Technology at a Glance is a quarterly newsletter from the National Institute of Standards and Technology reporting on research results, funding programs, and manufacturing extension and technology services. If you have comments or general questions about this newsletter or if you would like to receive the four-page, color newsletter in hard copy, please email your mailing address to Gail Porter, editor, or call (301) 975-3392. About Technology at a Glance.

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A 3-D View for Tissue Engineering

NIST physical scientist Joy Dunkers positions a polymer scaffold for imaging. © Robert Rathe

NIST scientists have designed a novel combination of microscopes that can peer deep into tissue-engineering scaffolds and monitor the growth and differentiation of cells ultimately intended to develop into implantable organs or other body-part replacements.

The new dual-imaging tool provides a much needed capability for the emerging tissue engineering field, which aims to regenerate form and function in damaged or diseased tissues and organs. Until now, scrutiny of this complicated, three-dimensional process has been limited to the top-most layers
of the scaffolds used to coax and sustain cell development.

Composed of biodegradable polymers or other building materials, scaffolds are seeded with cells that grow, multiply, and assemble into three-dimensional tissues. Whether the cells respond and organize as intended in this synthetic environment depends greatly on the composition, properties, and architecture of the scaffolds’ porous interiors. Tools for simultaneously monitoring microstructure and cellular activity can help scientists to tease apart the essentials of this interactive relationship. In turn, such knowledge can speed development of tissue-engineered products ranging from skin replacements to substitute livers to inside-the-body treatments of osteoporosis.

NIST scientists paired an optical coherence microscope—a high-resolution probe of the scaffold interior—with a confocal fluorescence microscope—used to track cells stained with a fluorescent dye. The instruments provide simultaneous images that can be merged to create a comprehensive rendering of microstructure and cellular activity. By stacking the sectional images, they can create a top-to-bottom movie showing structural and cellular details throughout the scaffold’s volume.

Contact: Joy Dunkers, (301) 975-6841.

Printing Arrays For Flat Displays

“Convergent technology” is one thing—but using your computer’s printer to make a new TV screen?

Not quite, but close. In a breakthrough for low-cost electronics manufacturing, researchers at Palo Alto Research Center (PARC), a Xerox subsidiary, have successfully created a transistor array of the type used to control a flat-panel display using a modified ink-jet printer and semiconductor “ink.”

Still under development, the technique is expected to dramatically lower the cost of the popular displays by replacing more expensive photolithography techniques that dominate display manufacturing. The new technology, co-funded by NIST, is expected to work on either rigid or flexible substrates, and could create whole new opportunities for wall-sized TV’s, unbreakable cell phone displays, computer displays that could roll up like a window shade, and electronic paper.

PARC researchers used a new polymer-based semiconductor ink from Xerox Research Center Canada (XRCC) to build a prototype flat-panel display circuit. Transistor arrays are complex devices with multiple layers of conductors, insulators, and semiconductors. Conventional photolithography uses a multistep process for each layer, first laying down the appropriate material, then creating a pattern for the components, and finally etching or transferring the pattern to the material.

By contrast, PARC’s ink-jet process patterns and prints the components of each layer of the transistor array in one step. A key innovation, according to PARC, was a computer-vision system that ensures precise registration of each layer even if the substrate deforms slightly during the process.

The PARC research is part of a joint R&D partnership with Xerox, Motorola Inc., and Dow Chemical Co. that is co-funded under NIST’s Advanced Technology Program (ATP). The semiconductor polymer ink also was developed under the ATP award.

Contact: Jennifer Ernst, (650) 812-4916, info@parc.com.

Chip Ruler Uses Scattered X-rays

X-ray image produced by a dense array of rectangular circuit features.

A decades-old, X-ray-based method for studying the atomic structure of materials may be the answer to a looming semiconductor industry need—a rugged, high-throughput technology for measuring dimensions of chip circuitry packed with devices approaching
molecular proportions.

