Archive for the ‘nanotubes’ tag
Simulations help explain fast water transport in nanotubes
By discovering the physical mechanism behind the rapid transport of water in carbon nanotubes, scientists at the University of Illinois have moved a step closer to ultra-efficient, next-generation nanofluidic devices for drug delivery, water purification and nano-manufacturing.
“Extraordinarily fast transport of water in carbon nanotubes has generally been attributed to the smoothness of the nanotube walls and their hydrophobic, or water-hating surfaces,” said Narayana R. Aluru, a Willett Faculty Scholar and a professor of mechanical science and engineering at the U. of I.
Read more on: Electronics, nanotubesTE material turns waste heat into electricity
Researchers at Ohio State University have invented a new material designed to make cars more efficient by converting heat wasted through engine exhausts into electricity.
Scientists rate the efficiency of thermoelectric (TE) materials based on how much heat they can convert into electricity at a given temperature. To maximise the amount of electricity produced by a TE material, engineers would normally try to limit the amount of heat that can pass through it without being captures and converted to electricity. So the typical strategy for making a good TE material is to lower its thermal conductivity.
Project leader, Joesph Heremans took a different approach, focussing on how to convert the maximum amount of heat that was naturally trapped in the TE material. To do this he took embraced some new ideas in quantum mechanics.
Read more on: Automotive, electricity, material, nanotubes, TE, thermoelectricSilicon coating sorts nanotube groups
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.
Read more on: carbon nanotubes, chirality, Electronics, nanotubes, Silicon, SWNTs, transistorsNanotube device set to rival transistor-switched silicon-based memory
Researchers have produced a novel memory device set to rival transistor-switched silicon-based memory.
Conventional memory chips in electronic devices are made up of transistors, resistors and capacitors built in layers on a silicon wafer through a photolithographic process, during which precise patterns are etched on the silicon to form the chip. Today’s technology allows several million transistors to be built on a piece of silicon the size of a pinhead, but many researchers believe this form of memory has been pushed to its limits.
Researchers have been trying to create electromechanically driven switches small enough to rival transistor-switched silicon-based memory. Unlike transistors, electromechanically driven switches contain moving parts. Not only do electromechanical devices have excellent ON-OFF rations and fast switching characteristics, but the physical separation between the switch and capacitor in such devices means the data leakage problem is significantly reduced. However, until now, the technology has not been a viable alternative to silicon-based arrangements because it involved larger cells and more complex fabrication processes.
Professor Gehan Amaratunga and a team of international researchers have remedied these drawbacks by creating a novel nanoelectromechanical (NEM) switched capacitor based in vertically aligned multi-walled carbon nanotubes (CNTs).
Read more on: capacitor, electromechanically, Electronics, memory, nanotubes, NEM, Silicon, switch, transistorAsbestos warning on carbon nanotubes
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.
Read more on: carbon nanotubes, Electronics, nanotechnology, nanotubesChemists measure chilli sauce hotness with nanotubes
Oxford chemists have found a way of using carbon nanotubes to judge the heat of chilli sauces.
The technology might soon be available commercially as a cheap, disposable sensor for use in the food industry. Professor Richard Compton and his team at Oxford University have developed a sensitive technique to measure the levels of capsaicinoids, the substances that make chillies hot, in samples of chilli sauce.
Read more on: Electronics, nanotubes