing. Nanotechnology 22 pp. 265713 (2011).

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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NIST Demonstrates First Quantum 'Entanglement' of Ions Using Microwaves

Physicists at the National Institute of Standards and Technology (NIST) have, for the first time, linked the quantum properties of two separated ions (electrically charged atoms) by manipulating them with microwaves instead of the usual laser beams. The feat raises the possibility of replacing today's complex, room-sized quantum computing "laser parks" with miniaturized, commercial microwave technology similar to that used in smart phones.

gold ion trap
Gold ion trap on aluminum nitride backing. In NIST microwave quantum computing experiments, two ions hover above the middle of the square gold trap, which measures 7.4 millimeters on a side. Scientists manipulate and entangle the ions using microwaves fed into wires on the trap from the three thick electrodes at the lower right.
Credit: Y. Colombe/NIST
View hi-resolution bottom image

Microwaves have been used in past experiments to manipulate single ions, but the NIST group is the first to position microwaves sources close enough to the ions—just 30 micrometers away—and create the conditions enabling entanglement, a quantum phenomenon expected to be crucial for transporting information and correcting errors in quantum computers.

Described in the August 11, 2011, issue of Nature,* the experiments integrate wiring for microwave sources directly on a chip-sized ion trap and use a desktop-scale table of lasers, mirrors and lenses that is only about one-tenth of the size previously required. Low-power ultraviolet lasers still are needed to cool the ions and observe experimental results but might eventually be made as small as those in portable DVD players. Compared to complex, expensive laser sources, microwave components could be expanded and upgraded more easily to build practical systems of thousands of ions for quantum computing and simulations.

"It's conceivable a modest-sized quantum computer could eventually look like a smart phone combined with a laser pointer-like device, while sophisticated machines might have an overall footprint comparable to a regular desktop PC," says NIST physicist Dietrich Leibfried, a co-author of the new paper.

Quantum computers would harness the unusual rules of quantum physics to solve certain problems—such as breaking today's most widely used data encryption codes—that are currently intractable even with supercomputers. A nearer-term goal is to design quantum simulations of important scientific problems, to explore quantum mysteries such as high-temperature superconductivity, the disappearance of electrical resistance in certain materials when sufficiently chilled.

Ions are a leading candidate for use as quantum bits (qubits) to hold information in a quantum computer. Although other promising candidates for qubits—notably superconducting circuits, or "artificial atoms"—are manipulated on chips with microwaves, ion qubits are at a more advanced stage experimentally in that more ions can be controlled with better accuracy and less loss of information.

The use of microwaves reduces errors introduced by instabilities in laser beam pointing and power as well as laser-induced spontaneous emissions by the ions. However, microwave operations need to be improved to enable practical quantum computations or simulations. The NIST researchers achieved entanglement 76 percent of the time, well above the minimum threshold of 50 percent defining the onset of quantum properties but not yet competitive with the best laser-controlled operations at 99.3 percent.

The research was supported by the Intelligence Advanced Research Projects Activity, Office of Naval Research, Defense Advanced Research Projects Agency, National Security Agency and Sandia National Laboratories.

For more details, see the NIST Aug. 11 news announcement "NIST Physicists 'Entangle' Two Atoms Using Microwaves for the First Time" at www.nist.gov/pml/div688/microwave-quantum-081011.cfm.

* C. Ospelkaus, U. Warring, Y. Colombe, K.R. Brown, J.M. Amini, D. Leibfried and D.J. Wineland. Microwave quantum logic gates for trapped ions. Nature. Aug. 11, 2011.

Media Contact: Laura Ost, laura.ost@nist.gov, 303-497-4880

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New Website Offers Easy Access to NIST Disaster and Failure Study Data

For more than 40 years, scientists and engineers at the National Institute of Standards and Technology (NIST) have studied structural failures caused by natural disasters, fires and man-made factors, and used the lessons learned to improve building and fire codes, standards and practices. With the launch of the Disaster and Failure Studies Data Repository, NIST has begun to make this valuable information accessible more easily online.

World Trade Center complex
Example of the photos that may be viewed on the new NIST Disaster and Failure Events Data Repository shows a worker from the Federal Emergency Management Agency (FEMA) at New York City’s World Trade Center complex a few days after the Sept. 11, 2001, terrorist attacks.
Credit: FEMA

The repository will ensure that data collected during and after a disaster or failure event, as well as data generated from related research, is organized and maintained to enable study, analysis and comparison with future severe disaster events. It also will serve as a national archival database where other organizations can store the research, findings and outcomes of their disaster and failure studies.

As the database grows, it will include data on significant hazard events; how buildings and other structures performed during those events; associated emergency response and evacuation procedures; and the technical, social and economic factors that affect pre-disaster mitigation activities and post-disaster response efforts.

The Disaster and Failure Studies Data Repository is being established in two phases:

Phase 1—which has just been completed—includes data from NIST’s six-year investigation of the collapses of three buildings at New York City’s World Trade Center (WTC 1, 2 and 7) as a result of the terrorist attacks on Sept. 11, 2001. Now available are thousands of photos and videos collected during the investigation; computer simulations created to model aircraft impact damage, fire spread and structural design characteristics; and the complete set of technical reports that document the body of NIST’s work.

