Monday, May 18, 2009

A team of Australian and Korean researchers led by Geoffrey M. Spinks and Seon Jeong Kim has now developed a novel, highly porous, sponge-like material whose mechanical properties closely resemble those of biological soft tissues. It consists of a robust network of DNA strands and carbon nanotubes.

Soft tissues, such as tendons, muscles, arteries, and skin or other organs, obtain their mechanical support from the extracellular matrix, a network of protein-based nanofibers. Different protein morphologies in the extracellular matrix produce tissue with a wide range of stiffness. Implants and scaffolding for tissue growth require porous, soft materials -- which are usually very fragile. Because many biological tissues are regularly subjected to intense mechanical loads, it is also important that the implant material have comparable elasticity in order to avoid inflammation. At the same time, the material must be very strong and resilient, or it may give out.

The new concept uses DNA strands as a matrix; the strands completely “wrap” the scaffold-forming carbon nanotubes in the presence of an ionic liquid, networking them to form a gel. This gel can be spun: just as silk and synthetic fibers can be wet-spun for textiles, the gel can be made into very fine threads when injected into a special bath. The dried fibers have a porous, sponge-like structure and consist of a network of intertwined 50 nm-wide nanofibers. Soaking in a calcium chloride solution further cross-links the DNA, causing the fibers to become denser and more strongly connected.

These spongy fibers resemble the collagen fiber networks of the biological extracellular matrix. They can also be knotted, braided, or woven into textile-like structures. This results in materials that are as elastic as the softest natural tissues while simultaneously deriving great strength from the robust DNA links.

An additional advantage is the electrical conductivity of the new material, which can thus also be used in electrodes for mechanical actuators, energy storage, and sensors. For example, the researchers were able to produce a hydrogen peroxide sensor. The carbon nanotubes catalyze the oxidation of hydrogen peroxide, which results in a measurable current. Hydrogen peroxide plays a role in normal heart function and certain heart diseases. A robust sensor with elasticity similar to the heart muscle would be of great help in researching these relationships

Wednesday, May 6, 2009

production of alternating current by nanotechnology

Researchers have developed a new type of small-scale electric power generator able to produce alternating current through the cyclical stretching and releasing of zinc oxide wires encapsulated in a flexible plastic substrate with two ends bonded.
Flexible charge pump: New small-scale generator produces alternating current by stretching zinc oxide wires of the pump.

gold nanostar shape of future

Rods, cones, cubes and spheres move aside. Tiny gold stars, smaller than a billionth of a meter, may hold the promise for new approaches to medical diagnoses or testing for environmental contaminants.

new generation of paper thin loudspeakers through nanotechnology






In research that may redefine ear buds, earphones, stereo loudspeakers, and other devices for producing sound, researchers in China are reporting development of flexible loudspeakers thinner than paper that might be inserted into the ears with an index finger or attached to clothing, walls, or windows. Their report on what may be the world's thinnest loudspeakers, made from transparent carbon nanotube films, is scheduled for the December 10 issue of ACS' Nano Letters

detection of lung cancer by nanotech tubes



Using an array of nanotube devices, each coated with a different organic material, researchers at the Israel Institute of Technology have developed diagnostic system that may be able to diagnose lung cancer simply by sampling a patient%u2019s breath. The results of this study, which was led by Hossam Haick, Ph.D., appear in the journal Nano Letters.


Scientists at the University of Liverpool have developed a new technology which can dramatically improve the effectiveness of antibacterial treatments. which have capacity to drugs by improving their anti bacterial action against the harmful disease causing bacteria.

lower cost solar cells through nanotechnology



We never knew where basic research may lead. For decades materials scientists have been experimenting with a corkscrew-like polymer structure called a gyroid. Now an international team of researchers has shown that the gyroid structure can be used to "self-assemble" a low-cost photovoltaic cell.

this is a low cost solar cell which needs the knowledge of nanotechnology and uses the solar power of the sunlight.

core concepts of molecular nanotechnology






Manufactured products are made from atoms. properties of those products depend on the arrangements of the atoms in the manufactured product. for example:If we rearrange the atoms in coal we can make diamond. If we rearrange the atoms in sand (and add a few other trace elements) we can make computer chips. If we rearrange the atoms in dirt, water and air we can make potatoes.


Todays manufacturing methods are very crude at the molecular level. Casting, grinding, milling and even lithography move atoms in great thundering statistical herds. It's like trying to make things out of LEGO blocks with boxing gloves on your hands. In the future, nanotechnology will let us take off the boxing gloves.


