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Tech Beat - June 23, 2010

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Editor: Michael Baum
Date created: June 23, 2010
Date Modified: June 23, 2010 
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NIST Team Advances in Translating Language of Nanopores

National Institute of Standards and Technology (NIST) scientists have moved a step closer to developing the means for a rapid diagnostic blood test that can scan for thousands of disease markers and other chemical indicators of health. The team reports* it has learned how to decode the electrical signals generated by a nanopore—a "gate" less than 2 nanometers wide in an artificial cell membrane.

nanopore image

Each molecule passing through the nanopore can be identified by monitoring the change it causes in an ionic current flowing across the membrane. When different molecules (purple and green objects) enter the pore (green shown in inset), each reduces the current by a certain amount and time period (shown by corresponding color scheme in the current diagram below), depending on both its size and ability to attract nearby ions (red dots). The NIST model can be used to extract this information, which might be used to identify and characterize biomarkers for medical applications.

Credit: NIST
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Nanopores are not new themselves; for more than a decade, scientists have sought to use a nanopore-based electrical detector to characterize single-stranded DNA for genetic sequencing applications. More recently, NIST scientists turned their attention to using nanopores to identify, quantify and characterize each of the more than 20,000 proteins the body produces—a capability that would provide a snapshot of a patient's overall health at a given moment. But while nanopores permit molecules to enter into them one at a time, determining what specific individual molecule has just passed through has not been easy.

To address this problem, members of the NIST team that previously developed a method to distinguish both the size and concentration of each type of molecule the nanopore admits** have now answered the question of just how these single molecules interact with the nanopore. Their new theoretical model describes the physics and chemistry of how the nanopore, in effect, parses a molecule, an understanding that will advance the use of nanopores in the medical field.

"This work brings us one step closer to realizing these nanopores as a powerful diagnostic tool for medical science," says Joseph Reiner, who performed the work with Joseph Robertson, and John Kasianowicz, all of NIST's Semiconductor Electronics Division. "It adds to the 'Rosetta Stone' that will allow us to read what molecules have just passed through a nanopore."

Using their new methods, the team was able to model the interaction of a particular type of large molecule through a nanopore's opening with great accuracy. The molecules were polyethylene glycol (PEG), a well-understood polymer that forms chains of varying length.

"PEG chains can be very long, but each link is very small," Kasianowicz says. "It was a good test because we wanted to see if the nanopore could differentiate between two nearly identical large molecules that differ in length by only a few atoms."

The team's device was able to distinguish among different-sized PEG chains easily, and the model they have developed to describe the PEG-nanopore interactions is encouraging them to think that with further effort, the minuscule sensors can be customized to measure many different molecules quickly. "We could conceivably build an array of many nanopores, each one created to measure a specific substance," Kasianowicz says. "Because each nanopore is so small, an array with one for every protein in the body would still be tiny."

* J.E. Reiner, J.J. Kasianowicz, B.J. Nablo, and J.W. F. Robertson. Theory for polymer analysis using nanopore-based single-molecule mass spectrometry. Proceedings of the National Academy of Sciences, Published online on June 21, 2010, doi: 10.1073/pnas.1002194107

**See http://www.nist.gov/public_affairs/techbeat/tb2007_0510.htm#nanopore

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

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Depth Charge: Using Atomic Force Microscopy to Study Subsurface Structures

Over the past couple of decades, atomic force microscopy (AFM) has emerged as a powerful tool for imaging surfaces at astonishing resolutions—fractions of a nanometer in some cases. But suppose you're more concerned with what lies below the surface? Researchers at the National Institute of Standards and Technology (NIST) have shown that under the right circumstances, surface science instruments such as the AFM can deliver valuable data about sub-surface conditions.

AFM and EFM images

Electric force microscopy can be used to detail structures well below the surface. Left, AFM height image showing the surface of a polyimide/carbon nanotube composite. Right, EFM image revealing the curved lines of subsurface nanotubes.

