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Current Nanotech News


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#31 randolfe

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Posted 08 April 2004 - 10:57 PM

Nanotech is not my strongest area of knowledge. However, it is interesting to see how those who are generally against genetic engineering, biotech patents, human cloning, etc. eagerly pile on to tout the "dangers" of nanotechnology and to try to stop research in the area.

In today's Wired internet news, there was an article about nanoparticles from buckey balls killing fish by invading their brains since the particles were so small they could just pass through cell walls, etc.

Article link:
http://www.wired.com...0.html/wn_ascii

#32 Lazarus Long

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Posted 09 April 2004 - 01:02 PM

This is the interface tech of nano-electronics and specific computer hardware advancement. NO it is not an "assembler" but it does represent another clear advance in precise control over molecular assembly and an ever more potentially complex and powerful product.

LL

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http://www.nytimes.c...its/08next.html
Refining Semiconductors, One Atom at a Time
By ANNE EISENBERG
Published: April 8, 2004

AT the heart of semiconductor fabrication are crucial additives called dopants. These impurities change the electronic properties of silicon or other material to make the transistors and other components of a chip.

Currently these dopants are added in bulk, their exact location usually no more a problem than the exact location of grains of baking soda or raisins stirred into cake batter.

But as electronic devices shrink - and the hope is to get them down to the size of a molecule - serious problems with doping are expected. At that small a scale, the location of a needed doping atom must be known exactly: the atom has to be present and countable on the molecule that is acting as, say, a diode.

Although electronic devices are not yet that small, problems have already arisen in controlling the number and location of dopants. A difference as fine as one atom of dopant or two can, for example, change the voltage at which a device switches.

But a physicist has succeeded in controlling doping precisely at the atomic level. Michael F. Crommie, a professor of physics of the University of California at Berkeley, has attached single dopant atoms, one by one, to single molecules, thereby custom-tailoring their electronic properties.

The work is significant because of the tight control it offers, possibly in designing molecules that will in the future become single circuit elements.

Dr. Crommie and his group took the probe of a homemade scanning tunneling microscope and moved large carbon molecules across a chilled silver surface toward atoms of dopant. The dopant, potassium, hopped onto the molecule, immediately changing its charge.

"This is the first time someone has been able to actually control doping on an atom-by-atom basis," said Jun Nogami, an associate professor of chemical engineering and materials science at Michigan State University.

Researchers have managed to put dopant atoms both inside nanotubes and inside the molecule Dr. Crommie used, but not with the same level of control.

"Dr. Crommie can add and subtract the atoms," Dr. Nogami said. "Therefore, in principle, he can tune the electronic structure to produce a particular device characteristic."

The Berkeley group worked with a well-known carbon molecule, named buckminsterfullerene because its geodesic shape resembles the domes devised by the architect Buckminster Fuller. This fullerene, also known as a buckyball, contains 60 carbon atoms. Researchers in molecular electronics hope that one day molecules like these may form the backbone of electronic devices.

In the experiment, reported in the journal Science, all of the work was done in a vacuum chamber at an icy 7 degrees Kelvin - very close to absolute zero.

"Cold is the name of this game," said Dr. Nogami. "Otherwise the atoms move around too much."

When the single atom of potassium attached to the molecule, it changed the molecule's electronic properties, donating a charge in what is known as N-type doping. "In this way," Dr. Crommie said, "we scale the idea of changing properties right down to the molecular level by adding or removing single doping atoms."

The researchers could reverse the process, too, by dragging the buckyball across an impurity in the silver crystal and removing the doping atom.

Dr. Crommie was able to add up to seven atoms to the molecule, one by one. "The buckyballs were like molecular Pac-Men," he said, "gobbling up the dopant atoms."

The buckyball retained its basic shape during the change, Dr. Crommie said. "With four potassium atoms added, for example, it was about 9 percent wider and 3 percent shorter." Still, its diameter was only about one nanometer, or a billionth of a meter.

The electronic changes that the molecules underwent during potassium doping were measured with the scanning tunneling microscope.

"It's so nice that you can see the energy levels of the molecules shift as he traps the potassium at the surface of the molecule," Max G. Lagally, a physicist and professor in the engineering college at the University of Wisconsin at Madison, said of Dr. Crommie's work.

Each potassium atom gave about six-tenths of the charge of an electron. Some of the charge was probably left behind on the silver substrate, Dr. Crommie said.

In the future, the Berkeley team's work might help others design molecules that have exactly the properties needed for circuit elements. For example, if a device were made of buckyballs, the addition or subtraction of dopant atoms could control the voltage at which the device switched.

Dr. Lagally said that Moore's Law, which predicts that the number of transistors on a chip will double every 18 months, has had many challenges, one of them the limits of doping. "It's a real showstopper," he said, because of the problems of knowing exactly where the dopants are when the process is done in bulk.

But Dr. Crommie has gotten around that problem. "Here he's demonstrated that the atom is on the buckyball, and he knows it's there," Dr. Lagally said.

Many approaches for altering molecules' electronic properties are being tried, including chemical synthesis and the use of electrodes as gates, and much work lies ahead to create molecular circuit elements.

