Articles from February 2012



Body heat to create power for your smartphone

Simply by touching a small piece of Power Felt – a promising new thermoelectric device developed by scientists, Corey Hewitt (Ph.D. graduate student)  has converted his body heat into an electrical current. Comprised of tiny carbon nanotubes locked up in flexible plastic fibers and made to feel like fabric, Power Felt uses temperature differences – room temperature versus body temperature, for instance – to create a charge. The research team  is  from Wake Forest University, North Carolina, , Center for Nanotechnology and Molecular Materials..

We waste a lot of energy in the form of heat. For example, recapturing a car’s energy waste could help improve fuel mileage and power the radio, air conditioning or navigation system,” Hewitt says. “Generally thermoelectrics are an underdeveloped technology for harvesting energy, yet there is so much opportunity.

Cost has prevented thermoelectrics from being used more widely in consumer products. Standard thermoelectric devices use a much more efficient compound called bismuth telluride to turn heat into power in products including mobile refrigerators and CPU coolers, but it can cost $1,000 per kilogram. Like silicon, researchers liken its affordability to demand in volume and think someday Power Felt would cost only $1 to add to a cell phone cover.

 

Source: http://news.wfu.edu/2012/02/22/power-felt-gives-a-charge/

12,000 nanotechnology experts in Iran

Dr. Saeed Sarkar from the Iran Nanotechnology Initiative Council announced that over 2,600 university lecturers have so far worked on nanotechnology in their articles and theses, and there are more than 12,000 nanotechnology experts at the MSc and PhD levels in Iran

Investigation by researchers with California University showed that Iran ranked 4th in a 2010 world’s ranking which indicates the portion of nanotech-related scientific articles (out of total scientific publications) published by the researchers of a country. The study also reported that about 12% of the international journal papers of Iranian researchers are connected to nanotechnology. On another investigation which assessed countries by the total number of nanotech scientific published articles, Iran managed to rank 14th.

A different concern: Western countries have to think that nanotechnology could be developed as well for war purposes. See the spybird drone developed by the US Defense agency DARPAhttp://www.nanocomputer.com/?p=242

 

:Source: http://en.nano.ir/index.php/news/show/2544

Single-Atom Transistor

Micro-engineering, physicists from the University of South Wales in Australia – UNSW – have created a working transistor consisting of a single atom placed precisely in a silicon crystal. The tiny electronic device, described today in a paper published in the journal Nature Nanotechnology, uses as its active component an individual phosphorus atom patterned between atomic-scale electrodes and electrostatic control gates. This unprecedented atomic accuracy may yield the elementary building block for a future quantum computer ( or nanocomputer) with unparalleled computational efficiencyUntil now, single-atom transistors have been realised only by chance, where researchers either have had to search through many devices or tune multi-atom devices to isolate one that works.

“But this device is perfect”, says Professor Michelle Simmons, group leader and director of the ARC Centre for Quantum Computation and Communication Technology at UNSW. “This is the first time anyone has shown control of a single atom in a substrate with this level of precise accuracy.” The microscopic device even has tiny visible markers etched onto its surface so researchers can connect metal contacts and apply a voltage, says research fellow and lead author Dr Martin Fuechsle from UNSW.

Our group has proved that it is really possible to position one phosphorus atom in a silicon environment – exactly as we need it – with near-atomic precision, and at the same time register gates,” he says. 

Source: http://newsroom.unsw.edu.au/news/science-technology/single-atom-transistor-%E2%80%9Cperfect%E2%80%9D

Chemist applies Google software to molecules

Aurora Clark, an associate professor of chemistry at Washington State University, has adapted Google’s PageRank software to create moleculaRnetworks, which scientists can use to determine molecular shapes and chemical reactions without the expense, logistics and occasional danger of lab experiments."What’s most cool about this work is we can take technology from a totally separate realm of science, computer science, and apply it to understanding our natural world,” says Clark. Google’s PageRank software, developed by its founders at Stanford University, uses an algorithm—a set of mathematical formulas—to measure and prioritize the relevance of various Web pages to a user’s search.

 Clark and her colleagues realized that the interactions between molecules are a lot like links between Web pages. Some links between some molecules will be stronger and more likely than others. "So the same algorithm that is used to understand how Web pages are connected can be used to understand how molecules interact,” says Clark.

