Saturday, March 31, 2007

A new way to read nanoscale vibrations

Reach out and touch an oscillator: Cornell researchers find a new way to read nanoscale vibrations. By Bill Steele

Schematic of the experimental setup. The probe of an atomic force microscope is suspended just above a vibrating cantilever. Electrostatic forces cause the probe to vibrate, and its vibration is measured by a laser beam.Nanomechanical oscillators -- tiny strips of vibrating silicon only a few hundred atoms thick -- are the subject of extensive study by nanotechnology researchers. They could someday replace bulky quartz crystals in electronic circuits or be used to detect and identify bacteria and viruses.
The catch is that measuring their vibrations isn't easy. It is usually done by bouncing laser beams off them -- which won't work when the nanodevices become smaller than the wavelength of the light -- or with piezoelectric devices -- those bulky quartz crystals we're trying to get rid of.

Now Cornell University researchers have come up with a very simple solution: reach out and touch them. The vibration of the tiny oscillators can be measured by "tapping" with an atomic force microscope (AFM).

An AFM uses a tiny probe that moves slowly just above a surface. Electrostatic attraction or repulsion between the atoms in the tip of the probe and those in the surface causes the probe to move up and down, creating an image of the surface so detailed that individual atoms show up as bumps. Alternatively, the AFM can be used in "tapping mode," literally bouncing off the surface.

"AFMs are all over the place," said Rob Ilic, research associate in the Cornell NanoScale Facility and lead author on a paper about the research published Feb. 23 in the online edition of the Journal of Applied Physics. "So this offers a simple way to study these structures." (Cornell, for example, has at least a dozen AFMs in various labs.) Moreover, he said, probes similar to those in an AFM can be built directly into nanofabricated devices.

This would amount to using MEMS to measure NEMS, he said. MEMS (microelectromechanical systems) are machines with moving parts measured in microns, or millionths of a meter; NEMS (nanoelectromechanical systems) are measured in nanometers, or billionths of a meter. A nanometer is about the length of three atoms in a row. When the NEMS oscillator is too small to be observed by laser light, it could still be coupled to a MEMS probe that in turn would be large enough for a laser readout.

To measure the vibration of a nanomechanical oscillator, the AFM probe moves along the length of the oscillating rod. The result is a complex bouncing interaction between the probe and the oscillator -- imagine shaking one end of a spring and watching the vibrations at the other end -- from which the frequency of vibration of the oscillator can be determined mathematically.

For the experiments just reported, Ilic and colleagues manufactured a wide variety of silicon cantilevers -- strips of silicon attached at one end with the other free to vibrate -- from 5 to 12 microns long, 1/2 to 1 micron wide and about 250 nanometers thick, which had natural vibration frequencies from 1 to 15 Mhz. The cantilevers were set into vibration by a piezoelectric device.

The experimenters first measured the resonant frequencies of the cantilevers by focusing laser beams on them and observing deflection of the reflected light, then scanned each cantilever with the AFM probe, both in tapping mode and with the probe just above the surface. They found the AFM measurements in good agreement with laser measurements, although the AFM readouts had a somewhat lower "quality factor," because the oscillator and probe were interacting. This would make the method somewhat less precise in mass detection.

Nanomechanical oscillators are often cited as potential tools for detecting bacteria, viruses or other organic molecules. An array of tiny cantilevers might be created with antibodies to many different pathogens attached to them. An experimental solution could then be washed over the array, allowing microbes to bind to the cantilevers with matching antibodies. Since the cantilevers are so tiny, an attached bacterium or virus represents a significant change in mass, which changes the frequency at which the oscillator will vibrate.

In a practical device, a MEMS probe could be mounted above each NEMS oscillator to read out which oscillators in the array show a change in frequency -- and thus identify which pathogens are present. ###

Cornell Chronicle: Bill Steele(607) 255-7164 ws21@cornell.edu, Media Contact:
Press Relations Office(607) 255-6074 pressoffice@cornell.edu. March 26, 2007, Related Information: Craighead Research Group

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New metal crystals, formed on a cotton assembly line

A new form of metal crystals, brought to you by a cotton assembly line. First appearance of silver, gold, nickel and other tiny, uniform metal crystals have novel chemical and physical properties

Caption: Left, an electron micrograph (TEM) of a metal, in this case platinum, deposited on cellulose. Inset, crystalline cellulose without metal. Right, TEM showing the pattern of platinum clustering along hydroxyl sites on the cellulose surface. Credit: Pacific Northwest National Laboratory, Usage Restrictions: None.CHICAGO – Appropriating cellulose fibers from cotton and crystallizing them, scientists at Pacific Northwest National Laboratory have grown never-before-seen configurations of metal crystals that show promise as components in biosensors,
biological imaging, drug delivery and catalytic converters.

Deriving the desired chemical and physical properties necessary for those applications hinges on the uniform size of the metal crystals. Depending on the metal, they must be between 2 and 200 nanometers, Yongsoon Shin, a staff scientist at the Department of Energy laboratory in Richland, Wash., reported Monday at the national meeting of the American Chemical Society. PNNL laboratory fellow Gregory Exarhos led the research. Exarhos called Shin's experimental work "the first report of the efficacy of nanocrystalline cellulose templates in driving the formation of ordered metal and metal oxide nanoparticles at surfaces." Exarhos has dubbed these cellulose nanocrystals "molecular factories."

Using acid-treated cellulose fibers from cotton as a natural template, the PNNL team has been able to grow gold, silver, palladium, platinum, copper, nickel and other metal and metal-oxide nanocrystals quickly and of uniform size, Shin said. The metals display catalytic, electrical and optical that would not be present in larger or odd-sized crystals. The acid converts the cellulose to a large, stable crystallized molecule rich in oxygen-hydrogen, or hydroxyl, groups, predictably spaced along the long chemical chains, or polymers, that comprise the cellulose molecule's backbone. When most metal salts dissolved in solution are added in a pressurized oven and heated 70 to 200 degrees centigrade or warmer for four to 16 hours, uniform metal crystals form at the hydroxyl sites.

The researchers called this method a "green process," requiring only heat, the crystalline cellulose and the metal salts. Other attempts to get uniform nanometals have resulted in crystals of widely variable sizes that require strong, caustic chemicals as reducing and stabilizing agents.

"We have some preliminary catalytic results," Shin said, involving "coupling reactions of organic molecules for palladium and UV-irradiated degradation of organic dyes in water with selenium metals. "Smaller particles—15 to 20 nanometers—showed faster and higher catalytic conversion ratio compared to commercial catalysts." # # #

PNNL is a DOE Office of Science national laboratory that solves complex problems in energy, national security and the enironment, and advances scientific frontiers in the chemical, biological, materials, environmental and computational sciences. PNNL employs 4,200 staff, has a $750 million annual budget, and has been managed by Ohio-based Battelle since the Laboratoy's inception in 1965.

PNNL scientist Yongsoon Shin will present this work as part of the 8:30-11 a.m. Monday session on "Nanotechnology: A Fiber Perspective," room E352, level 3, McCormick Place Lakeside.

