Do You Know Nano?

The Project on Emerging Nanotechnologies is a fast-paced science policy group within the Woodrow Wilson International Center for Scholars in Washington, DC. The Project serves as a neutral, nonpartisan forum for study, discussion, and debate of the issues surrounding nanotechnology policy. The Project has become a reference point for information and analysis of these issues as it strives to bring the voices of policymakers, industry, and academia together to promote a fair and rational consideration of the risks and benefits of nanotechnology.

The Project is seeking qualified interns for Fall/Winter 2009. The Project’s internship program provides graduate and undergraduate level students an exciting opportunity to work the world of science policy and learn about the rapidly expanding field of nanotechnology. Past interns have worked with former officials of the EPA, FDA, and NIOSH on analyses of research and regulatory priorities at those agencies, and helped coordinate focus groups and national polls, prepare congressional testimony, compile the largest and most comprehensive database available of consumer products containing nanotechnologies—and worked on many other projects. For more information on the internship program at the Project on Emerging Nanotechnologies, please see the Intern Position Announcement. Questions? Email nano@wilsoncenter.org with Intern in the subject line. Applications are due by August 22, 2009.

findNano App Puts Nanotech in Your Pocket

WASHINGTON – The Project on Emerging Nanotechnologies (PEN) has developed findNano, an application for Apple’s iPhone and iPod Touch that lets users discover and determine whether consumer products are nanotechnology-enabled. Nanotechnology, the emerging technology of using materials by engineering them at an incredibly small scale, has applications ranging from consumer electronics to improved drug delivery systems.

findNano allows users to browse an inventory of more than 1,000 nanotechnology-enabled consumer products, from sporting goods to food products and electronics to toys, using the iPhone and iPod Touch. Using the built-in camera, iPhone users can even submit new nanotech products to be included in future inventory updates.

The new application makes PEN’s unique Consumer Products Inventory more accessible for today’s consumers. The inventory, which was launched in 2006, is the leading source of information on manufacturer-identified nanotechnology consumer products around the world.

“The Consumer Products Inventory provides valuable insight into the world of nanotech consumer products, and now it’s even easier to access because of findNano,” says PEN Research Associate Patrick Polischuk. “This innovative tool satisfies the needs of citizen scientists, tech-savvy consumers, and those who are merely curious about whether products contain nanomaterials.”

The number of nanotech products in the inventory has risen from approximately 200 in 2006 to more than 1,000 today. But this is most likely an underestimate of the number of products using nanotechnology available worldwide. To help develop better estimates of the number of nano-based products in commerce, the iPhone app allows users to submit information on new products, including product name and where the product can be purchased.

Using findNano, users can take or select a photo of a possible nanotech product and submit it for inclusion in the PEN inventory. This feature will help consumers, researchers, and policymakers determine how—and where—nanotechnologies are entering the marketplace.

findNano is available as a free download for the iPhone and iPod Touch, and can be found in the iTunes App Store or at nanotechproject.org/iphone.

Reinventing Technology Assessment for the 21st Century

WASHINGTON—A new report from the Science and Technology Innovation Program at the Woodrow Wilson International Center for Scholars defines the criteria for a new technology assessment function in the United States. The report, Reinventing Technology Assessment: A 21st Century Model, emphasizes the need to incorporate citizen-participation methods to complement expert analysis. Government policymakers, businesses, non-governmental organizations, and citizens need such analysis to capably navigate the technology-intensive world in which we now live.

The U.S. Congress set a global precedent in 1972 when it created an Office of Technology Assessment (OTA), but then reversed course in 1995 by shutting down the OTA. In the meantime, 18 European Technology Assessment agencies are flourishing and have pioneered important new methods, including Participatory Technology Assessment (pTA). By educating and engaging laypeople, pTA is unique in enabling decision-makers to learn their constituents’ informed views regarding emerging developments in science and technology. pTA also deepens the social and ethical analysis of technology. European pTA methods have been adapted, tested, and proven in the U.S. at least 16 times by university-based groups and independent nonprofit organizations.

“We style ourselves as living in a ‘technological society’ and an ‘information age,’” notes report author Dr. Richard Sclove, “yet we lack adequate information about – of all things! – the broad implications of science and technology.”