Credit: NIST
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Their recently published* work with colleagues from the National Aeronautics and Space Administration (NASA), National Institute of Aerospace, University of Virginia and University of Missouri could be particularly useful in the design and manufacture of nanostructured composite materials. Engineers are studying advanced materials that mix carbon nanotubes in a polymer base for a wide variety of high-performance applications because of the unique properties, such as superior strength and electrical conductance, added by the nanotubes. The material chosen by the research team as their test case, for example, is being studied by NASA for use in spacecraft actuators because it may outperform the heavier ceramics now used.

But, says NIST materials scientist Minhua Zhao, "one of the critical issues to study is how the carbon nanotubes are distributed within the composite without actually breaking the part. There are very few techniques available for this kind of non-destructive study." Zhao and his colleagues decided to try an unusual application of atomic force microscopy.

The AFM is actually a family of instruments working on the same basic principal: a delicate needle-like point hovers just above the surface to be profiled and responds to weak, atomic-level forces.  A typical AFM senses so-called "van der Waals forces," very short-range forces exerted by molecules or atoms. This restricts the instrument to the surface of samples.

Instead, the team used an AFM designed to use the stronger, longer-range electrostatic force (technically an EFM), measuring the interaction between the probe tip and a charged plate beneath the composite sample. What makes it work, says Zhao, is that the nanotubes are electrical conductors with high dielectric constant (a measure of how the material affects an electric field), but the polymer is a low dielectric constant material. Such huge dielectric constant differences between nanotubes and the polymer is the key to the success of this technique, and with properly chosen voltages the nanotubes show up as finely detailed fibers dispersed below the composite's surface.

The goal, according to Zhao, is to control the process well enough to allow quantitative measurements. At present the group can discriminate different concentrations of carbon nanotubes in the polymer, determine conductive networks of the nanotubes and map electric potential distribution of the nanotubes below the surface. But the measurement is quite tricky, many factors, including probe shape and even humidity affect the electrostatic force.

The team used a specially designed probe tip and a patented, NIST-designed AFM humidity chamber.** An interesting, not yet fully understood effect, says Zhao, is that increasing the voltage between the probe and the sample at some point causes the image contrast to invert, dark regions becoming light and vice versa. The team is studying the mechanism of such contrast inversion.

"We are still optimizing this EFM technique for subsurface imaging," says Zhao. "If the depth of nanostructures located from the film surface can be determined quantitatively, this technique will be a powerful tool for nondestructive subsurface imaging of high dielectric nanostructures in a low dielectric matrix, with a broad range of applications in nanotechnology."

* M.H. Zhao, X.H. Gu, S.E. Lowther, C. Park, Y.C. Jean and T. Nguyen. Subsurface characterization of carbon nanotubes in polymer composites via quantitative electric force microscopy. Nanotechnology 21 (2010) 225702 doi:10.1088/0957-4484/21/22/225702.

** J.W. Martin, E. Embree and M.R. VanLandingham. Humidity Chamber For Stylus Atomic Force With Cantilever. U.S. Patent No. 6,490,913 B1, Dec. 10, 2002.

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

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Blast Resistance Standards For Trash Receptacles

With summer travel season hard upon us, specialists at the National Institute of Standards and Technology (NIST) have helped create two new standards* designed to increase safety as we rush from gate to gate in crowded mass transit centers. Their efforts will help to fortify against potential bomb threats in the nation's transportation centers.

detonation within a blast resistant trash receptacle

This image shows a detonation within a blast resistant trash receptacle using a large C4 explosive charge. By regulating the explosive force carefully over a series of tests like this one, the research and development team created a scalable blast resistance standard, which can help in comparing a threat assessment with the protection that different trash receptacles provide.

Credit: NIST
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Whether you travel by plane, train or bus, you're bound to pass a familiar container that makes for an attractive spot to stash a bomb: a trash can. Not only does a trash receptacle present an easy place for a terrorist to hide an explosive device before making a quiet getaway, but the metal from a bin can rupture into shrapnel that flies outward in all directions, increasing the risk to passersby.