"But this is a starting point," Dr. Lagally said.

E-mail: Eisenberg@nytimes.com

#33 chubtoad

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Posted 12 April 2004 - 11:36 PM

http://www.scienceda...40412013246.htm

Self-assembling 'Nanotubes' Offer Promise For Future Artificial Joints

WEST LAFAYETTE, Ind. - Tiny "nanotubes" that assemble themselves using the same chemistry as DNA could be ideal for creating better artificial joints and other body implants.

Researchers at Purdue University, the University of Alberta and Canada's National Institute for Nanotechnology have discovered that bone cells called osteoblasts attach better to nanotube-coated titanium than they do to conventional titanium used to make artificial joints.

"We have demonstrated the same improved bone-cell adhesion with other materials, but these nanotubes are especially promising for biomedical applications because we'll probably be able to tailor them for specific parts of the body," said Thomas Webster, an assistant professor of biomedical engineering at Purdue.

Findings are detailed in a paper appearing in the April issue of Nanotechnology, published by the Institute of Physics in the United Kingdom. The paper was written by Purdue biomedical engineering doctoral student Ai Lin Chun, Purdue chemistry doctoral student Jesus G. Moralez, Webster and Hicham Fenniri, a professor of chemistry at the University of Alberta and senior research officer at the Canadian nanotechnology institute, where Chun and Moralez are doctoral students as well.

The self-assembling nanotubes were developed by Fenniri while he was an assistant professor at Purdue.

Webster has shown in a series of experiments that bone cells and cells from other parts of the body attach better to various materials that possess surface bumps about as wide as 100 nanometers, or billionths of a meter.

Conventional titanium used in artificial joints has surface features on the scale of microns, or millionths of a meter, causing the body to recognize them as foreign and prompting a rejection response. The body's rejection response eventually weakens the attachment of the implants and causes them to become loose and painful, requiring replacement surgery.

The nanometer-scale bumps mimic surface features of proteins and natural tissues, not only prompting cells to stick better but promoting the growth of new cells. Bone and other tissues adhere to artificial body parts by growing new cells that attach to the implants, so the experiments offer hope in developing longer lasting and more natural implants, Webster said.

Now researchers have discovered that the self-assembling nanotubes represent an entirely new and potentially superior material to use for artificial body parts.

Fenniri created the self-assembling structures by using the chemistry of deoxyribonucleic acid, or DNA, to make a series of molecules that are "programmed" to link in groups of six to form tiny rosette-shaped rings. Numerous rings then combine to create the rod-like nanotubes, which have widths of only about 3.5 nanometers.

"He had these nice nanotubes, and I had this work that showed nice bone synthesis and other tissue regeneration on nanomaterials, so we said, 'Wouldn't it be great to actually combine the two to see if his material can promote new bone growth with these nanotubes?'" Webster said.

One nanometer is roughly the length of 10 hydrogen atoms strung together. A human hair is more than 30,000 times wider than the rosette nanotubes used in the study.

Self-assembly is a well-known principle in biology in which the right mix of molecules interact on their own to form distinctive structures ranging from DNA to cells and organs. The rosette-shaped rings are made of guanine and cytosine, which are molecules called "base pairs" that come together to form DNA.

In addition to possible biomedical applications, the nanotubes offer promise in the design of future materials, electronic devices and drug delivery systems.

The researchers coated titanium with the nanotubes and placed them in Petri plates containing a liquid suspension of bone cells colored with a fluorescent dye. After a few hours, the nanotube-coated titanium was washed, and a microscope was used to count how many of the dyed osteoblasts adhered to the material. Out of 2,500 bone cells in the suspension, 2,300 to 2,400 were found to adhere to the nanotube-coated metal. That compares with about 1,500 cells adhering to titanium not coated with the nanotubes, representing an increase of about one-third.

The quick attachment of bone cells is critical to create a solid bond between orthopedic implants and the body's natural bone. The same applies to artificial parts transplanted in other parts of the body, such as arteries and the brain.

"The reason we are so excited is that we see improved osteoblast function on the coated titanium compared to the plain titanium," Webster said.

Webster has found similar results with other materials that possess the nano-scale surface bumps, such as ceramics, metals and nanotubes made of carbon. The rosette nanotubes, however, may provide a major advantage over those materials, he said.

Protein components, such as "signaling peptides," or amino acids, such as lysine and arginine, can be easily attached to the surface of the nanotubes, making it feasible to tailor the nanotubes so that they are recognized by specific cells and body parts.

"There are definite amino acid sequences that bone cells recognize and stick to," Webster said. "One of those sequences is arginine, glycine and aspartic acid. There is a lot of work in the field now to incorporate this sequence into materials.

"One of the other reasons we were so excited about this is that we can put this sequence on these tubes."

Attaching the sequence of amino acids onto the nanotubes will likely increase osteoblast adhesion even more, Webster said.

Various parts of the body recognize and attach to different sequences.

"I think this really points to strong biomedical applications," Webster said. "If the cells you are targeting respond to protein sequence XYZ, you just put that sequence on the nanotubes and you can promote this attachment."

