Friday, March 26, 2010

This week in nanotechnology - March 26

Nanotechnology makes portable seawater desalination device possible. Researchers have now demonstrated a new, efficient and fouling-free desalination process based on the ion concentration polarization (ICP) phenomenon - a fundamental electrochemical transport phenomenon that occurs when an ion current is passed through ion-selective membranes - for direct desalination of sea water.

A team has used atomic layer deposition to incorporate biological functionality into complex nanomaterials, which could lead to a new generation of medical and environmental health applications. For example, the researchers show how the technology can be used to develop effective, low-cost water purification devices that could be used in developing countries.

Nanotechnology-based retinal implant technology could lead to bionic eye. Yael Hanein of Tel Aviv University's School of Electrical Engineering has foundational research that may give sight to blind eyes, merging retinal nerves with electrodes to stimulate cell growth. Successful so far in animal models, this research may one day lay the groundwork for retinal implants in people.

These are two rat neuronal cells bound to a rough carbon nanotube mat.

These are two rat neuronal cells bound to a rough carbon nanotube mat.

Researchers in London have found that nanometer size diamonds can be attached to a wide range of substrates and that they can promote the growth of neurons without the need for the complex layers of proteins normally required

Three new complementary research projects will turn carbon from a pollutant into useful products that could help both industry and the environment. Nanotechnology solutions will be used to: 1) convert carbon dioxide (CO2) into chemicals that could be used in fuel cells for laptops and mobile phones. 2) produce vehicle fuels from CO2 using an 'artificial leaf' concept. 3) remove CO2 from the atmosphere and lock it into useful products such as polymers, carbohydrates or fuels.

Saturday, March 20, 2010

This week in nanotechnology - March 19, 2010

In findings that took the experimenters three years to believe, engineers have demonstrated that light itself can twist ribbons of nanoparticles. Matter readily bends and twists light. That's the mechanism behind optical lenses and polarizing 3-D movie glasses. But the opposite interaction has rarely been observed. While light has been known to affect matter on the molecular scale - bending or twisting molecules a few nanometers in size - it has not been observed causing such drastic mechanical twisting to larger particles.

A new high-performance anode structure based on silicon-carbon nanocomposite materials could significantly improve the performance of lithium-ion batteries used in a wide range of applications from hybrid vehicles to portable electronics. Produced with a "bottom-up" self-assembly technique, the new structure takes advantage of nanotechnology to fine-tune its materials properties, addressing the shortcomings of earlier silicon-based battery anodes. The simple, low-cost fabrication technique was designed to be easily scaled up and compatible with existing battery manufacturing.

For two decades, scientists have been pursuing a potential new way to treat bacterial infections, using naturally occurring proteins known as antimicrobial peptides (AMPs). Now, MIT scientists have recorded the first microscopic images showing the deadly effects of AMPs, most of which kill by poking holes in bacterial cell membranes.

This image, taken with atomic force microscopy, shows E. coli bacteria after they have been exposed to the antimicrobial peptide CM15. The peptides have begun destroying the bacteria’s cell walls

This image, taken with atomic force microscopy, shows E. coli bacteria after they have been exposed to the antimicrobial peptide CM15. The peptides have begun destroying the bacteria’s cell walls.

Here's an exaple of apractical application of nanotechnology: Cassava is a tropical root vegetable and staple crop for millions of people in sub-Saharan Africa. However, it's tricky to handle: Once the root is removed from the ground, it spoils within one to three days, so farmers must get it to processing centers as soon as possible after harvesting it. If they don’t, the crop goes to waste. A simple way to prolong cassava's shelf life could help farmers avoid that waste and sell their crop beyond their local region. Paula Hammond, MIT professor of chemical engineering, and other scientists are now working on an innovative way to help them do that, using nanotechnology. Their idea is to design a plastic storage bag lined with nanoparticles that would react with oxygen, preventing the roots’ oxygen-induced rotting.

Scientists have devised a molecular 'LEGO toolkit' which can be used to assemble a vast number of new and functional chemical compounds. Using molecules as building blocks they have been able to construct a molecular scaffold based on tiny (nano-scale) storage cubes. This new ‘designer route’ opens the door to many new compounds that, potentially, are able to act as the ion sensors, storage devices, and catalysts of the future.