We'll be able to snap together the fundamental building blocks of nature easily, inexpensively and in most of the ways permitted by the laws of physics. This will be essential if we are to continue the revolution in computer hardware beyond about the next decade, and will also let us fabricate an entire new generation of products that are cleaner, stronger, lighter, and more precise.


the word "nanotechnology" has become very popular and is used to describe many types of research where the characteristic dimensions are less than about 1,000 nanometers.There is fairly widespread belief that these trends are likely to continue for more than another several years.


There are two concepts commonly associated with nanotechnology.


1.postional assembly


2.massive parellelism




Monday, March 9, 2009

applications of nanotechnology in various branches

In medicine
Researchers are developing customized nanoparticles the size of molecules that can deliver drugs directly to diseased cells in your body. When it's perfected, this method should greatly reduce the damage treatment such as chemotherapy does to a patient's healthy cells. Check out our Nanotech in Medicine page to see how nanotech is being used in medicine.
Nanomedicine refers to future developments in medicine that will be based on the ability to build nanorobots. In the future these nanorobots could actually be programmed to repair specific diseased cells, functioning in a similiar way to antibodies in our natural healing processes. Check out our Nanomedicine page for more information.
IN electronics
Nanotechnology holds some answers for how we might increase the capabilities of electronics devices while we reduce their weight and power consumption. Check out our Nanotech in Electronics page to see how nanotech is being used in electronics.
In space
Nanotechnology may hold the key to making space-flight more practical. Advancements in nanomaterials make lightweight solar sails and a cable for the space elevator possible. By significantly reducing the amount of rocket fuel required, these advances could lower the cost of reaching orbit and traveling in space
In Food
Nanotechnology is having an impact on several aspects of food science, from how food is grown to how it is packaged. Companies are developing nanomaterials that will make a difference not only in the taste of food, but also in food safety, and the health benefits that food delivers.

exponential proliferation of the technology

Nanotechnology not only will allow making many high-quality products at very low cost, but it will allow making new nanofactories at the same low cost and at the same rapid speed. This unique (outside of biology, that is) ability to reproduce its own means of production is why nanotech is said to be an exponential technology. It represents a manufacturing system that will be able to make more manufacturing systems—factories that can build factories—rapidly, cheaply, and cleanly. The means of production will be able to reproduce exponentially, so in just a few weeks a few nanofactories conceivably could become billions. It is a revolutionary, transformative, powerful, and potentially very dangerous—or beneficial—technology. How soon will all this come about? Conservative estimates usually say 20 to 30 years from now, or even much later than that. However, CRN is concerned that it may occur sooner, quite possibly within the next decade. This is because of the rapid progress being made in enabling technologies, such as optics, nanolithography, mechanochemistry and 3D prototyping. If it does arrive that soon, we may not be adequately prepared, and the consequences could be severe.
Nanotechnology offers great potential for benefit to humankind, and also brings severe dangers. While it is appropriate to examine carefully the risks and possible toxicity of nanoparticles and other products of nanoscale technology, the greatest hazards are posed by malicious or unwise use of molecular manufacturing. CRN's focus is on designing and promoting mechanisms for safe development and effective administration of MM.

it is a dual purpose technology

Like electricity or computers before it, nanotech will offer greatly improved efficiency in almost every facet of life. But as a general-purpose technology, it will be dual-use, meaning it will have many commercial uses and it also will have many military uses—making far more powerful weapons and tools of surveillance. Thus it represents not only wonderful benefits for humanity, but also grave risks. A key understanding of nanotechnology is that it offers not just better products, but a vastly improved manufacturing process. A computer can make copies of data files—essentially as many copies as you want at little or no cost. It may be only a matter of time until the building of products becomes as cheap as the copying of files. That's the real meaning of nanotechnology, and why it is sometimes seen as "the next industrial revolution.
The power of nanotechnology can be encapsulated in an apparently simple device called a personal nanofactory that may sit on your countertop or desktop. Packed with miniature chemical processors, computing, and robotics, it will produce a wide-range of items quickly, cleanly, and inexpensively, building products directly from blueprints.
Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced.
In its original sense, 'nanotechnology' refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products.
When K. Eric Drexler (right) popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nanometers wide—motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nanometer-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nanotech: their definition includes anything smaller than 100 nanometers with novel properties.
Much of the work being done today that carries the name 'nanotechnology' is not nanotechnology in the original meaning of the word. Nanotechnology, in its traditional sense, means building things from the bottom up, with atomic precision. This theoretical capability was envisioned as early as 1959 by the renowned physicist Richard Feynman.