Another finding in the research is that low concentrations of the nanotubes provide the same results as higher concentrations.

"That means you can use very low concentrations of this and still get statistically higher bone-cell attachment," Webster said. "So it's cheap. You don't need a lot of it to get the effect that you want."

Unlike other nano-scale materials Webster has worked with, the rosette nanotubes automatically arrange themselves into a webbed pattern on the surface of the titanium. The pattern resembles those seen by natural collagen fibers in bones and other tissues.

Future work will focus on further modifying the nanotubes and conducting additional experiments.

The need for better technology is growing as more artificial body parts are used, Webster said.

For example, about 152,000 hip replacement surgeries were performed in the United States in 2000, representing a 33 percent increase from 1990. The number of hip replacements by 2030 is expected to grow to 272,000 in this country alone because of aging baby boomers.



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#34 randolfe

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Posted 21 April 2004 - 11:21 PM

There is an article from the Associated Press which was carried in Wired News today regarding the possible vulnerability of the internet to hackers.

I'd do a Lazarus Long and print the entire article here but I think it will be indexed and reachable at this address for some time:

http://go.hotwired.c...0.html/wn_ascii

The Associated News is known in publishing for being extremely proprietary about anything that they publish. I'd push the limits with others but not with them.

#35 chubtoad

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Posted 22 April 2004 - 08:56 PM

http://www.scienceda...40421234914.htm

Ultra-fast Laser Allows Efficient, Accessible Nanoscale Machining

ANN ARBOR, Mich. -- Think of a microscopic milling machine, capable of cutting just about any material with better-than-laser precision, in 3-D -- and at the nanometer scale.

In a paper published this week in the Proceedings of the National Academy of Sciences, University of Michigan researchers explain how and why using a femtosecond pulsed laser enables extraordinarily precise nanomachining. The capabilities of the ultra-fast or ultra-short pulsed laser have significant implications for basic scientific research, and for practical applications in the nanotechnology industry.

Initially, the researchers working at the Center for Ultrafast Optical Science wanted to use the ultra-fast laser as a powerful tool to study structures within living cells, said Alan Hunt, assistant professor, Department of Biomedical Engineering.

"It turned out we could push much farther than expected and the applications became broad, from microelectronics applications to MEMS (microelectromechanical systems) to microfluidics," Hunt said. One of the most perplexing problems in nanotechnology is finding an efficient and precise way to build and machine the tiny devices. For example, a human hair is about 100,000 nanometers across.

The unique physics of an ultra-short pulsed laser used at a very high intensity make it possible to selectively ablate or cut away features as small as 20 nanometers, Hunt said. This is possible because of the unique physics of how extremely short pulses of light interact with matter; specifically using femtosecond pulses, a blast of light just a quadrillionth of a second long.

Currently, there is no easy way to machine a wide variety of materials on the nanometer scale, Hunt said, and the technique with capabilities closest to the ultrafast laser is electron beam lithography. Even this approach does not allow machining below the surface or within a material.

Photolithography, the technique used to make computer chips, is used to do such machining on a larger scale but is difficult to get to the nanometer scale, requires specific materials and can generally only be used on one plane. For example, that means that channels on a chip cannot cross without mixing, placing a severe constraint on the microfluidics and "lab on a chip" designs.

But the unique physics of the femtosecond pulse allows machining in 3-D, Hunt said.

"If we have three channels on a plane, we can link the outer two without cutting into the center one, we can go down over and up, we can cut a U-shape," Hunt said. "Not being constrained to one plane, the level of complexity that can be achieved is much greater."

The research team included Hunt; Gerard Mourou, professor of electrical engineering and computer science; Ajit Joglekar, who recently completed his doctorate in biomedical engineering; Hsiao-hua Liu, a post doc at the Center for Ultrafast Optical Science; and Edgar Meyhofer, associate professor of biomedical engineering and mechanical engineering.



#36 chubtoad

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Posted 27 April 2004 - 09:03 AM

http://www.sciencene...040424/fob2.asp

Photovoltaic Cells

In ordinary photovoltaic cells, lots of sunlight goes to waste as it heats up the cell. New results suggest that solar cells made from nanocrystals can trade this wasteful heating for an electricity-generating boost.

Theoretical calculations indicate that nanocrystal-based solar cells could convert 60 percent of sunlight into electricity, say Richard D. Schaller and Victor I. Klimov of Los Alamos (N.M.) National Laboratory. The best solar cells today operate at an efficiency of about 32 percent.

Schaller and Klimov describe their results, the first observations of a long-sought cue ball effect in nanometer-scale crystals, in an upcoming Physical Review Letters.

The work is "an important scientific advance," says Arthur J. Nozik of the National Renewable Energy Laboratory in Golden, Colo. He was the first scientist to propose that nanocrystals, sometimes called quantum dots (SN: 3/6/04, p. 157: Available to subscribers at http://www.sciencene...306/note13.asp), might exhibit the effect, called impact ionization.