Contact: Bill Cannon cannon@pnl.gov 509-375-3732 DOE/Pacific Northwest National Laboratory

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Friday, March 30, 2007

Nanoparticles can track cells deep within living organisms

Nanoparticles can track cells deep within living organisms. By Gwen Ericson

This image combines three MRI scans of a mouse: one is a typical scan showing internal organs, and the second two are scans tuned to the frequency of fluorine-laced nanoparticles (colored red and green).March 26, 2007 -- To the delight of researchers at Washington University School of Medicine in St. Louis, living cells gobbled up fluorine-laced nanoparticles without needing any coaxing. Then, because of the unusual meal, the cells were easily located with MRI scanning after being injected into mice.
Developed in the laboratories of Samuel A. Wickline, M.D., and Gregory Lanza, M.D., Ph.D., the nanoparticles could soon allow researchers and physicians to directly track cells used in medical treatments using unique signatures from the ingested nanoparticle beacons.

In an article that will appear in the June issue of the FASEB Journal, lead author Kathryn C. Partlow, a doctoral student in Wickline's lab, describes using perfluorocarbon nanoparticles to label endothelial progenitor cells taken from human umbilical cord blood. Such cells can be primed to help build new blood vessels when injected into the body. The researchers believe nanoparticle-labeled stem cells like these could prove useful for monitoring tumors and diagnosing and treating cardiovascular problems.

The nanoparticles contain a fluorine-based compound that can be detected by MRI scanners. Fluorine is most commonly known for being an element included in fluoride toothpastes. Wickline, who heads the Siteman Center of Cancer Nanotechnology Excellence, says this technology offers significant advantages over other cell-labeling technologies under development.

"We can tune an MRI scanner to the specific frequency of the fluorine compound in the nanoparticles, and only the nanoparticle-containing cells will be visible in the scan," he says. "That eliminates any background signal, which often interferes with medical imaging. Moreover, the lack of interference means we can measure very low amounts of the labeled cells and closely estimate their number by the brightness of the image."

The researchers believe that nanoparticle-labeled adult stem cells could be used to evaluate tumors. Under an MRI scan, the presence of the labeled cells would reveal that the tumor was adding new blood vessels and therefore aggressively growing.

Adult stem cells are also under investigation in therapies that enhance new blood vessel growth to improve the blood supply to diabetic patients' limbs or to repair blood vessels after a heart attack or bypass surgery. Tracking nanoparticle-labeled cells used in such treatments by MRI imaging would allow physicians to monitor the treatment's success or failure.

The nanoparticles — called "nano" because they measure only about 200 nanometers across, or 500 times smaller than the width of a human hair — are made up largely of perfluorocarbon, a safe compound used in artificial blood. The fluorine atoms in the particles can be detected by tuning an MRI scanner to the unique signal frequency emitted by the perfluorocarbon compound used.

Since several perfluorocarbon compounds are available, different types of cells potentially could be labeled with different compounds, injected and then detected separately by tuning the MRI scanner to each one's individual frequency, says Wickline.

That makes the labeled cells potentially useful for vascular research as well. "Many kinds of cells are involved in the formation of new blood vessels," Partlow says. "Because we can create a separate MRI signature for different cells with these various types of unique nanoparticles, we could use them to better understand each cell type's role."

The nanoparticles are very compatible with living cells, according to the research findings. "The cells just take these particles in naturally — no special sauces have to be added to make them tasty to these cells," says Wickline, also professor of medicine, of physics and of biomedical engineering and a Washington University heart specialist at Barnes-Jewish Hospital. "And then the cells just go about their business and do what they're supposed to do by homing in on targeted regions of the body."

Laboratory tests showed that the cells retained their usual surface markers and that they were still functional after the labeling process. The labeled cells were shown to migrate to and incorporate into blood vessels forming around tumors in mice.

The researchers believe the cells could soon be used in clinical settings. "Kathy and colleagues showed that we can scan for these cells at the same MRI field strength we are using in medical imaging," Wickline says. "Although we reported the first use of perfluorocarbon molecular imaging for detection of certain pathologies a few years ago, no one would have predicted that you could get enough signal from such small quantities of perfluorocarbons in labeled stem cells to actually see them. I think we've dispelled that notion, and the fluorine imaging approach already is becoming more popular for molecular imaging of various cell and tissue types."

Next the research group will evaluate how nanoparticle-labeled cells function in living organisms. "We'll track injected cells in real time and see where they accumulate and how long they live," Partlow says. "Then we'll go on to investigate how they work in therapeutic applications."

Partlow KC, Chen J, Brant JA, Neubauer AM, Meyerrose TE, Creer MH, Nolta JA, Caruthers SD, Lanza GM, Wickline SA. 19F magnetic resonance imaging for stem/progenitor cell tracking with multiple unique perfluorocarbon nanobeacons. FASEB J 2007 Feb 6 (advanced online publication).

Funding from the National Institutes of Health and the American Heart Association supported this research.

Washington University School of Medicine's full-time and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked fourth in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

Siteman Cancer Center is the only NCI-designated Comprehensive Cancer Center within a 240-mile radius of St. Louis. Siteman Cancer Center is composed of the combined cancer research and treatment programs of Barnes-Jewish Hospital and Washington University School of Medicine.

Contact: Gwen Ericson ericsong@wustl.edu 314-286-0141 Washington University School of Medicine

Media Assistance: Gwen Ericson Assistant Director of Research Communications ericsong@wustl.edu (314) 286-0141

Related Links:
Lanza's Web pageWickline's Web pageNanomedicine Web page

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Thursday, March 29, 2007

Nanocrystal research new vaccine and computer inks

Nanocrystal research could lead to new vaccine and computer inks By Lynn Davis

Maren Roman, assistant professor in the wood science and forest products department of the College of Natural Resources at Virginia Tech.BLACKSBURG, VA., March 28, 2007 -- Maren Roman, assistant professor in the wood science and forest products department of the College of Natural Resources at Virginia Tech, is taking nanocrystal research to a new level that may lead to a new generation of vaccines and better computer printer ink.
Roman delivered her findings at the American Chemical Society 233rd National Meeting and Exposition in Chicago, held March 25-29. The focus of her research deals with cellulose drug delivery and ink jet printing.

Roman experimented with taking cellulose nanocrystals and attaching antibodies to the surface of the crystals. This design enables the nanocrystals to block cell receptors in the body. The process may eventually be used to create vaccines. Through the same receptor-blocking method, this process can combat the effects of some diseases involving inflammation of blood vessels, including diabetes, rheumatoid arthritis, and certain cancers.

The poster, “Cellulose nanocrystals as targeted drug delivery systems” (Cell 82), was presented on Sunday, March 25, as part of the Cell general posters session, and on Sunday, March 26, 8 to 10 p.m., as part of the Sci-Mix session. Authors of the poster are Roman, Shuping Dong, a Ph.D. candidate in wood science and forest products and part of the Macromolecular Science and Engineering graduate degree program at Virginia Tech; graduate student Anjali A. Hiran and Assistant Professor of Cellular and Molecular Biology Yong Woo Lee, both with the Virginia Tech-Wake Forest School of Biomedical Engineering and Sciences.