While industry has been producing blast-resistant trash receptacles for years, there were no widely-accepted specifications for judging a manufacturer's particular claims of product safety. The Science and Technology Directorate of the Department of Homeland Security (DHS) and several manufacturers began working with NIST in 2007 to address the lack of standards for blast resistance among trash receptacles. The results of the DHS-funded work now have been published by the standards development organization ASTM International.

The two standards will allow managers of transit centers—and other venues as well—to know exactly how a given receptacle model has been tested against blasts and precisely what a passing grade means in terms of resistance. The standards are scalable, meaning that they provide useful information on performance at any threat level.

"In practice, this means a transit center manager can make a purchase with confidence in the performance of the unit, the specific threat level anticipated and cost," explains Chris White, a researcher in NIST's Building and Fire Research Laboratory. "If, for example, you know you can, at a minimum, detect the trafficking of five or more pounds of plastic explosive, you can purchase trash receptacles that will redirect the blast at up to that level of explosive force."

A trash receptacle has met the standard if it is capable of directing a blast upward, rather than outward, at a given level of force. While any receptacle will fail to direct the blast upward at some level of force, these two standards will allow a buyer to determine that level with confidence.   

"Using these two standards, any transit agency can reference blast resistance when they do their procurement," White says. "They can go to multiple manufacturers and compare their products on an equal basis."

A third standard is now in the works. It will help guide the placement of trash receptacles in building to minimize safety risks should a bomb detonate inside the containers.

* ASTM International. "E 2639 – 09a, Standard Test Method for Blast Resistance of Trash Receptacles" and "E2740 – 10, Standard Specification for Trash Receptacles Subjected to Blast Resistance Testing". Available at <http://www.astm.org/Standards/E2639.htm>

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

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Proposed Rules Would Allow Metric Only Labeling for Some Products

The National Institute of Standards and Technology (NIST) has issued two publications calling for the amendment of labeling laws to allow the voluntary use of only metric units on some consumer products. NIST researchers suggest that adoption of metric labeling will lead to greater agreement between state and federal labeling laws and simplify domestic and international commerce.

juice cartons showing different types of labeling

From left to right, cartons A and B feature a dual net quantity of contents statement on the label, as required under the current Fair Packaging and Labeling Act (FPLA). Carton C (far right) features only a metric label, as is recommended by the Uniform Packaging and Labeling Regulation (UPLR), but prohibited by the FPLA. A proposed FPLA amendment would permit U.S. manufacturers to choose either dual or metric labeling for their products.

View hi-resolution image

The Fair Packaging and Labeling Act (FPLA) specifies the type of information that must appear on a consumer product label, including the kind of product, name of the manufacturer or responsible party, and net contents. Products that aren't covered by the federal law are regulated by the states, which generally follow the guidance of the Uniform Packaging and Labeling Regulations (UPLR), a publication produced by NIST and the National Conference on Weights and Measures (NCWM). The rules in the UPLR are recommended regulations that only become law if and when adopted by individual states.

In 1992, NIST and the NCWM supported Congress's decision to amend the FPLA to allow manufacturers to label their products with U.S. customary units (inch/pound/pint, etc.) and metric units (centimeter/kilogram/liter, etc.), known as dual unit labeling. Since then, NIST and the NCWM have been working with the states to help them adopt laws that would permit metric only labeling of products under their jurisdiction. Forty-eight states have adopted this approach.

However, some manufacturers worry that the option to label products solely with metric units will confuse consumers and that it will force manufacturers to redesign product packaging.

To allay these concerns, NIST Metric Program coordinator Elizabeth Gentry notes that many products, especially wine and distilled spirits, have been sold with metric-only labels since the early 1980s. A study by her group found that 193 of 1,137 products surveyed in 19 retail stores were labeled with metric units only. More than half of those products were made or distributed by U.S. companies. Moreover, she notes that, under the proposal, use of metric only labeling would be voluntary, as would packaging modifications.

Gentry says there is nothing compelling manufacturers to change package sizing simply because they have the option to use only metric units on their labels. Manufacturers would be free to continue including U.S. customary units (inch/pound/pint, etc.) in the dual unit labeling scheme. The proposed changes to the FPLA would not apply to unit pricing, advertising, recipes, nutrition labeling or other general pricing information.