Nozik leads a team that has sought the elusive effect for 6 years. Now, it appears that the Los Alamos researchers have reached the goal first. "We're kind of chagrined," Nozik admits.

In silicon or other semiconductor materials typically used for solar cells, electrons require a minimum energy to break free from atoms and join an electric current. Most often, electrons get that energy kick from solar photons that pack more than that minimum energy.

The nanocrystal findings show that the outcome of the extra energy depends in part on the size of the crystal that absorbs an incoming photon, Klimov says.



#37 chubtoad

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Posted 28 April 2004 - 05:20 PM

http://www.scienceda...40428061542.htm

Diagnostic Method Based On Nanoscience Could Rival PCR

EVANSTON, Ill. --- Since the advent of the polymerase chain reaction (PCR) nearly 20 years ago, scientists have been trying to overturn this method for analyzing DNA with something better. The "holy grail" in this quest is a simple method that could be used for point-of-care medical diagnostics, such as in the doctor's office or on the battlefield.

Now chemists at Northwestern University have set a DNA detection sensitivity record for a diagnostic method that is not based on PCR -- giving PCR a legitimate rival for the first time. Their results were published online today (April 27) by the Journal of the American Chemical Society (JACS).

"We are the first to demonstrate technology that can compete with -- and beat -- PCR in many of the relevant categories," said Chad A. Mirkin, director of Northwestern's Institute for Nanotechnology, who led the research team. "Nanoscience has made this possible. Our alternative method promises to bring diagnostics to places PCR is unlikely to go -- the battlefield, the post office, a Third World village, the hospital and, perhaps ultimately, the home."

The new selective and ultra-sensitive technology, which is based on gold nanoparticles and DNA, is easier to use, considerably faster, more accurate and less expensive than PCR, making it a leading candidate for use in point-of-care diagnostics. The method, called bio-bar-code amplification (BCA), can test a small sample and quickly deliver an accurate result. BCA also can scan a sample for many different disease targets simultaneously.

The Northwestern team has demonstrated that the BCA method can detect as few as 10 DNA molecules in an entire sample in a matter of minutes, making it as sensitive as PCR. The technology is highly selective, capable of differentiating single-base mismatches and thereby reducing false positives.

In their experiments, the scientists used the anthrax lethal factor, which is important for bioterrorism and has been well studied in the literature, as their target DNA.

The BCA approach builds on earlier work reported last September in the journal Science where Mirkin and colleagues used BCA to detect proteins, specifically prostate specific antigen, at low levels.

For the DNA detection, the team used commercially available materials to outfit a magnetic microparticle and a gold nanoparticle each with a different oligonucleotide, a single strand of DNA that is complementary to the target DNA. When in solution, the oligonucleotides "recognize" and bind to the DNA, sandwiching the DNA between the two particles.

Attached to each tiny gold nanoparticle (just 30 nanometers in diameter) are hundreds to thousands of identical strands of DNA. Mirkin calls this "bar-code DNA" because they have designed it as a unique label specific to the DNA target. After the "particle-DNA-particle" sandwich is removed magnetically from solution, the bar-code DNA is removed from the sandwich and read using standard DNA detection methodologies.

"For each molecule of captured target DNA, thousands of bar-code DNA strands are released, which is a powerful way of amplifying the signal for a DNA target of interest, such as anthrax," said Mirkin, also George B. Rathmann Professor of Chemistry. "There is power in its simplicity."

The technology could be commercially available for certain diseases in one year, Mirkin said.



#38 chubtoad

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Posted 29 April 2004 - 12:53 AM

http://www.nature.co.../040426-12.html
HELEN R. PILCHER

Could nanomachines be tomorrow's doctors?

Scientists have built a tiny biological computer that might be able to diagnose and treat certain types of cancer. The device, which only works in a test-tube, is years from clinical application. But researchers hope it will be the precursor of future 'smart drugs' that roam the body, fixing disease on the spot.

Instead of silicon chips and electrical circuits, the miniscule machine is made of DNA. And rather than being controlled by electrical signals, it senses changes in its environment and responds by releasing biological molecules.

The biocomputer senses messenger RNA, the DNA-like molecule that helps create proteins from the information in genes. In particular, it can detect the abnormal messenger RNAs produced by genes involved in certain types of lung and prostate cancer.

When the computer senses one of these RNAs it releases an anticancer drug, also made of DNA, which damps expression of the tumour-related gene, researchers report in Nature1.

Billions of the computers can be packed into a single drop of water, so they could easily fit inside a human cell. "It is decades off, but future generations of DNA computers could function as doctors inside cells," says Ehud Shapiro from the Weizmann Institute of Science, Israel, who led the research. The idea is they could diagnose disease from within cells and dispense drugs as necessary.

Fantastic voyage

"It is a little early to start thinking about applications," cautions DNA computer expert Lloyd Smith from the University of Wisconsin, Madison. "But it is an important conceptual leap." DNA computers are not new but this is the first in which both input and output are biological, which means it can be hooked up to living systems.