A team led by NIST scientists recently reported their initial success in adapting small-angle X-ray scattering (SAXS) to rapidly characterize the size and shape of grid-like patterns with nanometer-scale linewidths. With better than one nanometer (billionth of a meter) precision, the team determined the average size of periodically repeating features arrayed on three chemically different samples much like the intricately patterned polymer masks used to print integrated-circuit designs.

With the size of on-chip devices soon to shrink to below 100 nanometers, current dimensional measurement tools are approaching their limits. The versatile SAXS method, the team suggests, could be an able substitute. It can be used on a wide range of materials to evaluate the quality of surface and subsurface patterns consisting of features considerably smaller than 100 nanometers.

In proof-of-concept experiments supported by the Defense Advanced Research Projects Agency, NIST, and the U.S. Department of Energy, essential data were gathered, within a second, over an area about 40 micrometers on a side—a large swath, nanotechnologically speaking. Images assembled from X-rays deflected by electrons in the samples yielded high-precision meas-urements of linewidths, spaces, line-edge roughness, and feature geometry.

Implementing the SAXS method actually should become easier as feature sizes decrease and near molecular dimensions.

Working with NIST polymer scientists on the team were researchers from ExxonMobil Research Co., Argonne National Laboratory’s Advanced Photon Source, and Shipley Co.

Contact: Wen-Li Wu, (301) 975-6839.

A Bose-Einstein ‘Super Molecule’

False color images of the molecular Bose-Einstein condensate forming.

A super-cold collection of molecules behaving in perfect unison has been created for the first time from a sea of “fermion” atoms by researchers at JILA, a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder (CU-Boulder).

Fermions are a class of particles that are inherently difficult to coax into a uniform quantum state. The ability to meld fermions into this state—a soup of particles that acts like one giant, super molecule—may lead to better understanding of superconductivity, in which electricity flows through certain metals with no resistance.

The work was described in a paper posted Nov. 7 on the informal physics archival Web site at http://arxiv.org and was published online by the journal Nature on Nov. 26. Researchers Deborah S. Jin of NIST and Markus Greiner and Cindy A. Regal of CU-Boulder reported that they created a Bose-Einstein condensate (BEC) of weakly bound molecules starting with a gas of fermionic potassium atoms cooled to 150 nanoKelvin above absolute zero (about minus 273 degrees Celsius or minus 459 degrees Fahrenheit).

The team’s work has produced the “first molecular condensate,” which is closely related to “fermionic superfluidity,” a hotly sought after state in gases that is analogous to superconductivity in metals.

Fermionic superfluidity is superconductivity in another form. Quantum physicists are in a worldwide race to produce fermionic superfluidity because gases would be much easier to study than solid superconductors and such work could lead to more useful superconducting materials.

For more details, see www.nist.gov/public_affairs/releases/super_molecule.htm.

Contact: Deborah Jin, (303) 492-0256, jind@jila.colorado.edu.

Radio Waves ‘See’ Moisture in Walls

Three-dimensional perspective view of a mocked-up wall section. Red circular area at left indicates moisture inside a wall. Intelligent Automation Inc.

The building community soon may have radio vision—a new way to “see” moisture inside walls. NIST building researchers have joined forces with Intelligent Automation Inc. in Rockville, Md., to develop a way to use ultra wide-band radio waves to non-destructively detect moisture within the walls of a building. As any homeowner who’s suffered with leaky plumbing or mold problems will tell you, the current state of the art for pinpointing moisture problem areas relies mostly on guesswork and a drywall saw.

Based on hardware developed by Intelligent Automation, the new NIST technique involves sending a broad range of radio frequencies through typical drywall construction to look for a “moisture” signature in the signal that is reflected back. Laboratory experiments conducted with a simplified wall section made of gypsum board, fiberglass insulation, and oriented strand board (similar to plywood), demonstrated that the new method can locate moisture pockets to within one centimeter.

The presence of water within the model wall produced a stronger reflection of radio waves at specific frequencies. The elapsed time between transmission of the waves and their arrival at a receiving antenna helps determine the location of the water. By processing the reflected signals with computer software, the researchers can create detailed three-dimensional maps that highlight wet areas.