Ink jet printing was another research project for Roman. She experimented with using ink jet printers to deposit the crystals because the printers’ main focus is precision. Nanocrystals are tiny and pose many difficulties to the people using them. A typical remedy involves converting the nanocrystals to a powder. This has risks as well, as the powder can be a serious health hazard if inhaled. The ink jet printing allows for a safe method of deposition of the nanocrystals.

Roman delivered the talk, “Ink-jet printing of cellulose nanocrystal suspensions” (Cell 98) on Monday, March 26, at the McCormick Place Lakeside. The paper is authored by Fernando Navarro, a graduate student in the Macromolecular Science and Engineering Program at Virginia Tech, and Roman.

The College of Natural Resources at Virginia Tech consistently ranks among the top five programs of its kind in the nation. Faculty members stress both the technical and human elements of natural resources and instill in students a sense of stewardship and land-use ethics. Areas of studies include environmental resource management, fisheries and wildlife sciences, forestry, geospatial and environmental analysis, natural resource recreation, urban forestry, wood science and forest products, geography, and international development.

Contact Lynn Davis at davisl@vt.edu or (540) 231-6157. ##07184##

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Wednesday, March 28, 2007

Linear arrays of nanotubes offer path to high-performance electronics

Linear arrays of nanotubes offer path to high-performance electronics

Scanning electron microscope image of a pattern of aligned, linear single-walled carbon nanotubes formed by chemical vapor deposition <br />growth on a quartz substrate. The bright horizontal stripes correspond to the regions of iron catalyst. Photo courtesy John A. Rogers.CHAMPAIGN, Ill. — Despite the attractive electrical properties and physical features of single-walled carbon nanotubes, incorporating them into scalable integrated circuits has proven to be a challenge because of difficulties in manipulating and positioning these molecular scale objects and in achieving sufficient current outputs.
Now, researchers at the University of Illinois, Lehigh University and Purdue University have developed an approach that uses dense arrays of aligned and linear nanotubes as a thin-film semiconductor material suitable for integration into electronic devices.Scanning electron microscope image of a pattern of aligned, linear single-walled carbon nanotubes formed by chemical vapor deposition <br />growth on a quartz substrate. The bright horizontal stripes correspond to the regions of iron catalyst. Photo courtesy John A. Rogers.
John A. Rogers, a Founder Professor of Materials Science and Engineering, says this is the 'first study that shows properties in scalable device configurations that approach the intrinsic properties of the tubes themselves, as inferred from single-tube studies.' University of Illinois Photo.The nanotube arrays can be transferred to plastic and other unusual substrates for applications such as flexible displays, structural health monitors and heads-up displays. The arrays also can be used to enhance the performance of devices built with conventional silicon-based chip technology.
“The aligned arrays represent an important step toward large-scale integrated nanotube electronics,” said John A. Rogers, a Founder Professor of Materials Science and Engineering at Illinois, and corresponding author of a paper accepted for publication in the journal Nature Nanotechnology, and posted on its Web site.

To create nanotube arrays, the researchers begin with a wafer of single-crystal quartz, on which they deposit thin strips of iron nanoparticles. The iron acts as a catalyst for the growth of carbon nanotubes by chemical vapor deposition. As the nanotubes grow past the iron strips, they lock onto the quartz crystal, which then aligns their growth.

The resulting linear arrays consist of hundreds of thousands of nanotubes, each approximately 1 nanometer in diameter (ananometer is 1 billionth of a meter), and up to 300 microns in length (a micron is 1 millionth of a meter). The nanotubes are spaced approximately 100 nanometers apart.

The arrays function as an effective thin-film semiconductor material in which charge moves independently through each of the nanotubes. In this configuration, the nanotubes can be integrated into electronic devices in a straightforward fashion by conventional chip-processing techniques.

A typical device incorporates approximately 1,000 nanotubes, and can produce current outputs 1,000 times higher than those of previously reported devices that incorporate just a single nanotube. Many devices can be built from each array, with good device-to-device uniformity. Detailed theoretical analysis of these unusual devices reveals many aspects of their operation.

Using the arrays, the researchers built and tested a number of transistors and logic gates, and compared the properties of nanotube arrays with those of individual nanotubes.

“This is the first study that shows properties in scalable device configurations that approach the intrinsic properties of the tubes themselves, as inferred from single-tube studies,” said Rogers, who also is a researcher at the university’s Beckman Institute.

Nanotube arrays aren’t likely to replace silicon, Rogers said, but could be added to a silicon chip and exploited for particular purposes, such as higher speed operation, higher power capacity and linear behavior for enhanced functionality. They can also be used in applications such as flexible devices, for which silicon is not well suited.

“Nanotubes have shown potential in the past, but there hasn’t been a clear path from science to technology,” said Moonsub Shim, a professor of materials science and engineering at Illinois, and a co-author of the paper. “Our work seeks to bridge this gap.”

With Rogers and Shim, co-authors of the paper are postdoctoral research associate Seong Jun Kang and graduate students Coskun Kocabas and Taner Ozel, all at Illinois; electrical and computer engineering professor Muhammad A. Alam and graduate student Ninad Pimparkar at Purdue, and physics professor Slava V. Rotkin at Lehigh.

The National Science Foundation and the U.S. Department of Energy funded the work.Editor’s note: To reach John Rogers, call 217-244-4979; e-mail: jrogers@uiuc.edu.

James E. Kloeppel, Physical Sciences Editor 217-244-1073; kloeppel@uiuc.edu. Released 3/26/07

News Bureau, University of Illinois at Urbana-Champaign , 807 South Wright Street, Suite 520 East, Champaign, Illinois 61820-6261 Telephone 217-333-1085, Fax 217-244-0161, E-mail news@uiuc.edu

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Tuesday, March 27, 2007

Risk, Not all nanomaterials are created equal

When it comes to risk, not all nanomaterials are created equal.

Caption: Acid-Treated Nanotubes Interact with Rat Muscle Cells for 3.5 Days, Credit: Rensselaer Polytechnic Institute, Usage Restrictions: NoneTroy, N.Y. – The size, type, and dispersion of nanomaterials could all play a role in how these materials impact human health and the environment, according to two groups of researchers at Rensselaer Polytechnic Institute.
In new studies, the teams found that while carbon nanotubes inhibited growth in mammalian cells, they sustained the growth of commonly occurring bacteria.

The seemingly contradictory findings highlight the need for society to better grasp the impacts these infinitesimally small particles could have when released into the environment or the human body, the researchers said. Both results were presented at the 233rd American Chemical Society (ACS) National Meeting in Chicago, March 25-29, 2007.
In the first study, which was led by Assistant Professor of Biomedical Engineering Deanna M. Thompson, researchers examined the impact of carbon nanotubes on the growth of rat heart muscle cells to better understand how they affect mammalian cells — and ultimately human tissue and organs.Caption: Acid-Treated Nanotubes Interact with E. Coli for 15.5 Days. Credit: Rensselaer Polytechnic Institute, Usage Restrictions: None.
Unlike previous research that focused on the effects of nanotube clusters on cell growth, this study looked at both the impacts of clusters and related finely dispersed material composed of small bundles of nanotubes and other nanoparticulate impurities.