As the pace of technological change quickens and the Obama Administration moves forward on its Open Government Initiative, the time is ripe to institutionalize a robust national TA capability incorporating both expert and participatory TA methods. The Internet and social networking capacities make it possible to organize such an endeavor on a distributed, agile and open basis, harnessing collaborative efficiencies and supporting broad public engagement.

“In the 15 years since OTA was closed, TA has progressed significantly in Europe. It is time for the U.S. to institutionalize a serious, continuous and nonpartisan capability to assess the broad social, ethical, legal, and economic impacts of emerging science and technology in areas such as nanotechnology, biotechnology, and earth systems engineering,” said David Rejeski, who directs the Wilson Center program.

In the report, Dr. Sclove recommends creating a nationwide Expert & Citizen Assessment of Science & Technology (ECAST) network that will combine the skills of nonpartisan policy research organizations with the research strengths of universities and the public outreach and education capabilities of science museums. Founding partners in ECAST include the Science and Technology Innovation Program at the Wilson Center,, the Boston Museum of Science, Arizona State University, ScienceCheerleader, and the Loka Institute.

Report author Richard Sclove, Ph.D. is founder and senior fellow of the Loka Institute, a nonprofit organization dedicated to making science and technology responsive to democratically decided priorities.

The report can be downloaded at http://www.wilsoncenter.org/techassessment

Nanotech-enabled Consumer Products Top the 1,000 Mark

Over 1,000 nanotechnology-enabled products have been made available to consumers around the world, according to the Project on Emerging Nanotechnologies (PEN). The most recent update to the group’s three-and-a-half-year-old inventory reflects the increasing use of the tiny particles in everything from conventional products like non-stick cookware and lighter, stronger tennis racquets, to more unique items such as wearable sensors that monitor posture.

“The use of nanotechnology in consumer products continues to grow rapidly,” says PEN Director David Rejeski. “When we launched the inventory in March 2006 we only had 212 products. If the introduction of new products continues at the present rate, the number of products listed in the inventory will reach close to 1,600 within the next two years. This will provide significant oversight challenges for agencies like the Food and Drug Administration and Consumer Product Safety Commission, which often lack any mechanisms to identify nanotech products before they enter the marketplace.”

Health and fitness items continue to dominate the PEN inventory, representing 60 percent of products listed. More products are based on nanoscale silver—used for its antimicrobial properties—than any other nanomaterial; 259 products (26 percent of the inventory) use silver nanoparticles. The updated inventory represents products from over 24 countries, including the US, China, Canada, and Germany. This update also identifies products that were previously available, but for which there is no current information.

The release of the updated inventory coincides with a public hearing on the agenda and priorities of the Consumer Product Safety Commission (CPSC) where project director David Rejeski testified. The CPSC, with a staff of fewer than 400 employees, oversees the safety of 15,000 types of consumer products.

Andrew Maynard, chief science advisor for PEN, noted that “the CPSC deserves credit for focusing on nanotechnologies. The resources available to the agency to address health and safety issues are negligible compared to the over $1.5 billion federal investment in nanotechnology research and development.”

The inventory is available at http://www.nanotechproject.org/inventories/consumer/

The PEN consumer products inventory includes products that have been identified by their manufacturer or a credible source as being nanotechnology-based. This update identifies products that were previously sold, but which may no longer be available. It remains the most comprehensive and widely used source of information on nanotechnology-enabled consumer products in the world.

Download project director David Rejeski’s testimony before the CPSC here.

nanoscience and nanotechnology

Nanoscience, nanotechnology, or nanotech, are all used to describe the same dynamic new field of applied science. Simply put, nanotechnology is the study and development of components measuring 100 nanometers (one billionth of a meter) or less. At these dimensions, matter begins to exhibit different characteristics. Aluminum explodes on contact with the air. Carbon can become a one-dimensional material, and conduct electricity better than copper.

The concept of nanoscience was first broached by Dr. Richard Feynman, a Nobel Prize-winning physicist who helped develop the atom bomb and did much to make physics popularly comprehensible through a series of lectures and books. In a 1959 speech that speculated on the immense potential of a conflux between biology and manufacturing, Dr. Feynman described the intricacy with which biological cells manufacture substances in natural bodies, and challenged his audience to “consider the possibility that we, too, can make a thing very small, which does what we want—that we can manufacture an object that maneuvers at that level.”