Artificial photosynthesis can offer a clean and portable source of energy supply as durable as the sunlight. Using sunlight to split water molecules and form hydrogen fuel is one of the most promising tactics for kicking our carbon habit. Of the possible methods, nature provides the blueprint for converting solar energy in the form of chemical fuels. A natural leaf is a synergy of the elaborated structures and functional components to produce a highly complex machinery for photosynthesis in which light harvesting, photoinduced charge separation, and catalysis modules combined to capture solar energy and split water into oxygen and hydrogen efficiently. Chinese researchers have now demonstrated the design of an efficient, cost-effective artificial system to mimic photosynthesis by copying the elaborate architectures of green leaves, replacing the natural photosynthetic pigments with man-made catalysts and thereby realizing water splitting- a major advance in energy conversion.

Friday, March 12, 2010

This week in nanotechnology - March 12, 2010

A team of scientists at MIT have discovered a previously unknown phenomenon that can cause powerful waves of energy to shoot through minuscule wires known as carbon nanotubes. The discovery could lead to a new way of producing electricity, the researchers say.

Another weapon in the arsenal against cancer: Nanoparticles that identify, target and kill specific cancer cells while leaving healthy cells alone. Researchers synthesized nanoparticles made of gold sandwiched between two pieces of iron oxide. They then attached antibodies, which target a molecule found only in colorectal cancer cells, to the particles. Once bound, the nanoparticles are engulfed by the cancer cells. To kill the cells, the researchers use a near-infrared laser, which is a wavelength that doesn't harm normal tissue at the levels used, but the radiation is absorbed by the gold in the nanoparticles. This causes the cancer cells to heat up and die.

Researchers at Stanford University have successfully developed brand new concept of organic lighting-emitting diodes (OLEDs) with a few nanometer of graphene as transparent conductor. This paved the way for inexpensive mass production of OLEDs on large-area low-cost flexible plastic substrate, which could be rolled up like wallpaper and virtually applied to anywhere you want.

Organic lighting-emitting diodes (OLEDs) with a few nanometer of graphene as transparent conductor

Organic lighting-emitting diodes (OLEDs) with a few nanometer of graphene as transparent conductor.

Researchers have successfully demonstrated a futuristic semiconductor technology that will pave the way for the next generation of electrical and information technology systems: Magnetic quantum dot technology is expected to underpin future communications and resolve power consumption and variability issues in today's microelectronics industry by providing computers and other devices with extraordinary electrical and magnetic properties.

Consider this T-shirt: It can monitor your heart rate and breathing, analyze your sweat and even cool you off on a hot summer’s day. What about a pillow that monitors your brain waves, or a solar-powered dress that can charge your phone or MP3 player? This is not science fiction – this is cotton in 2010. Researchers have developed cotton threads that can conduct electric current like metal wire, yet remain light and comfortable enough to give a whole new meaning to multi-functional garments.

Friday, March 5, 2010

This week in nanotechnology - March 5, 2010

A new study reveals that thermocells based on carbon nanotube electrodes might eventually be used for generating electrical energy from heat discarded by chemical plants, automobiles and solar cell farms. Efficiently harvesting the thermal energy currently wasted in industrial plants or along pipelines could create local sources of clean energy that in turn could be used to lower costs and shrink an organization’s energy footprint.

Another decisive step forward in the development of quantum computers has been successful. For the first time ever, researchers have accomplished to place two nitrogen atoms in a distance of only few nanometers, so that laser excitation will be capable of creating a quantum mechanical coupling. The key to the solution: it works with high precision, reliably, and even at room-temperature only in a diamond.

Researchers made a significant step towards replacing electrical signals that communicate via copper wires between computer chips with tiny silicon circuits that communicate using pulses of light. The device, called a nanophotonic avalanche photodetector, is the fastest of its kind and could enable breakthroughs in energy-efficient computing that can have significant implications for the future of electronics.

The work by a team of geomicrobiologists paves the way for nanometer-size magnets – used in mobile phones and recording devices – to be made without the usual nasty chemicals and energy intensive methods. They studied iron-reducing bacteria that occur naturally in soils and sediments and found they can be used to create iron oxide nanoparticles with magnetic properties similar to those created through complex chemical processes.

Surface energy is ubiquitous in nature and it plays an important role in many scientific areas such as for instance surface physics, biophysics, surface chemistry, or catalysis. So far it has been impractical to consider utilizing surface energy as an energy source because there are few molecules or atoms involved in the surface interaction and the density of surface energy is low. However, due to the lower power consumption requirements of nanotechnology devices and the higher specific surface area for nanomaterials it appears attractive to use surface energy at the nanoscale.