"We're suggesting these changes to the FPLA in response to requests by U.S. manufacturers and consumers," says Gentry. "Manufacturers want to take control of the limited space on their packaging and giving them the option of using only metric units will offer manufacturers more flexibility."

Download NIST's guide to Voluntary Metric Labeling.

Download NIST's Labeling Marketplace Assessment.

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

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July 27 Stakeholder Meeting Addresses Cybersecurity and Innovation

As part of its initiative to ensure that the Internet continues to spawn growth and innovation, the Department of Commerce will hold a symposium on "Cybersecurity and Innovation in the Information Economy" on July 27, 2010, at the Ronald Reagan Building and International Trade Center in Washington, D.C. Interested stakeholders are invited to comment on the relationship between cybersecurity in the commercial space and innovation in the Internet economy, with particular emphasis on businesses that operate non-critical infrastructure.

Senior government officials scheduled to speak include Commerce Secretary Gary Locke, National Institute of Standards and Technology (NIST) Director Patrick Gallagher, Commerce General Counsel Cameron Kerry, U.S. Chief Technology Officer Aneesh Chopra and White House Cybersecurity Coordinator Howard Schmidt. Private-sector panelists include Vint Cerf, Google; Larry Clinton, Internet Security Alliance; and James Lewis, Center for Strategic and International Studies.

Planned panels will focus on "Assessing the Macro-Economic Threat and the Commercial Sector's Response," "Micro-Economic Successes and Challenges in Risk Management," "Effecting Behavioral Change" and "Roles, Responsibilities and the Global Path Forward."

This meeting is part of an ongoing review conducted by the Commerce Department's Internet Policy Task Force, launched by Secretary Locke in April. The task force is investigating successful cybersecurity strategies, the roles of the private and public sectors in cybersecurity in the commercial arena, and the relationship between cybersecurity policy and consumer welfare, job creation, and international trade. The review is being coordinated with the Office of the Cybersecurity Coordinator, Executive Office of the President.

Task force members include representatives from NIST, the National Telecommunications and Information Administration, and the International Trade Administration.

The event will be held in the Amphitheater of the Ronald Reagan Building, from 8:30 a.m. to 4:15 p.m., and will be open to the public on a first-come, first-served basis. To register and review the agenda, see www.nist.gov/itl/cybersecurity.cfm. The proceedings will be videotaped and available later on the web site.

Media are welcome to attend and should contact Evelyn Brown in advance.

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

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National Initiative For Cybersecurity Education (NICE)ly Comes to You

Cybersecurity training is spreading from high-tech and government offices into high schools, libraries and workplaces near you. Called the National Initiative for Cybersecurity Education (NICE) and coordinated bythe National Institute of Standards and Technology (NIST) , the new interagency program aims to promote cybersecurity awareness and know-how across the country and among citizens of all ages.

NICE is an outgrowth of the 2008 Comprehensive National Cybersecurity Initiative, which called for extending cybersecurity training throughout the federal government. The subsequent Cyberspace Policy Review, completed in May 2009, concurred and also recommended expanding cybersecurity education to all citizens, starting in kindergarten.

"The NICE initiative recognizes that computer technology is an integral part of our society and with that comes the need for everyone to be able to protect themselves and their private information when using the Internet and be able to trust all the other critical cyber infrastructure we all depend on daily," explains NIST's Ernest L. McDuffie, who leads the government-wide initiative." The program's goal is to enhance the security of the country through enhanced awareness and education, which in turn will improve computer security in the workplace and at home, as well as prepare future employees for the cybersecurity workforce."

NICE is divided into four tracks:

National Cybersecurity Awareness is led by the Department of Homeland Security. Public service campaigns will promote cybersecurity and responsible use of the Internet, encourage students to pursue careers in cybersecurity, and motivate interest in the topic among children.