The actual word “nanotechnology” was coined by Tokyo Science University Professor Norio Taniguchi in 1974, to describe the manufacture of materials with at the level of a billionth of a meter. The term was popularized by controversial researcher Dr. K. Eric Drexler in a book that proposed the idea of manufacturing an “assembler” of nanoscale matter.

The applications of nanotechnology have been both expansive and prosaic. The implications, however, are still under scrutiny. While it is exciting to see products of startling efficiency and low cost result from this technology, and to speculate on the near possibility of cures for cancer, further research is essential to development this emergent technology in its most beneficial form possible.

Biotechnology Companies

Biotechnology is a practice as simple, and as ancient, as brewing beer or making cheese. In a practical sense, biotechnology is nothing more than humans putting to use the natural activity of microorganisms. But in the last twenty years, biotechnology has become one of the world’s most rapidly growing industries, as researchers dig out the ever unfolding capabilities of a single cell.

The preponderance of biotechnology companies are focused on medical science. These corporations not only produce medication, but also do heavy research into the environmental and genetic factors for disease. Their focus on disease prevention powers them forward in the medical business, and the top biotechnology companies may well outpace their pharmaceutical counterparts in as little as five years.

Biotechnology companies also plays a part in environmental science. By manipulating materials at the cellular level, solar energy companies produce receptors that will in time eliminate the need for fuel-based electricity. Similarly, genetic engineering has produced oil-utilizing microorganisms that can be spread over the surface of oceanic oil spills, simplifying the clean-up and the restoration of the ecosystem. Biofertilizers and disease-resistant plants are being developed to replace the toxic chemical pesticides used in conventional agriculture.

The intricacy of cellular function also serves as a model for improving existing industrial processes. Biotechnology has been the key to streamlining chemical manufacturing, decreasing water usage and waste generation in industry, and finding uses for traditional industrial waste.

Nanotechnology in Medicine

Nanoscience has, since its conception, been intertwined with medical research. The science is based on the replication and substance manufacturing of cells. Nanotechnology began as an endeavor to mimic the cell’s amazing self-sufficiency, and has since become an industry that strives to improve existing products in every sector through the manipulation of matter on the cellular level. This is most poignantly seen in the application of nanotechnology back to the medical field, where it began.

In one such application, nanoparticles of substances such as heat, light, or drugs, are engineered to have an attraction to diseased cells. This allows for direct treatment of diseased cells with minimal damage to healthy cells.

There is ongoing research, testing the efficacy of delivering chemotherapy drugs via nanoparticles directly to cancer cells.

Another example is the activation of nanoparticles by x-rays, to generate cancer-destroying electrons. This application would replace radiation therapy and circumvent its disastrous effects on the body’s healthy tissue.

Other developments include the use of nanoparticles to stimulate the production of cartilage in damaged joints, or the immune response against viruses.

Disease prevention is another important use of nanotechnology in medicine. Quantum Dots, an application still in its testing phase, may be used for finding cancerous tumors and for performing diagnostic tests. Nanocrystalline silver is one of the earliest forms of medical nanotechnology, used as an antimicrobial wound treatment.

Finally, nanotechnology is making vast improvements in the tools that physicians and medical scientists depend upon. From high-powered microscopes and imaging technology, to refined surgery implements, nanotechnology makes for cleaner, faster and more precise medicine.

Nanotechnology Investment

“Long-term, nanotech has the potential to be as significant as the steam engine, the transistor and the Internet.” (Tom Kalil, former Deputy Assistant to President Clinton for Technology and Economic Policy)

Since its conceptual debut in 1959, nanotechnology has promised an amazing wealth of potential. The possibilities it suggests for uses as noble as space travel, to as mundane as car manufacturing, make it a front-running candidate for public and private investment.

The practical similarities of nanotechnology to biotechnology mirror their commercial paths, as nanotechnology allows similar strategies toward commercialization and investment opportunities.

In only the last ten years, initiatives such as the National Nanotechnology Initiative and the European Union Framework for Nanotechnology set the precedent in the western world for government funding in nanotechnology research. According to a study completed by Lux Research in 2004, the United States is putting more money into nanotechnology than any other country.

