Nanotechnology - Technology for every facet of life
Thursday, September 25, 2014
Future flexible electronics based on carbon nanotubes
Rsearchers from the University of Texas at Austin and Northwestern University have demonstrated a new method to improve the reliability and performance of transistors and circuits based on carbon nanotubes (CNT), a semiconductor material that has long been considered by scientists as one of the most promising successors to silicon for smaller, faster and cheaper electronic devices. The result appears in a new paper published in the journal Applied Physics Letters, from AIP Publishing.
In the paper, researchers examined the effect of a fluoropolymer coating called PVDF-TrFE on single-walled carbon nanotube (SWCNT) transistors and ring oscillator circuits, and demonstrated that these coatings can substantially improve the performance of single-walled carbon nanotube devices. PVDF-TrFE is also known by its long chemical name polyvinyledenedifluoride-tetrafluoroethylene.
"We attribute the improvements to the polar nature of PVDF-TrFE that mitigates the negative effect of impurities and defects on the performance of semiconductor single-walled carbon nanotubes," said Ananth Dodabalapur, a professor in the Cockrell School of Engineering at UT Austin who led the research. "The use of [PVDF-TrFE] capping layers will be greatly beneficial to the adoption of single-walled carbon nanotube circuits in printed electronics and flexible display applications."
The work was done in collaboration between Dodabalapur's group at UT Austin and Mark Hersam's group at Northwestern University as part of a Multi-University Research Initiative (MURI) supported by the Office of Naval Research.
A potential successor to silicon chips
Single-walled carbon nanotubes (SWCNT) are just about the thinnest tubes that can be wrought from nature. They are cylinders formed by rolling up a material known as graphene, which is a flat, single-atom-thick layer of carbon graphite. Most single-walled carbon nanotubes typically have a diameter close to 1 nanometer and can be twisted, flattened and bent into small circles or around sharp bends without breaking. These ultra-thin carbon filaments have high mobility, high transparency and electric conductivity, making them ideal for performing electronic tasks and making flexible electronic devices like thin film transistors, the on-off switches at the heart of digital electronic systems.
"Single-walled carbon nanotube field-effect transistors (FETs) have characteristics similar to polycrystalline silicon FETs, a thin film silicon transistor currently used to drive the pixels in organic light-emitting (OLED) displays," said Mark Hersam, Dodabalapur's coworker and a professor in the McCormick School of Engineering and Applied Science at Northwestern University. "But single-walled carbon nanotubes are more advantageous than polycrystalline silicon in that they are solution-processable or printable, which potentially could lower manufacturing costs."
Tuesday, September 16, 2014
Nano engineering advances bone-forming material
The advancement means the successful use of synthetic materials in bone grafts for human patients is a step closer. The material could also have potential future applications in fracture repair and reconstructive surgery.
Currently the patient's own bone, donated bone or artificial materials are used for bone grafts but limitations with all these options have prompted researchers to investigate how synthetic materials can be enhanced.
Dr Eddy Poinern and his team from the Murdoch Applied Nanotechnology Research Group worked with powdered forms of the bio ceramic hydroxyapatite (HAP) to form pellets with a sponge-like structure which were then successfully implanted behind the shoulders of four sheep by collaborators from the School of Veterinary and Life Sciences at Murdoch University.
HAP is already being used in a number of biomedical applications such as bone augmentation in dentistry because of its similarity to the inorganic mineral component of human bone. But treatments of HAP so that it can be successfully used in a bone graft have yet to be developed because of the complexities involved with compatibility and HAP's load bearing limitations.
FDA Advisory Committee Votes 14-1 in Favor of Saxenda (liraglutide) for Obesity
In continuation of my update on Lirglutide
Novo Nordisk today announced that the Endocrinologic and Metabolic Drugs Advisory Committee (EMDAC) of the Food and Drug Administration (FDA) has completed its meeting regarding the New Drug Application (NDA) for Saxenda, the intended brand name for liraglutide 3 mg, a once-daily human GLP-1 analogue for the treatment of obesity.
Monday, September 15, 2014
More efficient fuel cells for vehicles: Angling chromium to let oxygen through -- ScienceDaily
Rsearchers have been trying to increase the efficiency of solid oxide fuel cells by lowering the temperatures at which they run. More efficient fuel cells might gain wider use in vehicles or as quiet, pollution-free, neighborhood electricity generating stations. A serendipitous finding has resulted in a semiconducting material that could enable fuel cells to operate at temperatures two-thirds lower than current technology, scientists reported August 18 in Nature Communications.
Friday, September 12, 2014
Graphene paints a corrosion-free future: Keep food fresh longer? -- ScienceDaily
A thin layer of graphene paint can make impermeable and chemically resistant coatings which could be used for packaging to keep food fresh for longer and protect metal structures against corrosion, new findings from The University of Manchester show.
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