Phase 2 will include a larger collection of information on hazard events such as earthquakes, hurricanes, tornadoes, windstorms, community-scale fires in the wildland-urban interface, structural fires, storm surges, floods and tsunamis, and man-made hazards (accidental, criminal or terrorist).

By making this data available online, NIST hopes to support the development of standards and new technologies that enable more efficient collection of data on disaster and failure events.

NIST is providing these materials as a public service and to comply with regulations that require federal agencies to provide equal access to data available for public release. The materials in the new online repository serve as a historical archive. Some of these materials may contain offensive language or images/videos that some may find graphic. Some of the materials are protected by copyrights owned by private individuals or organizations, and subject to restrictions. Where possible, NIST has identified the copyright owner.

The Disaster and Failure Studies Data Repository is accessible at http://www.nist.gov/el/disasterstudies/repository_home.cfm.



Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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Greenhouse Gases: The Measurement Challenge

The continuing increase in the level of carbon dioxide and other "greenhouse gases" in the Earth's atmosphere has been identified as a cause for serious concern because it may radically accelerate changes in the Earth's climate. Developing an effective strategy for managing the planet's greenhouse gases is complicated by the many and varied sources of such gases, some natural, some man-made, as well as the mechanisms that capture and "sequester" the gases. A new report sponsored by the National Institute of Standards and Technology (NIST) focuses on one of the key challenges: defining and developing the technology needed to better quantify greenhouse gas emissions.

The new report, "Advancing Technologies and Strategies for Greenhouse Gas Emissions Quantification," is the result of a special workshop in the NIST Foundations for Innovation series, convened in June 2010, to bring together greenhouse gas experts from government, industry, academia and the scientific community to address the technology and measurement science challenges in monitoring greenhouse gases.

A wide variety of techniques are used for measuring greenhouse gas emissions and, to a lesser extent, the effectiveness of "sinks"—things like the ocean and forests that absorb greenhouse gases and sequester the carbon. The problem is that developing an effective global strategy for managing greenhouse gases requires a breadth of measurement technologies and standards covering not only complex chemical and physical phenomena, but also huge differences in scale. These range from point sources at electric power plants to distributed sources, such as large agricultural and ranching concerns, to large-scale sinks such as forests and seas. Satellite-based systems, useful for atmospheric monitoring, must be reconciled with ground-based measurements. Reliable, accepted international standards are necessary so governments can compare data with confidence, requiring a lot of individual links to forge an open and verifiable chain of measurement results accepted by all.

The report identifies and discusses, in detail, four broad areas of opportunity for technology development and improvement:

  • Advanced science and technology for reliably quantifying greenhouse gas emissions, regardless of geography, sector or source;
  • Accurate and reliable quantification of distributed carbon sources and sinks;
  • Consistent, standardized methods for measurable, reportable and verifiable greenhouse gas emissions data; and
  • Integration of ground-based (bottom-up) and remote atmospheric observation (top-down) methods.

Copies of the new report are available at the Website for the 2010 June meeting, "Greenhouse Gas Emissions Quantification and Verification Strategies Workshop" at http://events.energetics.com/NISTScripps2010/downloads.html, along with additional materials from the workshop.

Media Contact: Michael Baum, baum@nist.gov, 301-975-2763

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NIST Awards $2.7 Million to 18 U.S. Small Business Research Projects

The National Institute of Standards and Technology (NIST) has announced nearly $2.7 million in Phase 1 and Phase 2 Small Business Innovation Research (SBIR) awards to 18 U.S. small businesses.

The awards provide funding to small businesses to help develop technologies that could lead to commercial and public benefit. Winning projects include a research platform for developing microscopic robots less than a millimeter in size, an environmental chamber for testing the weathering of materials, and an improved system for broadcasting time-of-day signals.

NIST's SBIR program is a competitive funding opportunity that provides contracts to small businesses for federal research and development. The program stimulates technological innovation in the private sector, strengthens the role of small business in meeting federal research and development needs, increases private-sector commercialization of federal research and development, and fosters technological innovation at minority and disadvantaged firms.

SBIR awards are funded through a three-phase process. In Phase 1, small businesses can receive up to $90,000 to establish the scientific or technical merit, or feasibility of ideas, that support the commercial potential of their research. Every year, NIST issues a "call for proposals" under Phase 1 of the SBIR program to address specific problems related to the agency's mission. Successful completion of Phase 1 enables awardees to compete for Phase 2 funding of up to $300,000 that enables them to continue their research and development efforts. Phase 1 awardees have six months to complete their work; Phase 2 awardees have up to two years. Phase 3 involves commercial applications of the newly developed technologies, with funding from outside of the SBIR program.

NIST solicits proposals for the SBIR program that fall within its mission and that, whenever possible, allow collaboration between NIST scientists and SBIR awardees. The SBIR program was established by Congress in 1982 under the Small Business Innovation Development Act.