Based on Feynman's vision of miniature factories using nanomachines to build complex products, advanced nanotechnology (sometimes referred to as molecular manufacturing) will make use of positionally-controlled mechanochemistry guided by molecular machine systems. Formulating a roadmap for development of this kind of nanotechnology is now an objective of a broadly based technology roadmap project led by Battelle (the manager of several U.S. National Laboratories) and the Foresight Nanotech Institute.
Shortly after this envisioned molecular machinery is created, it will result in a manufacturing revolution, probably causing severe disruption. It also has serious economic, social, environmental, and military implications.

what is nanotechnology?

So what exactly is nanotechnology? One of the problems facing nanotechnology is the confusion about its definition. Most definitions revolve around the study and control of phenomena and materials at length scales below 100 nm and quite often they make a comparison with a human hair, which is about 80,000 nm wide. Some definitions include a reference to molecular systems and devices and nanotechnology 'purists' argue that any definition of nanotechnology needs to include a reference to "functional systems". The inaugural issue of Nature Nanotechnology asked 13 researchers from different areas what nanotechnology means to them and the responses, from enthusiastic to sceptical, reflect a variety of perspectives.
It seems that a size limitation of nanotechnology to the 1-100 nm range, the area where size-dependant quantum effects come to bear, would exclude numerous materials and devices, especially in the pharamaceutical area, and some experts caution against a rigid definition based on a sub-100 nm size.
Another important criteria for the definition is the requirement that the nano-structure is man-made. Otherwise you would have to include every naturally formed biomolecule and material particle, in effect redefining much of chemistry and molecular biology as 'nanotechnology.'
The most important requirement for the nanotechnology definition is that the nano-structure has special properties that are exclusively due to its nanoscale proportions
As nanotechnology explodes, and as federal agencies wrangle over whose responsibility it is to deal with an essentially unregulated industry, it's all the more crucial to take stock of the emerging field as soon as possible.
"This is not a technology we want to say no to out of hand," says Jennifer Sass, a senior scientist at the Natural Resources Defense Council (NRDC). "I think this is a technology that is potentially transformative, but we want to use it in a way to take advantage of that while reducing the risk."
Maynard sees this moment as a crossroads for nanotechnology. "What concerns me," he says, "is that if we're not smart about this we'll get something wrong, which would cause unnecessary damage to the environment or to people and would undermine the potential of all nanotechnology."
Nowhere is the tension between real and perceived risk -- not to mention the tension between the mundane and the transformative -- more apparent than with nanosilver. Nanosilver offers an important early test case for two reasons: It is now used in more consumer products than any other nanomaterial, and it is principally designed for use in products that come into direct contact with the human body. Since late 2005, the Project on Emerging Nanotechnologies has been compiling an inventory of products that contain nanomaterials. In the first two years the list more than doubled, to more than 500 products as of the summer of 2007. Of these, nearly 100 contain nanosilver, almost always because of its antimicrobial action.
Nanotechnology, fast becoming a three-trillion-dollar industry, is about to revolutionize our world.
For an industry that trades in the very, very small, projections about the potential scope of nanotechnology are gigantic. Estimates are that the industry will grow at a staggering pace in its first decade, reaching close to $3 trillion globally by 2014. The National Nanotechnology Initiative, created by President Bill Clinton in 2000, has called it "the next industrial revolution." Enthusiasts say that nanotechnology may someday enable scientists to build objects from the atom up, leading to entirely new replacement parts for failing bodies and minds. It may enable engineers to make things that never existed before, creating nanosize "carpenters" that can be programmed to construct anything, atom by atom -- including themselves. Or it may make things disappear, with nanowires that get draped around an object in a way that makes the whole package invisible to the naked eye.
As difficult as it is to comprehend how huge is the promise of nanotechnology, it's just as hard to wrap your head around just how tiny "nano" is. A nanometer is defined as one billionth of a meter, but what does that mean? The analogies are mind-boggling but not necessarily enlightening. Hearing how small things are when you're working at the nano level doesn't help you visualize anything, exactly; all it does is make you sit back and say, "Wow." If you think of a meter as the earth, goes one analogy, then a nanometer would be a marble. If you think of a meter as the distance from the earth to the sun, then a nanometer would be the length of a football field. A nanometer is one hundred-thousandth the width of a human hair. Or it is, in a particularly kinetic description, the length that a man's beard will grow in the time it takes him to lift a razor to his face.