Formal Cybersecurity Education is led by the Department of Education and the Office for Science and Technology Policy. They are responsible for reaching out and increasing knowledge and appreciation of cybersecurity across all levels of education, from kindergarten through college and vocational school. The focus is on the science, technology, engineering and math disciplines, with the aim of creating a pipeline of skilled workers for private and public sector jobs.

Federal Cybersecurity Workforce Structure is led by the Office of Personnel Management (OPM). The workforce team will define cybersecurity jobs in the federal government and skills and competencies required. They will also identify new strategies to ensure federal agencies attract, recruit and retain skilled employees to accomplish cybersecurity missions.

Cybersecurity Workforce Training and Professional Development is led by the Department of Defense, Office of the Director of National Intelligence, and the Department of Homeland Security. This track is divided into four areas that range from law enforcement and counterintelligence to general use of information technology.

For more information on the ongoing NICE projects, check out the NICE web page at www.nist.gov/nice/.

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

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Baldrige Recipients to Share 'Keys to Excellence' at Regional Conferences

Senior leaders from the five organizations selected for the 2009 Malcolm Baldrige National Quality Award, as well as representatives from previous Award recipients, will share their best practices and results at regional conferences on Sept. 14, 2010, at the Newport Beach Marriott Hotel and Spa, Newport Beach, Calif., and on Sept. 28, 2010, at the Franklin Marriott Cool Springs, Nashville, Tenn.

Participants can network with the recipients and gather valuable tips on organizational improvement, innovation and performance management, as well as advice on how to successfully apply the Baldrige Criteria for Performance Excellence. 

The 2009 Baldrige Award recipients—listed with their category—are: 

  • Honeywell Federal Manufacturing & Technologies, Kansas City, Mo. (manufacturing)
  • MidwayUSA, Columbia, Mo. (small business)
  • AtlantiCare, Egg Harbor Township, N.J. (health care)
  • Heartland Health, St. Joseph, Mo. (health care)
  • VA Cooperative Studies Program Clinical Research Pharmacy Coordinating Center, Albuquerque, N.M. (nonprofit) 


Each conference will feature an in-depth plenary session with the Baldrige Award recipients, along with 18 interactive breakout sessions with leaders from these organizations. 

A pre-conference workshop is being offered on the day before both the California and Tennessee conferences to familiarize those new to the Baldrige process with the basics of the Baldrige Criteria, the benefits of self-assessment, and the resources available to help organizations in their journey to excellence. The workshop is not a prerequisite for attending the conference. 

To register online for the conferences, go to http://www.maccinc.com/brc2010. An early registration discount is available for the California conference until Aug. 24, 2010, and for the Tennessee conference until Sept. 7, 2010. 

The 2010 Regional Conferences are co-sponsored by the California Council for Excellence, the Tennessee Center for Performance Excellence and the Alliance for Performance Excellence. 

Visit the website for more information or contact the Baldrige Program at (301) 975-2036 or baldrige@nist.gov.

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

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Pioneer NIST Computer Remembered on 60th Anniversary

Edith Marden

Ethel Marden, National Bureau of Standards (now the National Institute of Standards and Technology) computer programmer, operates the Standards Electronic Automatic Computer (SEAC) during the 1950s.

Credit: NIST
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Sixty years ago this week, the National Bureau of Standards (NBS, now known as the National Institute of Standards and Technology, or NIST) informed the nation about the dedication of the first programmable computer in U.S. history, the Standards Electronic Automatic Computer (SEAC). The revolutionary device moved information as sound wave pulses traveling through 64 mercury-filled glass tubes—in an early data-storage system known as acoustic delay. Each tube had a quartz crystal at both ends, one serving as a transmitter and the other as a receiver. Sound pulses were sent and received repeatedly in a closed loop, recirculating the data patterns they carried and essentially, storing them. It was the electronic equivalent of repeating a telephone number to oneself from the time it is found in the directory until it is dialed.