The researchers discovered that the finely dispersed material, despite its low concentration, inhibited animal cell growth more than larger clusters of nanotubes. Activated carbon, a commonly used nanoporous carbon material, had a lower impact on the cells than either the large aggregates or the finely dispersed material. The findings of this study were recently published in the journal Toxicology Letters.

In the second study, which was led by Anurag Sharma, assistant professor of earth and environmental sciences, researchers monitored bacterial growth in the presence of carbon nanotubes to help better understand how the introduction of nanoscale materials might impact the environment over an extended period of time. Escherichia coli (E. coli), a commonly occurring bacterium in nature, was used as the model bacterial species.

The study revealed that while the nanotubes sustained bacterial growth, they also promoted considerable elongation of the E. coli in some instances. This finding indicates that the nanotubes may have induced a stress-related impact on the biological activity of the bacteria. This elongation was not observed with other carbon nanomaterials such as activated carbon or C60 fullerenes, which are commonly referred to as “buckyballs.”

“It appears that in order to see a real environmental impact of nanomaterials, a significantly long duration study similar to ours is needed to get further insight into the physiology of biological interactions in general, and bacterial interactions in particular,” said Pavan Raja a doctoral candidate in chemical and biological engineering who worked on both research teams.

Taken together, the two studies suggest that different nanomaterials and associated parameters could have widely different impacts on human health and the environment. “These findings highlight the underlying need for further research to correlate in detail the different types of nanomaterials and their modes of interaction with biological systems, to promote safe and optimized applications of nanotechnology,” said Raja.

For the first study, Raja worked under Thompson’s leadership along with several other Rensselaer researchers: senior biomedical engineering student Jennifer Connolley; research engineer Gopal P. Ganesan; postdoctoral research associate Lijie Ci, Professor and former Vice President of Research Omkaram Nalamasu; and Pulickel M. Ajayan, the Henry Burlage Professor of Materials Science and Engineering

For the second study, Raja worked with Ganesan under the lead of Sharma, Nalamasu, and Ajayan.

[NOTE TO EDITORS: ENVR 23, “Microbial interactions of carbon nanomaterials,” will be presented March 25 at 4:10 p.m., McCormick Place South, Room S403A, Level 4. INOR 536, “Impact of carbon nanomaterial size regimes on smooth muscle cell growth,” will be presented March 26 at 3:50 p.m., McCormick Place Lakeside, Room E253D, Level 2.]

About Rensselaer Rensselaer Polytechnic Institute, founded in 1824, is the nation’s oldest technological university. The university offers bachelor’s, master’s, and doctoral degrees in engineering, the sciences, information technology, architecture, management, and the humanities and social sciences. Institute programs serve undergraduates, graduate students, and working professionals around the world. Rensselaer faculty are known for pre-eminence in research conducted in a wide range of fields, with particular emphasis in biotechnology, nanotechnology, information technology, and the media arts and technology. The Institute is well known for its success in the transfer of technology from the laboratory to the marketplace so that new discoveries and inventions benefit human life, protect the environment, and strengthen economic development. ###

Contact: Gabrielle DeMarco demarg@rpi.edu 518-276-6542 Rensselaer Polytechnic Institute

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Monday, March 26, 2007

Nanoparticles don't harm soil ecology

Test finds manufactured nanoparticles don't harm soil ecology

WEST LAFAYETTE, Ind. - The first published study on the environmental impact of manufactured nanoparticles on ordinary soil showed no negative effects, which is contrary to concerns voiced by some that the microscopic particles could be harmful to organisms.

Fullerene (C60), purdue.eduScientists added both dry and water-based forms of manufactured fullerenes - nanosized particles also known as buckyballs - to soil. The nanoparticles didn't change how the soil and its microorganisms functioned, said Ron Turco, a Purdue University soil and environmental microbiologist.
Concerns surround the increased use of nanoparticles in everything from car bumpers, sunscreen and tennis balls to disease diagnosis and treatment. Questions have arisen about whether the microscopic materials could trigger diseases if they enter the soil or water through manufacturing processes or if medicines based on nanoparticles behave in unexpected ways in the body.

Turco's research team designed its study to test how different levels of buckyballs affect soil microorganisms, including bacteria that are responsible for breaking down organic material and producing carbon dioxide and other compounds. Results of the study are published online and in the April 15 issue of the journal Environmental Science and Technology.

The scientists collected information from soil found in farm fields, and then they mixed in buckyballs. The research results will serve as baseline data for comparison as research progresses on all types and sizes of nanomaterials, said Turco, the study's senior author.

"Fullerenes will be in the soil eventually, so it's good to know they aren't affecting soil microorganisms," he said. "Bacteria in the soil are the basis of the food chain, so you don't want to change them because then you affect everything up the food chain - plants, animals, people."

Two levels of carbon-based buckyballs were tested in soil collected from no-till plots at the Purdue University Agriculture Research and Education Center located northwest of the campus.

Dry buckyballs and buckyballs suspended in water were added to the soil in levels of one part per million parts of soil and 1,000 parts per million parts of soil. Over a six-month period, the scientists monitored the size, composition and function of the bacterial community in the soil samples.

Carbon dioxide levels in the soil, or soil respiration, the soil microbes' response to added nutrients, and enzyme activities in the soil were measured. No significant differences were found in soil containing no added nanoparticles and soil samples with either the low-level or high-level of buckyballs, the researchers reported.

If buckyballs were toxic to the soil environment, a reduction in the rate of carbon dioxide production, bacterial community activity and size, and enzyme activity would be expected, Turco said. Enzymes are produced as the bacteria degrade things such as organic matter.

"We thought we would see something negative in soil due to effects of fullerenes, especially at 1,000 parts per million," he said. "Lo and behold, much to our pleasure and surprise, our data shows no adverse effects on the soil microbiology."

Although some previous studies by other scientific groups concluded that buckyballs are toxic to microbes and, therefore, would be harmful to plants and animals if released into soil, Turco's research team doesn't believe that's the case.

"The results that have shown a negative effect from fullerenes are important and suggest a need for further investigation, but they did their studies in a purified culture," Turco said. "You can't look at the effects of manufactured nanoparticles in isolation. You have to put them in a natural environment where other things are reacting with the nanoparticles."

Naturally occurring microbes, organic matter and salts in the soil controlled the exposure level and toxicity of fullerenes, Turco said.

Purdue researchers are continuing a number of different studies on varying concentrations of nanoparticles of different sizes and made of different materials to find out if their effects vary from those found so far, he said. Nanoparticles range in size from 1 billionth to 100 billionths of a meter and can be many different shapes.

"Clearly, each manufactured nanomaterial is different so we do need to develop a better knowledge of each on a case-by-case basis," Turco said.

Buckyballs, or fullerenes, are multisided, nanosized particles that look like hollow soccer balls. The full name for the cluster of carbon atoms is buckminsterfullerene, after the American architect R. Buckminster Fuller. His design for the geodesic dome is much like the shape of Buckyballs.

First found in a meteorite in 1969, buckyballs are among three known naturally occurring pure carbon molecules. The others are graphite and diamonds. Experts say that tiny carbon-based manufactured nanotubes are 100 to 1,000 times stronger than steel. Turco and his colleagues will study nanotubes in future research.

