Computers are getting smaller and smaller. And as hand-held devices, from mobile phones and cameras to music players and laptops, get more powerful, the race is on to develop memory formats that can satisfy the ever-growing demand for information storage on tiny formats.

Researchers at The University of Nottingham are now exploring ways of exploiting the unique properties of carbon nanotubes to create a cheap and compact memory cell that uses little power and writes information at high speeds.

Continue reading…

Buckypaper from frit compression of multi-walled carbon nanotubes

Ten times lighter, but potentially 500 times stronger than steel when sheets of it are stacked and pressed together to form a composite, Buckypaper could revolutionise the way everything from airplanes to TVs are made.

Buckypaper is made from carbon nanotubes 50,000 times thinner than a human hair. Buckypaper is named after Buckminsterfullerene, or Carbon 60 – a type of carbon molecule whose powerful atomic bonds make it twice as hard as a diamond.

Buckypaper owes its strength to the huge surface area of each of the nanotubes it comprises.

Continue reading…

A team of researchers have developed an improved carbon nanotube-based material that mimics the ability of gecko feet to grip surfaces.

The gecko has microscopic branched elastic hairs in their toes that take advantage of atomic-scale attractive forces to grip surfaces and support surprisingly heavy loads. The carbon-nanotube-based material, described by the research team creates a directionally varied (anisotropic) adhesive force. With a gripping ability nearly three-times the previous record, and ten times better than a real gecko at resisting perpendicular shear forces, the new carbon nanotube array could give artificial gecko feet the ability to tightly grip vertical surfaces while being easily lifted off when desired.

Continue reading…

A fresh discovery about the way water behaves inside carbon nanotubes could have implications in fields ranging from the function of ultra-tiny high-tech devices to scientists’ understanding of biological processes, according to researchers from the University of North Carolina at Chapel Hill.

The findings, published in the Oct. 3, 2008, issue of the journal, relate to a property of so-called “nano-confined” water – specifically, whether hollow carbon nanotubes take in the liquid easily or reluctantly, depending on their temperature.

As well as shedding light on the characteristics of human-made nanomaterials, researchers note that such properties are relevant to the workings of biological structures and phenomena which also function at nano-scales.

The team of scientists, led by Yue Wu, Ph.D., professor of physics in the UNC College of Arts and Sciences, examined carbon nanotubes measuring just 1.4 nanometers in diameter (one nanometer is a billionth of a meter). The seamless cylinders were made from rolled up graphene sheets, the exfoliated layer of graphite.

“Normally, graphene is hydrophobic, or ‘water hating’ – it repels water in the same way that drops of dew will roll off a lotus leaf,” said Wu. “But we found that in the extremely limited space inside these tubes, the structure of water changes, and that it’s possible to change the relationship between the graphene and the liquid to hydrophilic or ‘water-liking’.”

The UNC team did this by making the tubes colder. Using nuclear magnetic resonance – similar to the technology used in advanced medical MRI scanners – they found that at about room temperature (22 degrees centigrade), the interiors of carbon nanotubes take in water only reluctantly.

However, when the tubes were cooled to 8 degrees, water easily went inside. Wu said this shows that it is possible for water in nano-confined regions – either human-made or natural – to take on different structures and properties depending on the size of the confined region and the temperature.

Nanotechnology seems to be invading all facets of modern life. Pretty soon, carbon nanotubes may even filter your water.

Researchers at the Bhabha Atomic Research Center in India are investigating the hollow carbon fibers as a potential water filter. They believe the unique chemical properties of nanotubes mean that only water molecules can pass through their interiors, while toxic metal ions, viruses, and bacteria cannot.

Additionally, the smooth, water-repellent interior of the nanotubes means that a filter made from the technology would have a high flow rate of water without fouling—so it would be very efficient.

Read more at Cleantechnica

Scientists from the University of Tokyo have developed a stretchy, rubbery material which is able to conduct electricity.

When the material, which comprises single wall carbon nanotubes, elastic resin and an ionic liquid, is attached to a grid of tiny transistors, it cab be stretched up to 2.34 times its original size, without adverse effects to the conductivity. Later it reverts to its original form.

A similar material was developed in 2005, but was only able to stretch 1.25 longer than its original size, and its conductivity limited to 10S/cm. The newly developed material has a conductivity of 57S/cm.

According to a paper published by the scientists working on the project, the material could be used to create flexible electronics, and there have been suggestions it could be used on the joints of a robot’s arm.

Researchers from Perdue University and the University of Illinois at Urbana-Champaign, have overcome a major obstacle in producing transistors from networks of carbon nanotubes.

‘Nanonets’ are made of tiny semiconducting cylinders called single walled carbon nanotubes. These metal tubes then link together in meandering threads that eventually stretch across the width of the transistor causing a short circuit.

Researcher John Rogers, explained: “Other researchers have proposed eliminating the metallic nanotubes. Instead we have found a very nice way of essentially removing the effect of these metallic nanotubes without actually eliminating them.”

Continue reading…

A new method of sorting single-walled carbon nanotubes (SWNTs) according to their chirality, could help solve a long standing problem in the fabrication of nanotube-based electronics.

A SWNT can behave as either a metal or a semiconductor, depending on the spatial arrangement of its carbon atoms, or chirality. SWNTs are produced as a mixture of both types, however, these do not work well together and need to be separated before use.

While number of methods have been devised to separate the two types of SWNTs, none have proven practical for large scale applications.

Continue reading…

The Chair of Display Technology at Universitaet Stuttgart has worked in collaboration with Nano Proprietary’s subsidiary, applied Nanotech Inc (ANI), to increase the fabrication yield of carbon nanotube (CNT) thin film transistors (TFTs) for use in displays, electronic circuits, sensors, memory chips and other applications that are transitioning from rigid substrates, such as silicon and glass, to flexible substrates.

ANI and the Universitaet Stuttgart have worked together to increase the fabrication yield of carbon nanotube TFTs using ANI’s proprietary printing-like method of carbon nanotube deposition. The TFTs exceed an on/off ratio of five orders of magnitude and achieve the electron mobility necessary for thei utilisation for low temperature plastic-based substrates.

Continue reading…

A nanotechnology-based biosensor that can be used to detect trace amounts of specific bacteria, viruses and parasites has been developed by NASA’s Ames Research Center.

Commenting on the new development, Meyya Meyyappan, chief scientist for exploration technology and former director of the center for Nanotechnology at Ames, explained: “The biosensor makes use of ultra-sensitive carbon nanotubes which can detect biohazards at very low levels.

“When biohazards are present, the biosensor generates an electrical signal, which is used to determine the presence and concentration levels of specific micro-organisms in the sample. Because of their tiny size, millions of nanotubes can fit on a single biosensor chip.”

Continue reading…

Some forms of carbon nanotubes could be as harmful as asbestos if inhaled in sufficient quantities, according to a new study.

The study, published in Nature Nanotechnology, used established methods to see if specific types of nanotubes have the potential to cause mesothelioma — a cancer of the lung lining that can take 30-40 years to appear following exposure. The results show that long, thin multi-walled carbon nanotubes that look like asbestos fibres, behave like asbestos fibres.

Continue reading…