February 10, 2011 — Research teams for Professor Yutaka Ohno Nagoya University (Japan) and Prof. Esko I. Kauppinen, Aalto University (Finland), have developed a simple and rapid technique to fab carbon nanotube (CNT) thin film transistors on plastic film.

The researchers believe they have produced the world’s first carbon nanotubes based on sequential logic integrated circuits (ICs). In the recently developed method, nanotubes are grown using gas phase filtration and thin film transfer to the crucible of plastic on top. This creates a clean and uniform film in a few seconds, researchers report. This method could further be developed into a high-speed roll-to-roll (R2R) manufacturing process.

The inventors believe that the developed carbon nanotube manufacturing process will allow for flexible electronics, such as electronic paper, made at competitive production rates. 

Interest in lightweight and flexible devices, such as a flexible mobile phone and electronic paper, has increased recently. These devices require flexible electronics components, produced cheaply and quickly directly onto plastic substrates.

Carbon nanotubes offer good conductivity and chemical stability, but current CNT manufacturing does not result in CNT transistors with the properties expected. Nanotubes manufactured in the current synthesis process are partially destroyed, whereas the gas phase filtration process leaves them whole, say researchers.

Research results were published in the February 6, 2011 issue of Nature Nanotechnology: http://www.nature.com/nnano/index.html

The study was funded by the New Energy and Industrial Technology Development Organization (Nedo), Japan and the Aalto University Multidisciplinary Institute of Digitalization and Energy Research (MIDE).

For more information, visit http://electronics.tkk.fi/fi/ajankohtaista/uutiset/view/hiilen_nanoputket_valmistettu_muovikalvolle/

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February 9, 2011 — Nanocarbon products include single-walled carbon nanotubes (SWCNT or MWNT) and multi-walled carbon nanotubes (MWCNT or MWNT), fullerenes, graphene, carbon nanofiber and nanodiamonds. Carbon nanotubes are microscopic, tube-shaped structures, which essentially have a composition of a graphite sheet rolled into a tube.

Carbon nanotubes have unique, interesting and potentially useful electrical and mechanical properties, and offer potential for various uses in electronic devices. Carbon nanotubes also feature extremely high electrical conductivity, very small diameters (much less than 100nm), large aspect ratios (i.e. length/diameter ratios greater than 1000), and a tip-surface area near the theoretical limit (the smaller the tip-surface area, the more concentrated the electric field, and the greater the field enhancement factor). These features make carbon nanotubes ideal for electron field emitters, white light sources, lithium secondary batteries, hydrogen storage cells, transistors, and cathode ray tubes (CRTs).

According to a recently published report from iRAP, Inc., ET-113: Production and Application of Carbon Nanotubes, Carbon Nanofibers, Fullerenes, Graphene and Nanodiamonds: A Global Technology Survey and Market Analysis, the production capacity for all products was 4,065 tons in 2010, and is expected to exceed 12,300 tons in 2015. The actual production was less than 25% of the capacity in 2010 and about 50% of the capacity in 2015. Total production value is estimated at about $435 million in 2010 and is expected reach a value of $1.3 billion in 2015.

Share of nanocarbon production value according to types, 2010 and 2015 ($ Millions) Source: iRAP, Inc.

Production capacity far exceeds actual production. Only about 340 tons of carbon nano products were produced in 2008, about 500 tons in 2009 and about 710 tons are expected to have been produced in 2010, which represents about 17% of capacity. However, actual production is expected to reach more than 9300 tons in 2015, representing a growth rate of 67.3% annually and about 80% of production capacity.

Prices for all products are expected to fall by an average of about 12% a year for the next five years. Growth is chiefly driven by multi-walled carbon nanotubes. World production capacity for multi-wall carbon nanotubes exceeded 390 tons in 2008, reached 1,500 tons in 2009, and is estimated to exceed 3,400 tons per year (tpy) by the end of 2010. Production capacity for MWNT is projected to reach 9,400 tons by 2015. 

SWCNTs are the most expensive nano carbon product. They are much more difficult to produce than MWCNTs and are best suited for electronic applications. In 10 to 15 years, SWCNT are expected to replace silicon as the key material in computer chips. 