In 1985 researchers began making buckyballs, which led to a Nobel Prize for two Rice University scientists.

The other researchers involved in the Purdue study were Larry Nies, civil engineering professor; Bruce Applegate, food science associate professor; and graduate research assistant Zhonghua Tong and research soil microbiologist Marianne Bischoff, both of the Purdue Laboratory for Soil Microbiology.

Turco is a professor in the Purdue Department of Agronomy and director of the Indiana Water Resources Research Center. All the researchers involved in this study are part of the Purdue Nanoscale Interdisciplinary Research Team.

The National Science Foundation and the Environmental Protection Agency are funding the project.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu, Source: Ron Turco, (765) 494-8077, turco@purdue.edu, Ag Communications: (765) 494-2722; Beth Forbes, forbes@purdue.edu On the Web: Agriculture News Page

ABSTRACT: Impact of Fullerene (C60) on a Soil Microbial Community

Zhonghua Tong, Marianne Bischoff, Loring F. Nies, Bruce Applegate and Ronald F. Turco

The nascent state of the nanoproduct industry calls for important early assessment of environmental impacts before significant releases have occurred. Clearly, the impact of manufactured nanomaterials on key soil processes must be addressed so that an unbiased discussion concerning the environmental consequences of nanotechnology can take place.

In this study, soils were treated with either 1 ?g C60 g-1 soil in aqueous suspension (nC60) or 1000 ?gC60 g-1 soil in granular form, a control containing equivalent tetrahydrofuran residues as generated during nC60 formation process or water and incubated for up to 180 days. Treatment effects on soil respiration, both basal and glucose-induced, were evaluated.

The effects on the soil microbial community size was evaluated using total phospholipid derived phosphate. The impact on community structure was evaluated using both fatty acid profiles and following extraction of total genomic DNA, by DGGE after PCR amplification of total genomic DNA using bacterial variable V3 region targeted primers.

In addition, treatment effects on soil enzymatic activities for ?-glucosidase, acidphosphatase, dehydrogenase, and urease were followed. Our observations show that the introduction of fullerene, as either C60 or nC60, has little impact on the structure and function of the soil microbial community and microbial processes.

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Sunday, March 25, 2007

Nano coalition launches virtual journal on risk research

ICON--International Council on Nanotechnology: A partnership for nanotechnology stewardship and sustainability

Nano coalition launches virtual journal on risk research, ICON’s online journal will improve access to information in peer-reviewed articles

The nanotechnology coalition that launched the first online database of scientific findings related to the benefits and risks of nanomaterials has taken the concept one step further with the launch today of The Virtual Journal of Nanotechnology Environment, Health & Safety (VJ-Nano EHS). The journal may be accessed at icon.rice.edu/virtualjournal.

A monthly online journal that contains citations and links to articles on the environment and health impacts of nanotechnology, VJ-Nano EHS is a product of The International Council on Nanotechnology (ICON) and Rice University’s Center for Biological and Environmental Nanotechnology (CBEN), which launched the first EHS database in August 2005.

ICON is an international organization with members from academia, non-governmental organizations, industry and government dedicated to the safe, responsible and beneficial development of nanotechnology. Its EHS database was the first effort to integrate the vast and diverse scientific literature on the impacts of nanoparticles, which are tiny pieces of matter with dimensions measuring between 1-100 nanometers and containing between tens and thousands of atoms.

By virtue of their size, shape or surface characteristics, many nanoparticles exhibit properties that aren’t observed in the bulk form of the same material. With nanomaterials currently being used in hundreds of consumer products, including cosmetics, fabrics, and computer hardware, it is important to understand the potential risks of nanoparticles to living organisms. VJ-Nano EHS provides the most comprehensive knowledge base of peer-reviewed information focusing on nanomaterial impacts available to-date.

"One of the main purposes of our organization is to communicate reliable information on the potential environmental and health risks of nanotechnology in a way that is accessible to both the research community and non-technical audiences," said Kristen Kulinowski, director of ICON. "We believe this new journal provides us with that opportunity."

VJ-Nano EHS organizes the information contained in ICON’s existing EHS Database into a reader-friendly monthly journal format, with articles listed in each issue primarily published during that month. New features include a rotating guest editorship, and a series of occasional papers on topics of interest taken from the contents of the database. In addition, users can subscribe to an RSS feed to receive citations to the latest papers. ICON is working to make more of the papers themselves accessible.

Contents can be browsed by author, journal, or date or by method of study, exposure or hazard target, paper type, risk exposure group, production, particle type, exposure pathway, content emphasis and target audience. In the future, the journal will include a section on the "most-cited Nano EHS papers."

VJ-Nano EHS and its database are maintained by ICON as a public service. ICON is associated with CBEN at Rice University.

Margot Dimond, ICON 713-426-4111 margot@doubledimondpr.com
Jade Boyd, Rice University, 713-348-6778 jadeboyd@rice.edu

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Saturday, March 24, 2007

Alphabet at the Microscale; Research Could Lead to Tiny Devices

Caption: UCLA professor Thomas G. Mason and chemistry graduate student Carlos J. Hernandez have designed and mass-produced billions of fluorescent microscale particles in the shapes of all 26 letters of the alphabet in a 'colloidal alphabet soup.' Credit: Carlos J. Hernandez/Thomas G. Mason, UCLA Chemistry.UCLA Scientists Create Each Letter of the Alphabet at the Microscale; Research Could Lead to Tiny Devices. High Resolution Image
UCLA scientists have designed and mass-produced billions of fluorescent microscale particles in the shapes of all 26 letters of the alphabet in an "alphabet soup" displaying "exquisite fidelity of the shapes."
Caption: UCLA professor Thomas G. Mason and chemistry graduate student Carlos J. Hernandez produced microscale particles shaped like each letter of the alphabet. Graduate student James Wilking used 'laser tweezers' to pick up the letters 'U, C, L, A' and move them in order 'like skywriting in solution.' Credit: James N. Wilking/Thomas G. Mason, UCLA Chemistry.The letters are made of solid polymeric materials dispersed in a liquid solution. The research will be published March 29 in the Journal of Physical Chemistry C, where it will be illustrated on the cover. The scientists anticipate that their "LithoParticles" will have significant technological and scientific uses. High Resolution Image
"We can even choose the font style; if we wanted Times New Roman, we could produce that," said study co-author Thomas G. Mason, a UCLA associate professor of chemistry who holds UCLA's John McTague Career Development Chair.

Lead author Carlos J. Hernandez, a UCLA chemistry graduate student, designed a customized font for the letters and produced them.

"We have demonstrated the power of a new method, at the microscale, to create objects of precisely designed shapes that are highly uniform in size," said Mason, a member of UCLA's California NanoSystems Institute. "They are too small to see with the unaided eye, but with an optical microscope, you can see them clearly; the letters stand out in high fidelity. Our approach also works into the nanoscale."

Hernandez and Mason also have produced particles with different geometric shapes, including triangles, crosses and doughnuts, as well as three-dimensional "Janus particles," which have two differently shaped faces.