So far, the computer only works in the confines of a finely balanced salt solution, and there are many hurdles to overcome before it can be applied to real disease. It is necessary to ensure that the computers will survive inside a biological setting, will not provoke an immune response and will be safe to use, says Shapiro.

They would also need to be far more complex than the prototype, which recognizes only messenger RNAs related to cancer. And they would need to deliver a wide variety of drugs, not just DNA therapies. They would need to be tested in cell suspensions, tissue cultures, simple organisms, mammals and finally humans.

But if such hurdles could be overcome, then "it could be the killer application for DNA computing", says Smith. The idea is not a million miles from the 1966 film Fantastic Voyage, where a surgical team is miniaturized and inserted into a dying man.

Research like this is the interface between real science and "off the wall" science fiction, says Smith. "It is where science fiction is driving technology."



#39 chubtoad

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Posted 30 April 2004 - 01:48 AM

http://www.ornl.gov/...r=mr20040427-00

ORNL’s nanobiosensor technology gives new access to living cell’s molecular processes

OAK RIDGE, Tenn., April 27, 2004 — Researchers at the Department of Energy's Oak Ridge National Laboratory have developed a nanoscale technology for investigating biomolecular processes in single living cells. The new technology enables researchers to monitor and study cellular signaling networks, including the first observation of programmed cell death in a single live cell.

The "nanobiosensor" allows scientists to physically probe inside a living cell without destroying it. As scientists adopt a systems approach to studying biomolecular processes, the nanobiosensor provides a valuable tool for intracellular studies that have applications ranging from medicine to national security to energy production.

ORNL Corporate Fellow and Life Sciences Division researcher Tuan Vo-Dinh leads a team of researchers who are developing the nanoscale technology. "This research illustrates the integrated ‘nano-bio-info' approach to investigating and understanding these complex cell systems," Vo-Dinh said. "There is a need to explore uncharted territory inside a live cell and analyze the molecular processes. This minimally invasive nanotechnology opens the door to explore the inner world of single cells".

ORNL's work was most recently published in the Journal of the American Chemical Society and has appeared in a feature article of the journal Nature. Members of Vo-Dinh's research team include postdoctoral researchers Paul M. Kasili, Joon Myong Song and research staff biochemist Guy Griffin.

The group's nanobiosensor is a tiny fiber-optic probe that has been drawn to a tip of only 40 nanometers (nm) across—a billionth of a meter and 1,000 times smaller than a human hair. The probe is small enough to be inserted into a cell.

Immobilized at the nanotip is a bioreceptor molecule, such as an antibody, DNA or enzyme that can bind to target molecules of interest inside the cell. Video microscopy experiments reveal the minimally invasive nature of the nanoprobe in that it can be inserted into a cell and withdrawn without destroying it.

Because the 40-nm diameter of the fiber-optic probe is much narrower than the 400-nm wavelength of light, only target molecules bound to the bioreceptors at the tip are exposed to and excited by the evanescent field of a laser signal.

"We detect only the molecules that we target, without all the other background ‘noise' from the myriad other species inside the cell. Only nanoscale fiber-optics technology can provide this capability," said Vo-Dinh.

ORNL's technology gives molecular biologists an important systems biology approach of studying complex systems through the nano-bio-info route. Conventional analytical methods—electron microscopy or introducing dyes, for example—have the disadvantage of being lethal to the cell.

"The information obtained from conventional measurements is an average of thousands or millions of cells," said Vo-Dinh. "When you destroy cells to study them, you can't obtain the dynamic information from the whole live cell system. You get only pieces of information. Nanosensor technology provides a means to preserve a cell and study it over time within the entire cell system."

The ability to work with living cells opens a new path to obtaining basic information critical to understanding the cell's molecular processes. Researchers have a new tool for understanding how toxic agents are transported into cells and how biological pathogens trigger biological responses in the cell.

Vo-Dinh's team recently detected the biochemical components of a cell-signaling pathway, apoptosis. Apoptosis is a key process in an organism's ability to prevent disease such as cancer. This programmed cell-death mechanism causes cells to self-destruct before they can multiply and introduce disease to the organism.

"When a cell in our body receives insults such as toxins or inflammation and is damaged, it kills itself. This is nature's way to limit and stop propagation of many diseases such as cancer," said Vo-Dinh. "For the first time we've seen apoptosis occur within a single living cell."

Apoptosis triggers a host of tell-tale enzyme called caspases. Vo-Dinh's team introduced a light-activated anti-cancer drug into cancer cells. They then inserted the fiberoptic nanoprobe with a biomarker specific for caspase-9 attached to its tip. The presence of caspase-9 caused cleavage of the biomarker from the tip of the nanobiosensor. Changes in the intensity of the biomarker's fluorescence revealed that the light-activated anti-cancer drug had triggered the cell-death machinery.

"The nanobiosensor has many other applications for looking at how cells react when they are treated with a drug or invaded by a biological pathogen. This has important implications ranging from drug therapy development to national security, environmental protection and a better understanding of molecular biology at a systems level," said Vo-Dinh. "This area of research is truly at the nexus of nanotechnology, biology and information technology."