However, Asian companies are close behind, with such countries as Taiwan and South Korea bending their efforts toward the development of actual products improved by nanotechnology, such as magnetoresistive RAM, and display consoles for computer and television lighted by carbon nanotubes. Indeed, nanotechnology has launched a new friendly competition among nations, similar to the international space race of the middle 20th century.

Investing in Nanotechnology

“Long-term, nanotech has the potential to be as significant as the steam engine, the transistor and the Internet.” (Tom Kalil, former Deputy Assistant to President Clinton for Technology and Economic Policy)

Since its conceptual debut in 1959, nanotechnology has promised an staggering wealth of potential. The possibilities it suggests for uses as noble as space travel, to as mundane as car manufacturing, make it a front-running candidate for investment.

There are a variety of ways to invest in nanotechnology including stocks of individual research companies, mutual funds weighted toward nanotechnology, and more recently an ETF which also seeks to track the value of the nanotechnology sector. Each of these investment vehicles is different and you are encouraged to research them to find the one that best fits your strategy.

The exciting trajectory and the spectrum of possibilities for nanotechnology has inspired a great number of small companies, who capitalize on the United States government’s interest in leading the world in this field. Additionally, many large companies are spawning smaller ones in an effort to focus their expertise onto manageable projects.

In itself, nanotechnology is an intriguing opportunity for the investor. However, But its particular incarnations require thoughtful research into not only their potential, but also for the implications of their work.

New Biotech Companies

One of the hard hits of the recent economic recession has been the slow-down of private funding for biotechnology research and development. With a general haze of uncertainty hovering in the economic climate, comes an apprehensive attitude toward emergent industry. As consumers tighten their hold on limited resources, they adopt a wary approach toward what they view as unproven technology. And as the consumer goes, so also goes the venture capitalist. Consequently, sources of funding, especially for start-up and early-stage companies, have grown scarce in recent years.

Companies that persist in the face of this economic adversity have proven their creativity in avoiding the need for large amounts of capital. They have sought out standardized form licensing, with pre-established economic terms, to reduce the obstacles between technological discovery and the launch of research. Additionally, established biotech companies are beginning to partner with fledgling developers, licensing out a concept for development by the smaller company, which allows both companies to benefit from the resultant technology.

Finally, companies have focused on bringing prototypes of their technology only to the stage where it will attract the interest of large investors. This involves focusing efforts on the development of a specific, marketable product. The result of this focused development is exemplified in new biotech companies such as Allylix, a tiny firm in San Diego, CA that engineers fragrances at the molecular level to produce sought-after tastes and fragrances for beverages and perfumes at a fraction of the cost. The future will reveal companies, which will focus on treatments for cancer, infections, autoimmune diseases and new techniques in immunogen development.

Innovative solutions such as these are a benefit to the industry as a whole, as biotech companies set themselves to doing one thing well, rather than spreading their efforts unprofitably wide.

Biotech Companies

In the last twenty years, biotechnology has become one of the world’s most rapidly growing industries, as researchers dig out the ever unfolding capabilities of a single cell.

The preponderance of biotechnology companies are focused on medical science. Corporations such as
Amgen, Gilead Sciences, and Merck & Co. are the leaders in development of medicine production, refining synthetic therapeutics to greater effectiveness and reduced cost.

Other biotech companies, such as Geron and Heal Corporation, are primarily dedicated to investigating the environmental and genetic factors for disease.

It has been speculated that the top biotechnology companies may well outpace their pharmaceutical counterparts in as little as five years.

Biotech companies also play a part in repairing the environment and improving existing industrial processes. With innovations in solar energy, chemical manufacturing, agriculture, and waste repurposing, biotech companies put the intricacies of the natural cell to astonishing practical use.

Nanotechnology

Nanoscience, nanotechnology, or nanotech, are all used to describe the same dynamic new field of applied science. Simply put, nanotechnology is the study and development of components measuring 100 nanometers (one billionth of a meter) or less. At these dimensions, matter begins to exhibit different characteristics. Aluminum explodes on contact with the air. Carbon can become a one-dimensional material, and conduct electricity better than copper.