"We have made fluorescent lithographic particles, we have made complex three-dimensional shapes and, as shown by UCLA postdoctoral fellow Kun Zhao, we can assemble these particles, for example, in a lock-and-key relationship," said Mason, whose research is at the intersection of chemistry, physics, engineering and biology. "We can mass-produce complex parts having different controlled shapes at a scale much smaller than scientists have been able to produce previously. We have a high degree of control over the parts that we make and are on the verge of making functional devices in solution. We may later be able to configure the parts into more complex and useful assemblies.

"How can we control and direct the assembly of tiny components to make a machine that works?" Mason asked. "Can we cause the components to fit together in a controlled way that may be useful to us? Can we create useful complex structures out of fundamental parts, in solution, where we can mass-produce a small-scale engine, for example? We will pursue these research questions."

Because each letter is smaller than many kinds of cells, possible applications include marking individual cells with particular letters. It may be possible, Mason said, to use a molecule to attach a letter to a cell's surface or perhaps even insert a letter inside a cell and use the letter-marker to identify the cell. The research also could lead to the creation of tiny pumps, motors or containers that could have medical applications, as well as security applications.

In addition to creating the letters, Mason's research group can pick up letters and reposition and reorient them in a microscale version of the game Scrabble (see image).

"We have used 'laser tweezers' to pick up the jumbled letters 'U, C, L, A' and move them together in order, like skywriting in solution," Mason said. UCLA chemistry graduate student James Wilking moved the letters to spell "UCLA."

Mason's research is funded in part by the National Science Foundation. He also receives research support from UCLA's John McTague Career Development Chair, which provides research funding for five years.

"UCLA's Office of Intellectual Property has applied for patent protection on this platform technology and is beginning to speak with potential corporate partners to bring new products to market based on this technology to benefit the public good," said Earl Weinstein, who handles technology business development and licensing for UCLA's technology transfer office.

As a graduate student at Princeton in the early 1990s, Mason founded a field called "thermal microrheology," the techniques of which are now used by scientists worldwide. Microrheology is a method for examining the viscosity and elasticity of soft materials, including liquids, polymers and emulsions, on a microscopic scale. Mason and Hernandez's research in the Journal of Physical Chemistry C provides novel probes for microrheology.

For centuries, scientists and engineers have studied the deformation and flow, or rheology, of soft materials on a large, laboratory scale. However, until Mason developed the field of microrheology, which relies on the random Brownian motion of probe particles, scientists had not done so on the microscopic level.

As with much cutting-edge science, Mason's research opens up the possibility for developments that sound like science fiction. Are microscale devices that can actively identify cancer cells and eliminate them a real possibility? Could Mason's research help achieve this goal? The answer, he said, will probably not come anytime soon, but perhaps in his lifetime. Understanding microrheology in synthetic materials is the first step to understanding what occurs in active materials like the interior of cells and may help us understand how cells function while alive and how they die.

The Journal of Physical Chemistry C publishes research on novel materials, nanoparticles and nanostructures.

For information about Mason's research, visit: chem.ucla.edu/Mason.

Contact: Stuart Wolpert swolpert@support.ucla.edu 310-206-0511 University of California - Los Angeles

About UCLA - California's largest university, UCLA enrolls approximately 38,000 students per year and offers degrees from the UCLA College of Letters and Science and 11 professional schools in dozens of varied disciplines. UCLA consistently ranks among the top five universities and colleges nationally in total research-and-development spending, receiving more than $820 million a year in competitively awarded federal and state grants and contracts. For every $1 state taxpayers invest in UCLA, the university generates almost $9 in economic activity, resulting in an annual $6 billion economic impact on the Greater Los Angeles region. The university's health care network treats 450,000 patients per year. UCLA employs more than 27,000 faculty and staff, has more than 350,000 living alumni and has been home to five Nobel Prize recipients.

-UCLA- SW126

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Friday, March 23, 2007

Mechanics meets chemistry in new ways to manipulate matter

CHAMPAIGN, Ill. — The inventors of self-healing plastic have come up with another invention: a new way of doing chemistry.

An overlay of images at successive stages of force-induced chemical change. The blue image is the start of the reaction. The yellow image represents the end of the reaction. Graphic by Ashley Levato.An overlay of images at successive stages of force-induced chemical change. The blue image is the start of the reaction. The yellow image represents the end of the reaction. Graphic by Ashley Levato.
Nancy Sottos, professor of materials science; Scott White, professor of aerospace engineering, center; and Jeffrey Moore, professor of chemistry, have collaborated again. The inventors of self-healing plastic have come up with another invention: a new way of doing chemistry. Photo by L. Brian Stauffer.Nancy Sottos, professor of materials science; Scott White, professor of aerospace engineering, center; and Jeffrey Moore, professor of chemistry, have collaborated again. The inventors of self-healing plastic have come up with another invention: a new way of doing chemistry. Photo by L. Brian Stauffer.
For most chemical reactions to proceed the reactants need to surmount an energy barrier. The energy required is usually provided as heat, light, pressure or electrical potential. Now mechanical force can be added to that list - to the surprise of many a chemist. A reaction can literally be given a shove. Graphic by Benjamin Grosser, Imaging Technology Group, Beckman InstituteFor most chemical reactions to proceed the reactants need to surmount an energy barrier. The energy required is usually provided as heat, light, pressure or electrical potential. Now mechanical force can be added to that list - to the surprise of many a chemist. A reaction can literally be given a shove. Graphic by Benjamin Grosser, Imaging Technology Group, Beckman Institute
Researchers at the University of Illinois at Urbana-Champaign have found a novel way to manipulate matter and drive chemical reactions along a desired direction. The new technique utilizes mechanical force to alter the course of chemical reactions and yield products not obtainable through conventional conditions.

Potential applications include materials that more readily repair themselves, or clearly indicate when they have been damaged.

“This is a fundamentally new way of doing chemistry,” said Jeffrey Moore, a William H. and Janet Lycan Professor of Chemistry at Illinois and corresponding author of a paper that describes the technique in the March 22 issue of the journal Nature.

“By harnessing mechanical energy, we can go into molecules and pull on specific bonds to drive desired reactions,” said Moore, who also is a researcher at the Frederick Seitz Materials Laboratory on campus and at the university’s Beckman Institute for Advanced Science and Technology.

The directionally specific nature of mechanical force makes this approach to reaction control fundamentally different from the usual chemical and physical constraints

To demonstrate the technique, Moore and colleagues placed a mechanically active molecule – called a mechanophore – at the center of a long polymer chain. The polymer chain was then stretched in opposite directions by a flow field created by the collapse of cavitating bubbles produced by ultrasound, subjecting the mechanophore to a mechanical tug of war.

“We created a situation where a chemical reaction could go down one of two pathways,” Moore said. “By applying force to the mechanophore, we could bias which of those pathways the reaction chose to follow.”

One potential application of the technique is as a trigger to divert mechanical energy stored in stressed polymers into chemical pathways such as self-healing reactions.

In the original self-healing concept, microcapsules of healing agent are ruptured when a crack forms in the material. Capillary action then transports the healing agent to the crack, where it mixes with a chemical catalyst, and polymerization takes place.

With new mechanical triggers, however, mechanical energy would initiate the polymerization directly, thereby skipping many steps. The cross-linking of neighboring chains would prevent further propagation of a crack and avoid additional damage.