Despite the quickly growing capacity for CNTs, demand has not yet caught up with capacity.  However, manufacturers have been increasing capacity to be ready to capitalize on that future demand, which is expected to grow rapidly over the next five to ten years. 

For both SWCNTs and MWCNTs, Asia’s production capacity is two to three times higher than that estimated for North America and Europe combined; Japan is the prominent leader in the production of MWCNTs, but China and Korea are rapidly catching up.  Use of CNTs in lithium-ion battery electrodes is the current driving force of ton-scale MWCNT production in Japan.

More details of the report are available from Innovative Research and Products (iRAP), Inc., P.O. Box 16760, Stamford, CT 06905, USA, (203) 569-7909, [email protected] or at http://www.innoresearch.net/reportlist.aspx?cid=7

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February 8, 2011 — Carbon nanotubes (CNTs) have many attractive properties, and their structure and areas of application can be compared with those of graphene. To exploit these properties, however, it is necessary to have full control of the manufacturing process. Scientists at the University of Gothenburg successfully defended a thesis on this subject, "In Silco Studies of Carbon Nanotubes and Metal Clusters."

"Our results show that the metal particles that form the basis of the manufacture of carbon nanotubes must have a certain minimum size, in order for growth to start and to continue. It is also probable that the particles are in liquid form at a manufacturing temperature of around 800°C, even though the metals used may have much higher melting points," says Anders Börjesson from the Department of Physics at the University of Gothenburg.

The scientists used various computer models to study in detail properties that are difficult or impossible to examine in experimental conditions. While the diameter of the nanotubes is of the order of one billionth of a metre, and they can be as thin as a single carbon layer, the length of the tubes can extend from the nanometer scale up to several decimeters. Carbon nanotubes can be regarded as thin threads of pure carbon, whose length can be a billion times greater than their thickness.

The thesis In Silco Studies of Carbon Nanotubes and Metal Clusters has been successfully defended. Supervisor: Professor Kim Bolton. The research has been a collaboration between the University of Gothenburg and the University of Borås. Link to the thesis: http://bada.hb.se/handle/2320/6908

For more information on this research, contact Anders Börjesson, Department of Physics, University of Gothenburg, at +46(0)31 786 9143, +46(0)70 240 1145, [email protected]

Courtesy of Anita Fors

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February 8, 2011 — The Global School for Advanced Studies (GSAS) invites post-doctorate fellows and other senior student researchers from around the world to apply for the June 20-26 session on "Graphene Fundamentals and Applications" in Grenoble, France.

Selected students, who will receive full travel and lodging support, will compete for fellowships to implement graphene-related research at CEA in Grenoble beginning in January 2012.

Hosted by the GIANT Innovation Campus in Grenoble, this program will create several research teams and challenge them to design a project based on graphene that will leverage their complementary strengths. Each team will have members from around the world and a balance of capabilities, including materials synthesis, characterization, device design and fabrication, theory and measurement.

Teams participating in the Graphene Fundamentals and Applications Session will receive project mentoring from leading global experts. These include Harry Kroto, a Nobel Prize winning professor in the Department of Chemistry and Biochemistry at Florida State University; Sumio Iijima, research fellow at NEC and a professor of materials science at Meijo University in Nagoya who is credited with discovering carbon nanotubes; and Daniel Neumaier, of AMO Research Foundry, and coordinator of the EU’s Graphene-based Nanoelectronic Devices (GRAND), 7th Framework Programme.

Founded in 2006, GSAS is designed to foster innovation in critical global challenge areas such as energy, environment, and health, while training the next generation of young researchers with global leadership capabilities.

The program, which rotates its sessions among campuses and facilities in different countries, groups selected students into interdisciplinary teams that attend lectures, receive expert mentoring and are challenged to develop detailed collaborative research plans in one of the challenge areas. The team whose research plan is chosen receives research fellowships to carry out its projects at GSAS member institutions.

The Graphene Fundamentals and Applications Session is organized by the National Science Fundation (NSF), Northwestern University and CEA-Grenoble (in the frame of GIANT).

Senior graduate students and postdocs from all related disciplines are invited to apply. Visit www.gsasprogram.org for more information.

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