The applications of nanotechnology have been both expansive and prosaic. Nanocrystal quantum dots are being developed to provide efficient emission of laser light, which could pave the way for startling efficiency of computing, communications and remote sensing. One of the first commerical practices of nanotechnology was the development of nanocatalysts for important chemical reactions. Nanocatalysts are being developed with 100% selectivity, extremely high activity, low energy consumption, and long lifetimes, to replace expensive and frangible catalysts and speed the forward motion of scientific research.

In the more prosaic realm, nanotechnology has been applied to the automotive industry to produce cars with improved engine efficiency, lighter but stronger body materials, reduced environmental impact, even self-repairing materials for better economies.

The result of nanotechnology is already apparent on store shelves–we already see pants, shirts and bedsheets with nanostructure textile coatings that make them wrinkle-proof or stain-repellent.

Nanotechnology Companies Stock

The emergent industry of nanotechnology has grown exponentially in the past ten years, and the stock market has struggled to keep up. As nanotech companies proliferate, there is some confusion over what constitutes a nanotech stock.

For example, the ISE-CCM Nanotechnology Index defines a nanotech stock like this:

“Companies involved in the science and technology of building electronic circuits and devices from single atoms and molecules. Applications involve the intended ability to manipulate materials to fundamentally improve processes, materials, and devices on an ‘atomic’ scale.”
Meanwhile, Merrill Lynch states in its documentation:

“Our new criteria for inclusion in the index is companies that indicate in public documents that nanotechnology initiatives represent a significant component of their future business strategy. We believe this definition, although still subjective, is more objective than our previous criteria that companies must have a significant percentage of future profits tied to nanotech.”
The problem with any attempt at defining a nanotech stock is that one must start with defining the nanotech industry. Nanoscience affects many scientific fields, industries, markets and products.
A “pure” nanotech stock for instance would be a company that manufactures nanoparticles, and nothing else. But as nanotechnology is an applied science, the plurality of nanotech companies have a particular product in development toward which their technology is directed. For instance, chemical giants BASF or DuPont produce nanomaterials–should they not as easily qualify as a nanotech stock, as a nanobiotech company like Geron or Amgen? Or companies that take “pure” nanomaterials and use them to make parts for end products that are not nanotech-specific, such as stain-resistant fabric or enhanced computer displays.

In the end, it must be decided what percentage of a company’s revenues should come from nanotech before they become a nanotech stock?

The volatile state of the three major exchange-quoted nanotechnology stock indices reflects this uncertainty.
Starting in late 2005, all three would have outperformed the Dow Jones Industrial Average. But in June of 2006, stocks dropped by 5-10%, with no clear reason for the sudden reversal.

As might be expected by a new industry whose primary funding is directed into research and prototype development, it is best to look into nanotech stock as a long-term investment. Growth over the next several years is likely, but there are equally likely to be bumps along the way.

Nanotechnology Companies

Simply put, nanotechnology is the study and development of components measuring 100 nanometers (one billionth of a meter) or less. At these dimensions, matter begins to exhibit different characteristics. Aluminum explodes on contact with the air. Carbon can become a one-dimensional material, and conduct electricity better than copper.

In the past ten years, the applied sciences field has been proliferated with companies devoted to the research of nanotechnology’s potential, and the development of products that showcase its capabilities to improve upon natural matter. Large chemical and manufacturing concerns have established nanotechnology arms to refine their production and remain competitive in their market. Smaller entities, with the eager help of public funding, have proven themselves strong with focused, product-specific innovations that prove nanotechnology’s value under the scrutiny of investors.

Nonetheless, it should be unsurprising that the stock market’s reflection of the nanotech industry should be unsteady. Between the relative novelty of the nanotech field, the number of start-ups represented among nanotech companies, and the nearly worldwide economic recession, a fair amount of ebb and flow in the longevity of individual companies is a reasonable expectation.

But with so much still to be grasped, and with such staggering innovations as nanotech companies have already generated in common products–self-regenerating car paint, stain-resistant fabrics, chemotherapy treatments that target diseased cells in the human body–it is best to look into nanotech companies as a long-term investment in an undeniably burgeoning field.