"Things get complex down there, in terms of the physics and the chemistry," says Andrew Maynard, chief science adviser for the Project on Emerging Nanotechnologies, established in 2005 at the Woodrow Wilson International Center for Scholars in Washington, D.C., in partnership with the Pew Charitable Trust. "When you have small blocks of stuff, they behave differently than when you have large blocks of stuff."
At the nano level, some compounds shift from inert to active, from electrical insulators to conductors, from fragile to tough. They can become stronger, lighter, more resilient. These transformed properties are what account for the infinite potential applications of nanoparticles, defined as anything less than about 100 nanometers in diameter.
The field is a textbook example of exponential growth. According to Lux Research, an emerging-technologies research and advisory firm based in New York that has tracked the industry since 2001, the total value of all products worldwide that incorporated nanotechnology was $13 billion in 2004. That figure grew to $32 billion in 2005 and to $50 billion in 2006, and Lux Research projects it will reach $2.6 trillion by 2014.
Nanotechnology holds great potential for improving our lives. It might benefit the environment, for instance, by reducing our dependence on oil through the creation of a new power grid based on carbon nanotubes -- which can carry up to 1,000 times as much electricity as copper wiring without throwing off heat -- and solar energy farms that use thin, cheap, flexible nano-engineered solar panels.
Nanostructures offer better options for rechargeable batteries, for instance, including the ones to be used in the next generation of hybrid cars. One such battery, made with nanostructured lithium-iron- phosphate electrodes, is smaller and lighter, less environmentally toxic, and can hold more energy, take a charge more quickly, and maintain a charge longer than conventional lithium batteries, according to Michael Holman, a senior analyst with Lux Research. "It's not the compound itself that's nanoscale, but the surface of the material," Holman says. The surface of the battery electrode contains nanosize bumps and ridges, "which make the surface area much higher, allowing the electrons to flow in and out of it more quickly."
In the medical field, nanotechnology is expected to lead to dozens of innovations: new methods of cancer treatment that deliver chemotherapy directly to the tumor, earlier cancer detection using nanowires that can spot derangements in just a few protein cells, new methods of blood vessel grafting during heart surgery using nanoglue formed from nanospheres of silica coated in gold.
In cancer treatment, one application involves gold nanoshells: gold-coated glass spheres no more than 100 nanometers in diameter. These nanoshells enter tumors by slipping through tiny gaps in blood vessels that feed the malignancy. Once enough nanoshells accumulate in the tumor, scientists shine a near-infrared laser through the skin, heating up the gold particles and burning away the cancer. This technique, developed at the University of Texas Health Science Center, has worked in animal experiments and is about to be used in humans.
However, the real impact of nanotechnology, at least in the short term, will not be at the dramatic level of cancer cures or a new energy grid. For now, the technology will have to prove itself in the more mundane arena of commerce: washing machines that fight germs, antiseptic computer keyboards and kitchen utensils, windshields that repel the rain, sunscreens that rub on easily and block the full spectrum of ultraviolet rays. Nanoparticles are being put into stain-resistant clothing (Haggar NanoTex pants with NANO-PEL), super light tennis rackets (Wilson nCode), antiwrinkle face creams (Lancôme Rénergie Microlift), sunscreens (Blue Lizard), computer peripherals (IOGEAR), and a wall paint made by an Australian company, Nanovations, that says the paint can "achieve better energy ratings for buildings, better indoor air quality and fewer allergy-related illnesses."
But before we hurtle off toward a nano-utopia, we need to step back and ask ourselves whether this is a direction in which we really want to go.
When an industry grows this quickly, there may be neither the time nor the inclination to ask some tough questions about possible risks. First of all, there are the health and environmental hazards. Would nanotechnology bring unacceptable risks to workers making these materials or consumers who use the final products? Would it affect air or water quality near where the nanomaterials are dispersed? Very little is known about nanotoxicology, which might be very different from the toxicology of the same materials at normal scale
Then there are the social, even existential, consequences. If the hype about nanotechnology contains even a smattering of truth, the technique could shake up our most basic assumptions about our place in the universe, turning us from its residents to the architects of its most fundamental elements. Might that act of hubris