Click on the picture of Aurora to get the video demonstration

Clark and colleagues from the University of Arizona discuss the software in a recent online article in The Journal of Computational Chemistry. Their work is funded by the U.S. Department of Energy’s Basic Energy Sciences program.

Source: http://news.wsu.edu/pages/publications.asp?Action=Detail&PublicationID=30228

‘Invisibility’ cloak could protect buildings from earthquakes

Dr William Parnell’s team from the  School of Mathematics at the University of Manchester, England, have been working on the theory of invisibility cloaks which, until recently, have been merely the subject of science fiction. In recent times, however, scientists have been getting close to achieving ‘cloaking’ in a variety of contexts. The work from the team at Manchester focuses on the theory of cloaking devices which could eventually help to protect buildings and structures from vibrations and natural disasters such as earthquakes.

According to the mathematician, “This research has shown that we really do have the potential to control the direction and speed of elastic waves. This is important because we want to guide such waves in many contexts, especially in nano-applications such as in electronics for example. 

If the theory can be scaled up to larger objects then it could be used to create cloaks to protect buildings and structures, or perhaps more realistically to protect very important specific parts of those structures.”, he added. This ‘invisibility’ could prove to be of great significance in safeguarding key structures such as nuclear power plants, electric pylons and government offices from destruction from natural or terrorist attacks.You can read old posts from nanocomputer.com, relating researches about 'invisble sounds' and objects.
http://www.nanocomputer.com/?p=1464
http://www.nanocomputer.com/?p=716
http://www.nanocomputer.com/?p=1168

Source: http://www.manchester.ac.uk/aboutus/news/display/?id=7968

Hamburger from stem cells

"The basic problem with current meat production is that it's inefficient". Instead of getting meat from animals raised in pastures, Professor Mark Post from Maastricht University in  Netherlands wants to grow steaks in lab conditions, directly from muscle stem cells. If successful, the technology will transform the way we produce food. "We want to turn meat production from a farming process to a factory process," he explained.

As head of the department of vascular physiology, he is in the vanguard of a new wave of research to create a way of producing meat that cuts out the need for animal husbandry altogether.

Source: http://www.maastrichtuniversity.nl/web/Main/Research.htm

 

Clck here to get a video interview about Mark Post researches

‘Smart’ microcapsules in a single step

A new, single-step of  fabricating microcapsules, which have potential commercial applications, in industries, including medicine, agriculture and diagnostics, have been developed by researchers at the University of Cambridge, England. The findings are published in the journal Science.
The ability to enclose materials in capsules between 10 and 100 micrometres in diameter, while accurately controlling both the capsule structure and the core contents, is a key concern in biology, chemistry, nanotechnology and materials science.

 

This method provides several advantages over current methods as all of the components for the microcapsules are added at once and assemble instantaneously at room temperature,” said lead author Jing Zhang, a PhD student in Professor Abell’s research group. “A variety of ‘cargos’ can be efficiently loaded simultaneously during the formation of the microcapsules. The dynamic supramolecular interactions allow control over the porosity of the capsules and the timed release of their contents using stimuli such as light, pH and temperature.”

Source: http://www.cam.ac.uk/research/news/smart-microcapsules-in-a-single-step/

Nanophotonic industry grows very fast

According to a new technical market research report,  the global market for nanophotonic devices was valued at nearly $2.5 billion in 2011 and is expected to increase to $10.9 billion in 2016, a five-year compound annual growth rate (CAGR) of 34.8%. The global market for nanophotonic devices can be separated into nine segments: nanophotonic diodes, near-field optics, solar cells, optical switches, nanophotonic ICs, holographic memory, nano-optical sensors, optical amplifiers, and add/drop filters. 

Nanophotonics involve the interaction of light with nanoscale structures and materials.  “Nanoscale” is defined as having at least one dimension measuring less than 100 nanometers, or billionths of a meter. At this scale, the properties that characterize larger systems do not necessarily apply – a fact that gives nanophotonics devices their unique properties.

 

Source: NANOTECHNOLOGY FOR PHOTONICS: GLOBAL MARKETS (NAN036B) from BCC Research  www.bccresearch.com.