Researchers create new high-performance fiber

Working in a multidisciplinary team that includes groups from other universities and the MER Corporation, Horacio Espinosa, James N. and Nancy J. Farley Professor in Manufacturing & Entrepreneurship at the McCormick School of Engineering and Applied Science, and his group have created a high performance fiber from carbon nanotubes and a polymer that is remarkably tough, strong, and resistant to failure. Using state-of-the-art in-situ electron microscopy testing methods, the group was able to test and examine the fibers at many different scales — from the nano scale up to the macro scale — which helped them understand just exactly how tiny interactions affect the material's performance. Their results were recently published in the journal ACS Nano.

"We want to create new-generation fibers that exhibit both superior strength and toughness," said Espinosa said. "A big issue in engineering fibers is that they are either strong or ductile — we want a fiber that is both. The fibers we fabricated show very high ductility and a very high toughness. They can absorb and dissipate large amounts of energy before failure. We also observed that the strength of the material stays very, very high, which has not been shown before. These fibers can be used for a wide variety of defense and aerospace applications."

The project is part of the Department of Defense's Multidisciplinary University Research Initiative (MURI) program, which supports research by teams of investigators that intersect more than one traditional science and engineering discipline. Espinosa and his collaborators received $7.5 million from the U.S. Army Research Office for the study of disruptive fibers, which could be used in bulletproof vests, parachutes, or composite materials used in vehicles, airplanes and satellites.

To create the new fiber, researchers began with carbon nanotubes —cylindrical-shaped carbon molecules, which individually have one of the highest strengths of any material in nature. When you bundle nanotubes together, however, they lose their strength — the tubes start to laterally slip between each other.

Working with the MER Corporation and using the corporation's CVD reactor, the team added a polymer to the nanotubes to bind them together, and then spun the resulting material into yarns. Then they tested the strength and failure rates of the material using in-situ SEM testing, which uses a powerful microscope to observe the deformation of materials under a scanning electron beam. This technology, which has only been available in the past few years, allows researchers to have extremely high resolution images of materials as they deform and fail and allows researchers to study materials on several different scales. They can examine individual bundles of nanotubes and the fiber as a whole.

"We learned on multiple scales how this material functions," said Tobin Filleter, a postdoctoral researcher in Espinosa's group. "We're going to need to understand how molecules function at these nanometer scales to engineer stronger and tougher fibers in the future."

The result is a material that is tougher than Kevlar — meaning it has a higher ability to absorb energy without breaking. But Kevlar is still stronger — meaning it has a higher resistance to failure. Next, researchers hope to continue to study how to engineer the interactions between carbon nanotube bundles and between the nanotubes within the bundle itself.

"Carbon nanotubes, the nanoscale building blocks of the developed yarns, are still 50 times stronger than the material we created," said Mohammad Naraghi, a postdoctoral researcher in Espinosa's group. "If we can better engineer the interactions between bundles, we can make the material stronger."

The group is currently looking at techniques — like covalently crosslinking tubes within bundles using high-energy electron radiation – to help better engineer those interactions.

Filleter and Naraghi said this work wouldn't have been possible without the interdisciplinary team that includes merging academia with industry.

"To work in an environment where we can trade information back and forth is a unique opportunity that will push the technology farther," Naraghi said. "MER has given us a unique raw material and a commercial perspective on the project. In turn, we provide the fundamental scientific understanding."

NASA engineers develop 'blacker than black' nanotubes (w/ Video)

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Principal Investigator John Hagopian developed a new nanotech-based material that is 10 times more effective than black paint used by instrument developers to absorb stray light, which can contaminate scientific data. The sample on the left is black paint typically used to suppress errant light in instruments; the sample on the right is the new nanotube material. Credit: Chris Gunn/NASA

The nanotech-based material now being developed by a team of 10 technologists at the NASA Goddard Space Flight Center in Greenbelt, Md., is a thin coating of multi-walled carbon nanotubes — tiny hollow tubes made of pure carbon about 10,000 times thinner than a strand of human hair. Nanotubes have a multitude of potential uses, particularly in electronics and advanced materials due to their unique electrical properties and extraordinary strength. But in this application, NASA is interested in using the technology to help suppress errant light that has a funny way of ricocheting off instrument components and contaminating measurements.