“We have demonstrated that it is now possible to use mechanical force to steer chemical reactions along pathways that are unattainable by conventional means,” Moore said. “We look forward to developing additional mechanophores whose chemical reactivity will be activated by external force.”

The other authors of the paper besides Moore are graduate student and lead author Charles Hickenboth, aerospace engineering professor Scott White, materials science and engineering professor Nancy Sottos, and research chemists Scott Wilson and Jerome Baudry. White, Sottos and Moore co-invented self-healing plastic.

The work was supported by the U.S. Air Force Office of Scientific Research and the Petroleum Research Fund.

Editor’s note: To reach Jeffrey Moore, call 217-244-4024; e-mail: jsmoore@uiuc.edu.

James E. Kloeppel, Physical Sciences Editor 217-244-1073 kloeppel@uiuc.edu

News Bureau, University of Illinois at Urbana-Champaign 807 South Wright Street, Suite 520 East, Champaign, Illinois 61820-6261 Telephone 217-333-1085, Fax 217-244-0161, E-mail news@uiuc.edu

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Thursday, March 22, 2007

Life cycle assessment essential to nanotech commercial development

Life cycle assessment essential to nanotech commercial development, Current methods adequate but toxicity data lacking

WASHINGTON, DC—Life cycle assessment (LCA) —a cradle-to-grave look at the health and environmental impact of a material, chemical, or product—is an essential tool for ensuring the safe, responsible, and sustainable commercialization of nanotechnology, U.S. and European experts conclude in a new report issued today.

Nanotechnology and Life Cycle Assessment: A Systems Approach to Nanotechnology and the Environment.With the number of nanotechnology-enabled products entering the market expected to grow dramatically—from $30 billion in 2005 to $2.6 trillion in global manufactured goods using nanotechnology by 2014—“numerous uncertainties exist regarding possible impacts on the environment and human health,” the international authors observe in (Download or oper in PDF fornat 1.2 MB) Nanotechnology and Life Cycle Assessment: A Systems Approach to Nanotechnology and the Environment.
According to the report, wisely implemented assessment tools such as LCA can help corporations and researchers determine likely environmental impacts at various stages in a new nanotechnology product’s life cycle. It also enables governments, industry and consumers to compare the environmental performance of a novel nanotech product with that of conventional products already on the market.

Based on discussions among 27 international nanotechnology and LCA experts at a two-day workshop held in October 2006, the report is being simultaneously released by the European Commission (EC) and the Project on Emerging Nanotechnologies, an initiative of the Woodrow Wilson International Center for Scholars and The Pew Charitable Trusts. The workshop was organized by the Project in cooperation with the EC, with assistance from the U.S. Environmental Protection Agency’s Office of Research & Development and International Society for Industrial Ecology. Barbara Karn, Project on Emerging Nanotechnologies visiting scientist, and Maria Pilar Aguar, from the EC’s Research Directorate-General (DG RTD), planned and organized the workshop.

The report concludes that the existing International Organization for Standardization (ISO) and other widely used frameworks for LCA are fully applicable to nanomaterials and nanoproducts.

However, according to the report, the specificity of LCA results for nanotechnology products will be limited by the “lack of data and understanding” in areas central to the accurate assessment of the environmental, human health, and safety effects of a particular nanomaterial or process.

“The lack of toxicity data specific to nanomaterials is a repeating theme in this and in other studies related to nanotech environmental, health, and safety concerns,” says Andrew Maynard, chief scientist for the Project on Emerging Nanotechnologies. “Nanotechnology is no longer a scientific curiosity. Its products are in the workplace, the environment, and home. But if people are to realize nanotechnology’s benefits—in electronics, medicine, sustainable energy, and better materials for building, clothing and packaging—the federal government needs an effective risk research strategy and sufficient funding in agencies responsible for oversight to do the job.”

“The report calls for international cooperation and coordination—among governments, university researchers, corporations, and consumer and other groups—to help address critical data needs,” according to Project visiting scientist Barbara Karn. “It also highlights the need for nano-specific protocols and practical methodologies for toxicology studies, fate and transport studies, and scaling approaches.”

Despite incomplete information, according to the report, LCA can be useful now, as long as uncertainties and data gaps are clearly stated. Results can help to focus attention on high-priority products and issues with the aim of eliminating critical unknowns and encouraging life-cycle thinking during the first wave of nanotechnology innovation.

“It is important that nanotechnology, which has the potential to improve the quality of life in all parts of the world, is developed in a responsible way. This includes conducting the research and development needed to take into account the impact of nanomaterials and products throughout their whole life cycle,” noted Renzo Tomellini, head of the Nano- and Converging Sciences and Technologies Unit in the EC’s DG RTD and chair of the European Commission Interservice Group on Nanotechnology. “The European Commission is committed to working together with international partners to ensure that this critical work takes place. This report is a useful step toward fulfilling that goal.”

The report is also available online at cordis.europa.eu/nanotechnology

Contact: Julia Moore julia.moore@wilsoncenter.org 202-691-4025 Project on Emerging Nanotechnologies

About Nanotechnology - Nanotechnology is the ability to measure, see, manipulate and manufacture things usually between 1 and 100 nanometers. A nanometer is one billionth of a meter; a human hair is roughly 100,000 nanometers wide. More than $30 billion in products incorporating nanotechnology were sold globally in 2005. By 2014, Lux Research estimates this figure will grow to $2.6 trillion.
The Project on Emerging Nanotechnologies is an initiative launched by the Woodrow Wilson International Center for Scholars and The Pew Charitable Trusts in 2005. It is dedicated to helping business, government and the public anticipate and manage possible health and environmental implications of nanotechnology.

The Pew Charitable Trusts is a national charitable organization serving the public interest by informing the public, advancing policy solutions and supporting civic life. Based in Philadelphia, with an office in Washington, D.C., the Trusts will invest $248 million in fiscal year 2007 to provide organizations with fact-based research and practical solutions for challenging issues.

The Woodrow Wilson International Center for Scholars is the living, national memorial to President Wilson established by Congress in 1968 and headquartered in Washington, D.C. The Center establishes and maintains a neutral forum for free, open, and informed dialogue. It is a nonpartisan institution, supported by public and private funds and engaged in the study of national and international affairs

Contact: Sharon McCarterPhone: (202) 691-4016 sharon.mccarter@wilsoncenter.org

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Wednesday, March 21, 2007

Nanotechnology the secret for next-generation LEDs

ORNL helps develop next-generation LEDs

OAK RIDGE, Tenn., March 19, 2007 — Nanotechnology may unlock the secret for creating highly efficient next-generation LED lighting systems, and exploring its potential is the aim of several projects centered at Oak Ridge National Laboratory.

Seen everywhere today from traffic signals, taillights and cell phone displays to stadium JumboTrons, light emitting diodes fluoresce as electrical current passes through them. The most developed LED technology is based on crystals, typically made from indium gallium nitride. However, researchers at ORNL's Center for Nanophase Materials Sciences and the University of Tennessee are working to develop technology that will improve a new generation of LED devices composed of thin films of polymers or organic molecules.