Research is continuing to see how well the apparatus performs with real walls that include studs, wires, pipes, and windows that may complicate the readings. A paper describing the research has been accepted for publication in an upcoming issue of ASHRAE Transactions.

Contact: William Healy, (301) 975-4922.

Seven Receive Baldrige Honors

Four companies, two hospital systems, and one school district were named by President Bush and Commerce Secretary Evans to receive the 2003 Malcolm Baldrige National Quality Award, the nation’s highest honor for quality and performance excellence. This is the most Baldrige Award recipients since the program started in 1988 and the first time that recipients were named in all five Baldrige Award categories.

The 2003 Baldrige Award recipients are: Medrad, Inc., Indianola, Pa. (manufacturing); Boeing Aerospace Support, St. Louis, Mo. (service); Caterpillar Financial Services Corp., Nashville, Tenn. (service); Stoner Inc., Quarryville, Pa. (small business); Community Consolidated School District 15, Palatine, Ill. (education); Baptist Hospital, Inc., Pensacola, Fla. (health care); and Saint Luke’s Hospital of Kansas City, Kansas City, Mo. (health care).

The Baldrige program is managed by NIST in conjunction with the private sector.

The new recipient organizations were selected from among 68 applicants. All seven were evaluated by an independent board of examiners in seven areas: leadership, strategic planning, customer and market focus, information and analysis, human resource focus, process management, and results.

The six-month evaluation process included about 1,000 hours of review and an on-site visit by teams of examiners to clarify questions and verify information in the applications. The seven organizations are expected to be presented with the Baldrige Award in a ceremony in Washington, D.C., early this year.

For more information, see www.nist.gov/public_affairs/releases/2003baldrigewinners.htm.

Software Opens the Door for Natural Ventilation

A lack of rigorous design methods and comprehensive performance data has slowed U.S. acceptance of natural ventilation technology, which proponents argue can increase energy efficiency in commercial buildings as well as improve indoor environmental conditions. NIST’s new LoopDA 1.0 software program (for Loop Design and Analysis) helps fill this critical information gap. The LoopDA simulation tool enables building designers and engineers to determine the size of natural ventilation openings needed to provide desired airflow rates. Previously, building designers have had to make decisions using trial and error or based on past experiences. LoopDA allows users to sketch rooms and vertical sections of a building, the location of natural ventilation openings (e.g., windows, doors, and ducts) and the paths the air should take through the building (e.g., pressure loops). The program then enables designers to estimate the size of the natural ventilation openings needed to control indoor air quality and thermal comfort using an engineering-based design process. See: www.bfrl.nist.gov/IAQanalysis/LOOPDAdesc.htm.
Contact: Stuart Dols, (301) 975-5860.

Detoxifying Sediments with Electrons and UV Light

The concentration of certain toxic organic chemicals in waterway sediments can be reduced by 83 percent using electron beams—the same technology already used to decontaminate mail—NIST and University of Maryland scientists reported in Environmental Science & Technology. In additional experiments, the team found that ultraviolet light also can substantially reduce the concentration of these chemicals. Sediments, soupy mixtures of water and particles of various sizes, are notoriously difficult and expensive to decontaminate. Further, electron beams and ultraviolet light effectively detoxified the banned chemicals known as polychlorinated biphenyls, or PCBs, which can get into the food chain and increase the risk of cancer in humans. Waterways such as the Hudson River have bottom sediments heavily contaminated with PCBs. However, whether electron beams and ultraviolet light are practical decontamination techniques will depend on cost-effectiveness comparisons to existing methods, such as chemical treatment and incineration. Contact: Pedatsur Neta, (301) 975-5635.