Better than Paint

"This is a technology that offers a lot of payback," said engineer Leroy Sparr, who is assessing its effectiveness on the Ocean Radiometer for Carbon Assessment (ORCA), a next-generation instrument that is designed to measure marine photosynthesis. "It's about 10 times better than black paint" typically used by NASA instrument designers to suppress stray light, he said.

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Multi-walled carbon nanotubes are tiny hollow tubes made of pure carbon about 10,000 times thinner than a strand of human hair. NASA is investigating their use to help suppress errant light that ricochets off instrument components and contaminates measurements. Credit: NASA

The technology works because of its super-absorption abilities. The nanotubes themselves are packed vertically much like a shag rug. The tiny gaps between the tubes absorb 99.5 percent of the light that hits them. In other words, very few photons are reflected off the carbon-nanotube coating, which means that stray light cannot reflect off surfaces and interfere with the light that scientists actually want to measure. The human eye sees the material as black because only a small fraction of light reflects off the material.

The team began working on the technology in 2007. Unbeknownst to the group, the New York-based Rensselaer Polytechnic Institute also had initiated a similar effort and announced in 2008 that its researchers had developed the darkest carbon nanotube-based material ever made — more than three times darker than the previous record.

"Our material isn't quite as dark as theirs," said John Hagopian, the principal investigator leading the development team. "But what we're developing is 10 times blacker than current NASA paints that suppress system stray light. Furthermore, it will be robust for space applications," he said.

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NASA's Goddard Space Flight Center has a team of scientists testing micro and nanotechnology to use on spacecraft. The goal is to reduce the reflection off the surface of instruments satellites so that the data does not get polluted by the scattered light. The carbon nanotubes that the team grows have proven to be 10 times better than the NASA Z306 paint, currently used on spacecraft instruments.

That is an important distinction, said Carl Stahle, assistant chief of technology for Goddard's Instrument Systems and Technology Division. Not all technology can be used in space because of the harsh environmental conditions encountered there. "That's the real strength of this effort," Stahle said. "The group is finding ways to apply new technology and fly it on our instruments."

Big Breakthrough

The breakthrough was the discovery of a highly adhesive underlayer material upon which to grow the carbon nanotubes, which are just a few tens of nanometers in diameter. To grow carbon nanotubes, materials scientists typically apply a catalyst layer of iron to an underlayer on the silicon substrate. They then heat the material in an oven to about 750° C (1,382° F). While heating, the material is bathed in carbon-containing feedstock gas.

Stephanie Getty, the materials scientist on Hagopian's team, varied the underlayer as well as the thickness of the catalyst materials to create carbon nanotubes that not only absorb light, but also remain fixed to the material upon which they are grown. As a result, they are more durable and less likely to scratch off. The team also has grown durable nanotube coatings on titanium, a better structural material for space use. The team now is fine-tuning production techniques to assure consistent quality and light-suppression capabilities, Hagopian said.

New Capabilities Added

Should the team prove the material's suitability in space, the material would provide real benefits to instrument developers, Hagopian added.

Currently, instrument developers apply black paint to baffles and other components to reduce stray light. Because reflectance tests have shown the coating to be more effective than paint, instrument developers could grow the carbon nanotubes on the components themselves, thereby simplifying instrument designs because fewer baffles would be required. To accommodate larger components, the team now is installing a six-inch furnace to grow nanotubes on components measuring up to five inches in diameter. And under a NASA R&D award, the team also is developing a separate technique to create sheets of nanotubes that could be applied to larger, non-conforming surfaces.

In addition to simplifying instrument design, the technology would allow scientists to gather hard-to-obtain measurements because of limitations in existing light-suppression techniques or to gather information about objects in high-contrast areas, including planets in orbit around other stars, Hagopian said.

The ORCA team, which is fabricating and aligning an instrument prototype, is the first to actually apply and test the technology. The instrument is the front-runner for the proposed Aerosol/Cloud/Ecosystems (ACE) mission and requires robust light-suppression technologies because more than 90 percent of the light gathered by the instrument comes from the atmosphere. Therefore, the team is looking for a technique to suppress the light so that it doesn't contaminate the faint signal the team needs to retrieve.

"It's been an issue with all the (ocean sensors) we've flown so far," said ORCA Principal Investigator Chuck McClain.