#40 chubtoad

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Posted 30 April 2004 - 07:58 PM

http://www.lbl.gov/S...or-nanoage.html

A Conveyor Belt for the Nano-Age

In a development that brings the promise of mass production to nanoscale devices, Lawrence Berkeley National Laboratory scientists have transformed carbon nanotubes into conveyor belts capable of ferrying atom-sized particles to microscopic worksites.
 
Someday, nanoscale conveyor belts could expedite the atom-by-atom construction of the world’s smallest devices (courtesy of Zettl Research Group). 
 
By applying a small electrical current to a carbon nanotube, they moved indium particles along the tube like auto parts on an assembly line. Their research, described in the April 29 issue of Nature, lays the groundwork for the high-throughput construction of atomic-scale optical, electronic, and mechanical devices that will power the burgeoning field of nanotechnology.

“We’re not transporting atoms one at a time anymore — it’s more like a hose,” says Chris Regan of Berkeley Lab’s Materials Sciences Division, who co-authored the article along with fellow Materials Sciences researchers Shaul Aloni, Ulrich Dahmen, Robert Ritchie, and Alex Zettl. Aloni, Regan, and Zettl are also scientists in the University of California at Berkeley’s Department of Physics, where much of the work was conducted.

The ability to shuttle a stream of particles to precise locations fills a void that has stymied the efficient assembly of nanostructures. For years, scientists have been able to simultaneously deliver millions of atoms to millions of sites simply by mixing chemicals. Although this fast technique has grown quite sophisticated, it remains far too blunt to build atomic-scale devices. On the other end of the spectrum is the ability to manipulate individual atoms, a feat that came of age in 1990 when IBM researchers spelled out the company logo by positioning 35 xenon atoms with a scanning tunneling microscope. Although precise, this technique is painstakingly slow, with no way to swiftly deliver atoms to the work area.

“It’s either all at once, or excruciatingly serial,” says Regan. “So we combined incredibly precise localization with something that has higher throughput.”

This middle ground is made possible by carbon nanotubes, which are hollow cylinders of pure carbon about ten thousand times smaller than the diameter of a human hair. Since their discovery in the sooty residue of vaporized carbon rods, these incredibly strong and versatile macromolecules have been engineered into frictionless bearings, telescoping rods, and the world's smallest room-temperature diodes. Now, they’re poised to change the way these and other devices are constructed.
 
As described in their Nature article, the research team thermally evaporated indium metal onto a bundle of carbon nanotubes. The amount of evaporated metal is so small it populates the tubes’ surfaces as isolated indium crystals, instead of uniformly coating them. The bundle is then placed inside a transmission electron microscope, where a tungsten tip mounted on the end of a nanomanipulator approaches one nanotube. After physical contact is made between the tip and the free end of the nanotube, voltage is applied between the tip and the other end of the nanotube, creating a circuit. This sends an electrical current through the nanotube, which generates thermal energy that heats the indium particles.

Next, if the voltage and thermal energy is carefully controlled, something strange occurs. Real-time video of the nanotube’s surface captures an indium particle as it disappears, while the particle to its right grows. Several seconds later, that newly enlarged particle also disappears, replaced by another even further to the right. Like squeezing the last bits of toothpaste from a tube, particles to the left become smaller while those to the right grow.

In this manner, the thermally driven indium atoms inchworm along the nanotube, momentarily occupying a reservoir where a particle is located, and then moving to the next, until all of the indium piles up at the end of the nanotube. In the future, this nano-sized conveyor belt could be aimed anywhere scientists want to deliver mass atom-by-atom — the makings of a formidable nanoassembly tool. Moreover, if the voltage is slightly increased, the indium’s temperature increases, and the metal moves from left to right more quickly.

“It’s the equivalent of turning a knob with my hand and taking macroscale control of nanoscale mass transport,” Regan says. “And it’s reversible: we can change the current’s polarity and drive the indium back to its original position.”

In other words, indium can be repeatedly moved back and forth along the nanotube without losing a single atom. Nothing is lost in transit. This conservation of mass occurs because the atoms don’t evaporate from the system during their journey — an advantage in any process meant to deliver valuable material to a worksite. Instead, the atoms hug the nanotube’s surface as they move, tethered by a process called surface diffusion.

“In order to build a structure we have to be able transport material to the construction site, and we’re developing a better way to do that,” Regan says. “Our nanoscale mass delivery system is simple and reversible. It requires only a nanotube, a voltage source, and something to transport.”

"Carbon Nanotubes as Nanoscale Mass Conveyors," by Chris Regan, Shaul Aloni, Robert Ritchie, Ulrich Dahmen, and Alex Zettl, appears in the April 29, 2004 issue of Nature.



#41 Jay the Avenger

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Posted 06 May 2004 - 05:03 PM

http://www.ananova.c...nceanddiscovery

Microscopic robot takes first steps

A microscopic robot that walks on two legs made from strands of DNA has taken its first steps.

The "nanowalker" is being hailed as a major breakthrough by scientists learning how to manipulate molecules.

Each of the walker's legs is made from two strands of DNA that pair up to form a short double helix.