Using Artificial Cells as Tiny Test Tubes

Using laser light as tweezers and a scalpel, NIST scientists have demonstrated the use of artificial cells as nanovials for ultrasmall volume chemistry. The approach may be useful for faster, cheaper identification of new pharmaceuticals and for studying cellular-level processes. The artificial cells, called liposomes, are tiny spherical containers that self-assemble from natural fats (phospholipids and cholesterol). Measuring micrometers in diameter, the fluid-filled membranes are currently used in cosmetics and for drug delivery. The NIST team developed an improved method for using liposomes as tiny test tubes for mixing chemicals with volumes measured in trillionths of liters. Their experimental setup allows simultaneous trapping of two liposomes without deforming or stressing their membranes, a problem with some other techniques. They used pairs of infrared lasers (“optical tweezers”) to bring two liposomes into contact and a single ultra-violet laser pulse (the “optical scalpel”) to fuse the two cells together. Once fused, the contents of the two cells mix and react. The optical scalpel achieves cleaner fusion and less leakage of contents than the typical technique using pulsed electric fields. Contact: Kristian Helmerson, (301) 975-4266.

With Neutrons, Partners Pursue the Scent of Success

Get a whiff of this! A new research partnership at NIST is using beams of chilled neutrons to determine how aroma compounds are embedded into assortments of other chemicals that carry and release fragrances in perfumes, detergents, and other scented products. The project aims to improve models for predicting interactions between fragrances and their molecular carriers. The cooperative effort involves researchers from International Flavors & Fragrances (IFF), based in New York City, and NIST. Besides contributing in other ways to product performance, carrier molecules band together and enwrap fragrance ingredients. Detecting how neutrons are scattered as they pass through a sample reveals the locations and shapes of fragrance and carrier molecules over time. The cold, slowed-down neutrons available at the NIST Center for Neutron Research are ideal probes for such research. Contact: Steven Kline, (301) 975-6243 or Chii-Fen Wang, (732) 335-2519,
chii-fen.wang@iff.com.

Digital Cinema—Inside Hollywood's historic Pacific Theater, engineers have set up a new tool based on NIST technology to help the motion picture industry move more smoothly into a digital future. The relatively simple tool—dubbed the stray light elimination tube—improves measurements of contrast and sharpness of images produced with digital projectors. Digital Cinema Lab, a project of the Entertainment Technology Center, is using the NIST-developed device as one of many tools to evaluate the performance of digital projectors. Traditional methods for judging the light output of projectors may introduce error rates of 40 percent or more because ambient light is inadvertently included in the measurement. Contact: Paul Boynton, (301) 975-3014.

Rescue Robots—Opportunities for major strides in robotic search and rescue technology advanced in December when Italy opened a year-round, robot-testing arena in Rome. The arena, patterned after one created by NIST researchers, simulates conditions in collapsed buildings. The facility duplicates arenas in the United States and Japan. Two more arenas based on the NIST design are scheduled to open this year in Germany and Portugal. The arenas host “RoboCupRescue,” a robotic search and rescue team competition designed to advance robot rescue capabilities. During such competitions, both NIST and National Science Foundation-funded researchers videotape the robots and operator interfaces to identify “best in class” algorithms, sensors, and mechanisms. Contact: Adam Jacoff, (301) 975-4235.

Superconducting Cables—New NIST research suggests that next-generation, high-temperature superconductor wire can withstand more mechanical strain than originally thought. As a result, superconductor power cables employing this future wire may be used for transmission grid applications. Using samples fabricated by American Superconductor and Oak Ridge National Laboratory, the NIST researchers found that the advanced wires could stretch almost twice as much as previously believed without cracking and with almost no loss in electricity carrying capacity. Contact: Najib Cheggour, (303) 497-3815, cheggour@boulder.nist.gov.

About Technology at a Glance:

NIST is an agency of the US Department of Commerce's Technology Administration. NIST develops and promotes measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. Technology at a Glance is produced by Public and Business Affairs, NIST, 100 Bureau Dr., Stop 3460, Gaithersburg, Md. 20899-3460. Any mention of commercial products is for information only; it does not imply recommendation or endorsement by NIST. Technology at a Glance Editor: Gail Porter, (301) 975-3392, email: gail.porter@nist.gov. For patent information, call (301) 975-3084.

Technology at a Glance Archive Files