Working with the ORCA team, Hagopian's group grew the coating on a slit, the conduit through which all light will pass on ORCA. "Having an efficient absorber is critical and the nanotubes could provide the solution," McClain said. "Right now, it looks promising," Sparr added. "If I can support them and they can continue advancing the technology so that it can be applied to other spacecraft components, it could be a very important development for NASA."

Goddard Chief Technologist Peter Hughes agrees, and, in fact, selected Hagopian and his team to receive his organization’s 2010 "Innovator of the Year" award. "Our job is to develop and advance new technology that will ultimately result in better scientific measurements. Goddard has a well-deserved reputation for creating technologies that enhance instrument performance because we are adept at quickly infusing emerging technology for specific spaceflight applications. John’s team demonstrated that key strength. And in doing so, he’s leading the way in NASA’s quest to bring about a new level of scientific discovery," Hughes said.

Light touch brightens nanotubes (w/ Video)

Single-walled carbon nanotubes treated with ozone incorporate oxygen atoms that shift and intensify the nanotubes' near-infrared fluorescence emission. The discovery by Rice University scientists should lead to new uses of nanotubes in biomedicine and materials science. (Credit: Bruce Weisman/Rice University)

The Rice lab of researcher Bruce Weisman, a pioneer in nanotube spectroscopy, found that adding tiny amounts of ozone to batches of single-walled carbon nanotubes and exposing them to light decorates all the nanotubes with oxygen atoms and systematically changes their near-infrared fluorescence.

Chemical reactions on nanotube surfaces generally kill their limited natural fluorescence, Weisman said. But the new process actually enhances the intensity and shifts the wavelength.

He expects the breakthrough, reported online in the journal Science, to expand opportunities for biological and material uses of nanotubes, from the ability to track them in single cells to novel lasers.

Best of all, the process of making these bright nanotubes is incredibly easy -- "simple enough for a physical chemist to do," said Weisman, a physical chemist himself.

He and primary author Saunab Ghosh, a graduate student in his lab, discovered that a light touch was key. "We're not the first people to study the effects of ozone reacting with nanotubes," Weisman said. "That's been done for a number of years.

"But all the prior researchers used a heavy hand, with a lot of ozone exposure. When you do that, you destroy the favorable optical characteristics of the nanotube. It basically turns off the fluorescence. In our work we only add about one oxygen atom for 2,000-3,000 carbon atoms, a very tiny fraction."

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Ghosh and Weisman started with a suspension of nanotubes in water and added small amounts of gaseous or dissolved ozone. Then they exposed the sample to light. Even light from a plain desk lamp would do, they reported.

Most sections of the doped nanotubes remain pristine and absorb infrared light normally, forming excitons, quasiparticles that tend to hop back and forth along the tube -- until they encounter oxygen.

"An exciton can explore tens of thousands of carbon atoms during its lifetime," Weisman said. "The idea is that it can hop around enough to find one of these doping sites, and when it does, it tends to stay there, because it's energetically stable. It becomes trapped and emits light at a longer (red-shifted) wavelength.

"Essentially, most of the nanotube is turning into an antenna that absorbs light energy and funnels it to the doping site. We can make nanotubes in which 80 to 90 percent of the emission comes from doped sites," he said.

Lab tests found the doped nanotubes' fluorescent properties to be stable for months.

Weisman said treated nanotubes could be detected without using visible light. "Why does that matter? In biological detection, any time you excite at visible wavelengths, there's a little bit of background emission from the cells and from the tissues. By exciting instead in the infrared, we get rid of that problem," he said.

The researchers tested their ability to view doped nanotubes in a biological environment by adding them to cultures of human uterine adenocarcinoma cells. Later, images of the cells excited in the near-infrared showed single nanotubes shining brightly, whereas the same sample excited with visible light displayed a background haze that made the tubes much more difficult to spot.

His lab is refining the process of doping nanotubes, and Weisman has no doubt about their research potential. "There are many interesting scientific avenues to pursue," he said. "And if you want to see a single tube inside a cell, this is the best way to do it. The doped tubes can also be used for biodistribution studies.

"The nice thing is, this isn't an expensive or elaborate process," Weisman said. "Some reactions require days of work in the lab and transform only a small fraction of your starting material. But with this process, you can convert an entire nanotube sample very quickly."