These organic LEDs are designed to be formed into thin, flexible sheets that hold promise for a new generation of lighting fixtures and flexible electronics displays. Currently applications of organic LEDs, or OLEDs, are limited to small-screen devices such as cell phones, personal digital assistants and digital cameras; however it is hoped that someday large displays and lighting fixtures can be produced using low-cost manufacturing processes.

At ORNL, researchers are developing electrodes composed of carbon nanotubes and magnetic nanowires to enhance the light emission from polymer-based OLEDs. In early tests, carbon nanotubes improved the electroluminescence efficiency of polymer OLEDs by a factor of four and reduced the energy required to operate them. Magnetic nanowires and dots have been shown to help control the spin of electrons injected into the OLEDs to further improve the efficiency and reliability of the devices. A third aspect of the research focuses on creation and chemical processing of the nanotubes themselves. Researchers at ORNL use a technique called laser vaporization produces purer nanotubes with fewer defects than other fabrication techniques.

With assistance of a $600,000 grant from the Department of Energy's Office of Energy Efficiency and Renewable Energy, the ORNL/UT team hopes to merge the science and new materials research into a new technology for practical OLED devices that consumes less than half the power of today's technology and opens the door for their practical use in household lighting.

"The real, long-term solution to making a more efficient device may be found in nanoscience," said David Geohegan, an ORNL researcher who is leading the OLED effort. "Over the next year we hope to learn why nanomaterials enhance these devices. I think someday we will see OLEDs everywhere, from more durable touch-screen displays to electronic newspapers that we can roll up and carry easily to even larger wall displays for home entertainment or lighting."

The Center for Nanophase Materials Sciences at ORNL is one of five Department of Energy-funded user laboratories set up to allow visiting scientists from universities and industry to use the facilities' world-class instruments and experts to fabricate, test and characterize a variety of new materials at a molecular level.

Researchers on this project are also working with Battelle Memorial Institute as part of the Battelle Nanotechnology Innovation Alliance to further develop nanomaterials for numerous other applications not only in solid-state lighting technology but also numerous other fields.

UT-Battelle manages Oak Ridge National Laboratory for the Department of Energy.

Media Contact: Larisa M. Brass Communications and External Relations 865.574.4163

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Tuesday, March 20, 2007

Biologically Assembled Quantum Electronic Systems

6 universities collaborate to study biologically assembled quantum electronic systems, US Department of Defense awards $6M for joint research effort

Caption: UCLA Engineering's Kang Wang in his lab. Credit: UCLA Engineering, Usage Restrictions: Permission to use photo is granted to all news media organizations in context with story or caption explaining grant.The U.S. Department of Defense is awarding a team of nine professors from six universities $6 million over five years to exploit precise biological assembly for the study of quantum physics in nanoparticle arrays. High Resolution Image
This research will help to produce a fundamental understanding of quantum electronic systems, which could impact the way future electronics are created.

The UCLA Henry Samueli School of Engineering and Applied Science is teaming up with leading researchers at the University of Minnesota, New York University, the University of Texas at Austin, the University of Pennsylvania and Columbia University to develop biological strategies combining DNA, proteins, and peptides with chemical synthesis techniques to construct arrays of nanoparticles. (A nanoparticle array consists of metal particles with a diameter of 0.5-5 nanometers. The interactions among them produce highly correlated behaviors.)

Joining biological to man-made materials is the first step to a whole new materials assembly technique that will operate on the nanoscale. Interactions between precisely arranged metallic nanoparticles could lead to new physics discoveries – as well as to new mechanisms for computing, signal processing, and sensing.

"Highly interacting and correlated systems will be extremely important in creating future robust nanoscale electronic devices," said UCLA Engineering's Kang Wang, one of the team members involved in the research.

Basic studies of such nanoparticle arrays have in the past been hampered by the need to fabricate test structures with extreme control and precision. Most semi conducting devices, such as computer chips, are made from the top down. Patterns are imposed on the material and etched into it. The biological assembly technique aims at building from the bottom up, atom by atom or molecule by molecule.

"By exploiting biology to precisely control size, spacing, composition, and coupling in the arrays, we will be able to examine the effects of electronic, magnetic, and optical interactions at much smaller dimensions than in the past. This will open a wide range of unbroken ground for exploring new physics," said electrical and computer engineering professor Richard A. Kiehl of the University of Minnesota, who is leading the effort. Kiehl has a wide-ranging experience in investigating the potential of novel fabrication techniques, physical structures, and architectures for electronics.

The team members from the six universities include two professors from the UCLA Henry Samueli School of Engineering and Applied Science, Yu Huang (materials science) and Kang L. Wang (electrical engineering), as well as UCLA professor Todd O. Yeates (biochemistry); New York University professors Andrew D. Kent (physics) and Nadrian C. Seeman (chemistry); University of Minnesota professor Richard A. Kiehl (electrical and computer engineering); University of Texas at Austin professor Allan H. MacDonald (physics); University of Pennsylvania professor Christopher B. Murray (chemistry); and Columbia University professor Colin Nuckolls (chemistry).

Kiehl and Seeman have previously collaborated in the first demonstration of metallic nanoparticle assembly by DNA scaffolding, which will be central to this project. Seeman will exploit DNA nanotechnology to construct 2D and 3D scaffolding for the nanoparticle arrays, while Huang and Yeates will use peptides and proteins to make nanoparticle clusters for assembly onto the scaffolding. Murray and Nuckolls will synthesize metallic and magnetic nanoparticles with organic shells that will self-assemble to the scaffolding and control the interparticle coupling. Kent, Kiehl, and Wang will carry out experiments to characterize the electronic, magnetic, and optical properties of the arrays. Kiehl and Wang also have been collaborating for the past four years at the Center on Functional Engineered Nano Architectonics (FENA), a multi-university center headquartered at the UCLA Henry Samueli School of Engineering and Applied Science. MacDonald will provide theoretical guidance for the studies and analysis of the experimental results.

"While our goal is to use biology to construct a 'nanoscale test vehicle' for the systematic study of basic physics today, this work could lead to a practical biological route for the assembly of quantum electronic systems in the future," said Kiehl.

Quantum electronic systems are strongly influenced by interactions both within and between nanoparticles, and hence are extremely sensitive to the quality and dimensions of the structure. ###

Ranked among the top 10 engineering schools among public universities nationwide, the UCLA Henry Samueli School of Engineering and Applied Science is home to seven multimillion dollar interdisciplinary research centers in space exploration, wireless sensor systems, nanomanufacturing and defense technologies, funded by top national and professional agencies.

The award was given by the Army Research Office and is one of 36 awards selected for funding under the highly competitive Department of Defense Multidisciplinary University Research Initiative (MURI). The DoD news release may be viewed at defenselink.mil/releases/ .

About the UCLA Henry Samueli School of Engineering and Applied Science Established in 1945, the UCLA Henry Samueli School of Engineering and Applied Science offers 28 academic and professional degree programs, including an interdepartmental graduate degree program in biomedical engineering. For more information, visit http://www.engineer.ucla.edu/.

Contact: Melissa Abraham mabraham@support.ucla.edu 310-206-0540 University of California - Los Angeles

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