A full list of the 18 awards is available online at www.nist.gov/public_affairs/releases/sbir-081011.cfm.

Media Contact: Mark Esser, mark.esser@nist.gov, 301-975-8735

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NIST Seeks Comments on National Initiative for Cybersecurity Education Draft Strategic Plan

The National Institute of Standards and Technology (NIST) today* issued for public comment a draft strategic plan for the National Initiative for Cybersecurity Education (NICE) program. The plan, "Building a Digital Nation," outlines NICE's mission, vision, goals and objectives. NIST and its interagency NICE partners seek comments from all interested citizens and organizations concerned with cybersecurity awareness, training and education.

NIST coordinates the interagency NICE program, which is a national campaign focused on enhancing cybersecurity in the United States by accelerating the availability of educational and training resources designed to improve the cyber behavior, skills and knowledge of every segment of the population. The program aims to improve secure use and access to digital information in a way that advances America's economic prosperity and national security.

"This plan represents the coordinated thinking of the federal agencies that have leading roles in NICE," said NIST's Ernest McDuffie, who leads the NICE program. "We are soliciting feedback from the larger population to inform and improve the planning process for this comprehensive national initiative."

Comments on the NICE draft strategic plan are due by September 12, 2011. NIST's federal partners that contributed to the plan include the Department of Homeland Security, the Department of Defense, the Department of Education, the National Science Foundation, the Office of Personnel Management and the National Security Agency.

The second annual NICE workshop, "Shaping the Future of Cybersecurity Education—Engaging Americans in Securing Cyberspace," will be held Sept. 20-22, 2011 at the NIST campus in Gaithersburg, Md., and will include discussion of the strategic plan. Government, academia and industry, as well as professionals from small- and medium-sized businesses are expected to be represented at the workshop.

To read the National Initiative for Cybersecurity Education strategic plan, visit http://go.usa.gov/KFv. Comments should be entered into the Comment-Template_Draft-NICE.xls, available at http://go.usa.gov/KFw, and e-mailed to nicestratplan@nist.gov.

* Originally published on Aug. 11, 2011.

Media Contact: Evelyn Brown, evelyn.brown@nist.gov, (301) 975 5661

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May Named as NIST's Associate Director for Laboratory Programs

Willie E. May, a 40-year veteran of the National Institute of Standards and Technology (NIST) has been named to serve as the agency’s Associate Director for Laboratory Programs. In his new position, May oversees and guides the management, operation and direction of NIST's six laboratory programs and is the principal deputy to the NIST Director.

Dr. Willie E. May, Director
Dr. Willie E. May, NIST Associate Director for Laboratory Programs
Credit: NIST

NIST's six laboratories include the Physical Measurement Laboratory, Material Measurement Laboratory, Engineering Laboratory, Information Technology Laboratory, the Center for Nanoscale Science and Technology and the NIST Center for Neutron Research. The NIST Laboratories collaborate with U.S. industry and universities to conduct measurement, standards and technology research that advances the nation's R&D infrastructure. The overarching goal of the NIST laboratory programs is to accelerate U.S. innovation, which is a major driver of economic growth and job creation.

Prior to his current position, May served as director of the Material Measurement Laboratory, which serves as the nation's reference laboratory for measurements in the chemical, biological and materials sciences. Before that, May led NIST's research and measurement service programs in chemistry-related areas for more than 20 years.

May holds several leadership positions outside of NIST, including: serving as vice president of the 18-person International Committee on Weights and Measures (CIPM) and chairing the CIPM Consultative Committee on Metrology in Chemistry's Organic Analysis Working Group; co-chairing the Joint Committee on Traceability in Laboratory Medicine's Working Group on Reference Materials and Reference Procedures; chairing the Executive Board for the Hollings Marine Laboratory in Charleston, S.C.; and sitting on the Board of Visitors for the University of Maryland–College Park's College of Computer, Mathematical, and Natural Sciences.

Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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May, Locascio Honored as ACS Fellows

Two distinguished scientists at the National Institute of Standards and Technology (NIST) Willie E. May and Laurie E. Locascio, have been named fellows of the American Chemical Society (ACS), the world’s largest scientific society and a global leader in providing access to chemistry-related research. May is NIST’s Associate Director for Laboratory Programs and former director of the agency’s Materials Measurement Laboratory (MML), while Locascio serves as chief of MML’s Biochemical Science Division.

Established in 2008, the ACS Fellows Program recognizes members “for outstanding achievements in and contributions to science, the profession and the society.” A total of 568 scientists from academe, industry and government have been selected as fellows during the program’s three years of existence. May and Locascio are the first from NIST to receive the honor and are among 213 in the 2011 class.

May and Locascio will be inducted as fellows during the ACS National Meeting in Denver, Colo., on Aug. 29, 2011.

For more information on the ACS Fellows Program, go to www.acs.org/fellows.

Media Contact: Michael E. Newman, michael.newman@nist.gov, 301-975-3025

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