A springy portion of each DNA strand runs across from the left to the right leg forming a bridge between them at the top.

At the bottom, one of the two strands pokes out of the helix to serve as a sticky "foot".

The robot walks along a track or "footpath" that is also made of DNA and covered in spikes to provide footholds.

By controlling the way the feet attach or detach from the track, the robot can be made to move forwards or backwards, New Scientist magazine reported.

The nanowalker's inventors, New York University chemists Nadrian Seeman and William Sherman, confirmed that the device had taken its first steps by using a DNA "fingerprint" technique to determine where its feet were.

Mobile microscopic robots will be needed if nanoscale manufacturing is to become a realistic prospect. They could be used to assemble other nanomachines and move useful molecules and atoms around.

US nanotechnology pioneer Bernard Yuke, from Bell Labs in New Jersey, said of the breakthrough: "It's an advance on everything that has gone before."


This is cool man!

A while ago, you'd only hear about rotating nano-motors. Today, we have invented a nano-elevator and a nanowalker in short succession!

#42 chubtoad

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Posted 12 May 2004 - 12:14 AM

http://news-info.wus...normal/848.html

Chemist's technique enables creation of novel carbon nanoparticles

May 4, 2004 — Using a technique pioneered by Washington University in St. Louis chemist Karen Wooley, Ph.D., scientists have developed a novel way to make discrete carbon nanoparticles for electrical components used in industry and research.

A technique developed by Karen Wooley has proved vital in the creation of novel carbon nanoparticles with colleagues at Carnegie Mellon University.
The method uses polyacrylonitrile (PAN) as a nanoparticle precursor and is relatively low cost, simple and potentially scalable to commercial production levels. It provides significant advantages over existing technologies to make well-defined nanostructured carbons. Using the method, PAN copolymers serving as carbon precursors can be deposited as thin films on surfaces (for example, silicon wafers), where they can be patterned and further processed using techniques currently employed to fabricate microelectronic devices. Such a seamless manufacturing process is important to generate integrated devices and would be difficult to achieve with other methods currently used to synthesize nanostructured carbons, said Tomasz Kowalewski, Ph.D., assistant professor of chemistry at the Mellon College of Science and principal investigator on this research.



#43 chubtoad

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Posted 20 May 2004 - 10:42 PM

http://www.eurekaler.../technology.php

Magnetic forces may turn some nanotubes into metals

Research documents first instance of band-gap shrinkage in a semiconductor
HOUSTON, May 21, 2004 -- A new study, published in today's issue of the journal Science, finds that the basic electrical properties of semiconducting carbon nanotubes change when they are placed inside a magnetic field. The phenomenon is unique among known materials, and it could cause semiconducting nanotubes to transform into metals in even stronger magnetic fields.
Scientists found that the "band gap" of semiconducting nanotubes shrank steadily in the presence of a strong magnetic force, said lead researcher Junichiro Kono, an assistant professor of electrical and computer engineering at Rice University. The research, which involved a multidisciplinary team of electrical engineers, chemists and physicists, helps confirm quantum mechanical theories offered more than four decades ago, and it sheds new light on the unique electrical properties of carbon nanotubes, tiny cylinders of carbon that measure just one-billionth of a meter in diameter.

"We know carbon nanotubes are exceptionally strong, very light and imbued with wonderful electrical properties that make them candidates for things like 'smart' spacecraft components, 'smart' power grids, biological sensors, improved body armor and countless other applications," said paper co-author Richard Smalley, director of Rice's Carbon Nanotechnology Laboratory. "These findings remind us that there are still unique and wonderful properties that we have yet to uncover about nanotubes."

By their very nature, semiconductors can either conduct electricity, in the same way metals do, or they can be non-conducting, like plastics and other insulators. This simple transformation allows the transistors inside a computer to be either "on" or "off," two states that correspond to the binary bits -- the 1's and 0's -- of electronic computation.

Semiconducting materials like silicon and gallium arsenide are the mainstays of the computer industry, in part because they have a narrow "band gap," a low energy threshold that corresponds to how much electricity it takes to flip a transistor from "off" to "on."

"Among nanotubes with band gaps comparable to silicon and gallium arsenide, we found that the band gap shrank as we applied high magnetic fields," said physicist Sasa Zaric, whose doctoral dissertation was based upon the work. "In even stronger fields, we think the gap would disappear altogether."

Nanotubes, hollow cylinders of pure carbon that are just one atom thick, come in dozens of different varieties, each with a subtle difference in diameter or physical structure. Of these varieties roughly one third are metals and the rest are semiconductors.



#44 Mind

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Posted 06 June 2004 - 01:45 PM

The following link is to a long list of short articles. It is the EETimes mid-year forecast. It is a collection of what many CEO's in the computer industry see coming for the rest of this year and beyond. A lot of the writings deal with nanotechnology. It is mostly geared toward electrical engineers. I am not an engineer but still found a lot of the comments interesting.

EETimes mid-year forecast

One particular article that was interesting is A nano-bio future

Here is an excerpt

...the industry as a whole is at an inflection point, looking for the new "killer app" to grow it to the next level, or at least to regain those enjoyed in the late 1990s.