Exploding Microcapsules to Kill Cancer Cells

How to kill cancer cells? To be effective, the drug carrier system needs to be able to identify and reach its target, and it needs to be able to release its payload at the target at the right time, or over a longer period of time.

Xian-Zheng Zhang, the Director of the Key Laboratory of Biomedical Polymers of Ministry of Education and a professor in the Department of Chemistry at Wuhan University in China, said, ."It is of great importance to design intelligent drug carriers that can specifically respond to physiopathological signals and allow explosive release of the loaded drugs while entrapping the drugs efficiently during the process of blood circulation,

" Zhang and his team have designed and fabricated a system that could effectively keep the drug entrapped in its carrier in the blood and normal tissues, but would allow explosive drug release under the right physiopathological stimuli – an acidic environment – once the drug carrier reaches the cancerous tissue.

Source: http://onlinelibrary.wiley.com/doi/10.1002/adfm.201102132/full.

Ferroelectric Switching in the Heart

Researchers at the University of Washington found that the wall of the aorta, the largest blood vessel carrying blood from the heart, exhibits ferroelectricity, a response to an electric field known to exist in inorganic and synthetic materials. "The result is exciting for scientific reasons,” said lead author Jiangyu Li, a UW associate professor of mechanical engineering. “But it could also have biomedical implications.”

A ferroelectric material is an electrically polar molecule with one side positively charged and the other negatively charged, whose polarity can be reversed by applying an electrical field. Ferroelectricity is common in synthetic materials and used for displays, memory storage, and sensors. (Related research by Li and colleagues seeks to exploit ferroelectric materials for tiny low-power, high-capacity computer memory chips.)

In the new study, Li collaborated with co-author Katherine Zhang at Boston University to explore the phenomenon in biological tissues. The only previous evidence of ferroelectricity in living tissue was reported last year in seashells. Others had looked in mammal tissue, mainly in bones, but found no signs of the property. The new study shows clear evidence of ferroelectricity in a sample of a pig aorta.  Researchers believe the findings would also apply to human tissue.

 

Source: http://www.washington.edu/news/articles/ferroelectric-switching-discovered-for-first-time-in-soft-biological-tissue

How to Weld Nanowires With Light

One area of intensive research at the nanoscale is the creation of electrically conductive meshes made of metal nanowires. Promising exceptional electrical throughput, low cost and easy processing, engineers foresee a day when such meshes are common in new generations of touch-screens, video displays, light-emitting diodes and thin-film solar cells.At the heart of the technique is the physics of plasmonics, the interaction of light and metal in which the light flows across the surface of the metal in waves, like water on the beach.

When two nanowires lie crisscrossed, we know that light will generate plasmon waves at the place where the two nanowires meet, creating a hot spot. The beauty is that the hot spots exist only when the nanowires touch, not after they have fused. The welding stops itself. It’s self-limiting,” explained Mark Brongersma, an associate professor of materials science engineering at Stanford and an expert in plasmonics. Brongersma is one of the study’s senior authors.
The rest of the wires and, just as importantly, the underlying material are unaffected,” noted Michael McGehee, a materials engineer and also senior author of the paper. “This ability to heat with precision greatly increases the control, speed and energy efficiency of nanoscale welding.”

Source: https://engineering.stanford.edu/news/stanford-engineers-weld-nanowires-light

Very Efficient Thin-Film Solar Cells

In a paper published in Nature Communications, a team of engineers at Stanford describes how it has created tiny hollow spheres of photovoltaic nanocrystalline-silicon and harnessed physics to do for light what circular rooms do for sound. The results, say the engineers, could dramatically reduce materials usage and processing cost.

 

“Nanocrystalline-silicon is a great photovoltaic material. It has a high electrical efficiency and is durable in the harsh sun,” said Shanhui Fan, a professor of electrical engineering at Stanford and co-author of the paper. “Both have been challenges for other types of thin solar films.” The downfall of nanocrystalline-silicon, however, has been its relative poor absorption of light, which requires thick layering that takes a long time to manufacture. By depositing two or even three layers of nanoshells atop one another, the team teased the absorption of light  higher still. With a three-layer structure, they were able to achieve total absorption of 75% of light in certain important ranges of the solar spectrum.

Sourcehttp://engineering.stanford.edu/news/nanoshell-whispering-galleries-improve-thin-solar-panels