SEAC had the equivalent of 6,000 bytes of storage (by comparison, a home computer's hard drive has approximately 11 billion bytes). According to Measures for Progress: A History of the National Bureau of Standards by R.C. Cochrane, SEAC "could add or subtract pairs of 11-digit numbers 1,000 times a second, or multiply and divide them 330 times a second." The book also states that "failure of one of its [SEAC's] more than 100,000 connections and components, even for a millionth of a second, would result in a computer malfunction. Yet, often operating nonstop, 7 days a week, SEAC performed for 4,000 hours in the first 9 months without a malfunction." Among the computer's many tasks: computations for the military and the Atomic Energy Commission; calculations on electronic circuit design and for optical lenses; statistical sorting and tabulating for Social Security and the Census Bureau; and processing of data from studies of crystal structure.

Perhaps one of SEAC's most memorable applications occurred in 1957 when NBS researcher Russell Kirsch and colleagues created a rotating drum scanner and the programming that allowed images to be fed into the computer. The first image ever scanned was a grainy, black-and-white shot of Kirsch's three-month-old son, Walden, a picture honored by Life magazine in 2003 as one of "the 100 photographs that changed the world." (For more information, see "Fiftieth Anniversary of First Digital Image Marked," NIST Tech Beat, May 24, 2007).

SEAC served its customers faithfully until 1964 when it was replaced by more advanced computers. In 14 years of active duty, it handled problems and computations in areas such as meteorology, linear programming, optics, navigation, statistics, physics, accounting and manufacturing.

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

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Quicklinks

NIST Fellow Applications Now Being Accepted

Applications for National Institute of Standards and Technology (NIST) measurement science and engineering fellowships—for graduate, post-doctoral and senior researchers—are now being accepted by the University of Maryland and the University of Colorado, which are administering the programs.

In February 2010, NIST awarded a total of $19.5 million to the two institutions to implement and administer the fellowship programs, which were funded under the American Recovery and Reinvestment Act (ARRA) of 2009.

The University of Maryland-administered portion of the program will place successful applicants in positions at either NIST's campus at Gaithersburg, Md., or the Hollings Marine Laboratory (HML) in Charleston, S.C., which is a unique partnership involving NIST, the National Oceanic and Atmospheric Administration, and other of governmental and academic agencies.

Fellows selected by the University of Colorado will be placed at NIST's Boulder, Colo., laboratories.

The fellowship program will continue in 2011 and 2012 and will include undergraduates. Fellowship positions are available for highly-qualified U.S. citizens and non-citizens from academic, industrial and other organizations. For information on the University of Maryland-administered portion of the program, go to: http://www.nistfellows.umd.edu/ For information on the fellowship managed by the University of Colorado, go to: http://www.colorado.edu/nistfellows/

Media Contact: Mark Bello, mark.bello@nist.gov, 301-975-3776

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Five NIST Scientists Win Flemming Awards

Five National Institute of Standards and Technology researchers are among the winners of the prestigious 2009 Arthur S. Flemming Awards. The winners were honored at a ceremony on June 14, 2010.

Steven Brown, physicist in the Laser Applications Group, was recognized for major advances in light measurement and its applications to the environmental remote sensing of the Earth.

Marla Dowell, leader of the Sources, Detectors and Displays Group, received her award for her exceptional leadership of the world's most comprehensive laser metrology program.

John Kitching, leader of the Atomic Devices and Instrumentation Group, was recognized for his outstanding efforts to develop ultra-miniature devices that bring atomic measurement precision to a wide range of applications.

Dietrich Leibfried, physicist in the Ion Storage Group, was honored for research innovations in quantum computing, especially for conceiving and experimentally demonstrating a versatile and productive way to make a quantum bit (qubit), the basic computing element of a quantum computer.

Eite Tiesing, a physicist in the Quantum Processes and Metrology Group, received his award for his prolific work on controlling and understanding the interactions of ultracold atoms. 

Established in 1948, the Flemming awards memorialize Arthur S. Flemming, whose seven decades of service spanned the federal government and higher education. The awards honor outstanding career federal employees who have between three and 15 years of government service and are given for exceptional work in applied science, engineering and mathematics, basic science, and managerial or legal achievement. The George Washington University has administered the awards since 1998.

See the Flemming Award website for more details.

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

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