To some extent, the U.S. government is aiding in this quest by spending billions of dollars for research in nano- and biotechnologies for defense and homeland security. Moving to sub-50-nanometer geometries will create new opportunities for many companies. Sub-50-nm geometries will enable cost-effective devices that will be deployed in the billions (not millions) each year.

In the next decade, the average person will have hundreds of system-on-chip (SoC) devices either on them or very near them at any given moment. Such devices will weigh next to nothing and require very little power, but they will have a huge functionality impact.

What all this means is that the semiconductor industry must figure out new and innovative ways to develop multibillion-gate devices with power dissipation of less than 1 milliwatt. The resulting systems will not require such things as cooling fans, because new nano-bio cooling technologies will make fans as archaic as the old icebox of the 1920s. By the same token, a battery charge will last for years, not hours. What's more, rather than simply plugging them into a wall socket, users will be able to recharge them using solar, thermal and kinetic power.

The deployment of nano-biotechnology will also have a positive effect on the semiconductor intellectual-property business. As these SoCs are developed, several hundred IP blocks may be needed to complete a single design.



#45 kevin

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Posted 07 June 2004 - 06:57 PM

Link: http://www.nytimes.c...artner=MOREOVER


Nanotech Memory Chips Might Soon Be a Reality
By BARNABY J. FEDER
Published: June 7, 2004


Posted ImageLSI Logic will produce carbon nanotube chips at its semiconductor factory in Gresham, Ore. Commercial distribution could begin next year, the company said

Nantero, a start-up developing memory chips using nanotechnology, and LSI Logic, a leading maker of specialty microchips, are expected to announce today that they have transferred Nantero's technology to a standard semiconductor production line.

Nantero is creating NRAM, a high-density nonvolatile random access memory chip, which it hopes will replace existing forms of memory. Its technology, using cylindrical molecules of carbon known as nanotubes, will be used on a production line in LSI's semiconductor factory in Gresham, Ore.

Carbon nanotubes are among the new forms of carbon, known as fullerenes, whose discovery helped ignite interest in manipulation of materials at the molecular level, the field known as nanotechnology. Fullerenes consist of carbon atoms arranged in patterns resembling the nodes of the geodesic domes designed by Buckminster Fuller. Nanotubes, which researchers first created in 1991, consist of single- or multiwalled cylinders that can be less than 10 nanometers wide. A nanometer is one-billionth of a meter.

The transition from laboratory to production line took more than nine months, the companies said, adding that considerable work remains to improve the chips.

"But it's following the same type of road map as any other semiconductor product," said Norman L. Armour, vice president and general manager of the LSI factory in Gresham. Mr. Armour said that processors embedded with carbon nanotube memories in place of static random access memory, or SRAM, could be supplied commercially from the factory's pilot line next year if no problems developed.

If so, analysts said, such devices could emerge as one of the first products to exploit something other than the extraordinary strength of carbon nanotubes.

The nanotubes are up to 100 times as strong as steel and one-sixth its weight, qualities that have quickly led to their use in products like tennis rackets and automotive plastics, where they are mixed with other materials to improve their performance.

Researchers have also shown that the nanotubes have extraordinary electrical and magnetic characteristics. Recent reports, for example, have highlighted their ability to be quickly altered from metal-like conductors into semiconductors and back by applying magnetic fields.

Such novel qualities have helped make them a powerful symbol of nanotechnology's potential, but except as strengtheners nanotubes have proved difficult to bring to market. The challenges have included preventing clumping and the tendency of the simplest manufacturing approaches to produce mixes of single-walled and multiwalled tubes with varying characteristics.

Nantero's design applies charges to groups of single-walled nanotubes suspended over an electrode. Applying opposite charges to the tubes and the electrode causes the tubes to bend down, creating a junction that represents a 1. Applying like charges forces them apart into the 0 state. As with all digital memory, NRAM stores data as a pattern of 1's and 0's.

Carbon nanotube memories could sharply improve the performance of cellphones, laptop computers and other electronic devices. Like today's flash and SRAM memories, carbon nanotube designs can maintain data when power is turned off, an advantage over dynamic random access memory, or DRAM, memory chips, which must constantly be refreshed. But it can operate considerably faster and on less power than flash memory, and is much cheaper and more compact than SRAM.

Analysts caution that Nantero's carbon nanotubes face plenty of competition. Memories that hold their charge are crucial to improving the performance and design flexibility of a wide range of electronic products, and thus have become the most profitable and fastest-growing segment of the $35 billion memory market, according to Radu Andrei, a Web-Feet Research analyst based in Dallas. That is attracting heavy investment in technologies that could replace flash and SRAM.

"I count around 30 technology variations trying to get a piece of that pie," Mr. Andrei said. Among them are I.B.M., Intel, Motorola and numerous start-ups. Flash memory is now so inexpensive, he added, that innovators will have a hard time displacing it from all but the most demanding applications even if they surpass it technically.

#46 kevin

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Posted 07 June 2004 - 07:00 PM

Link: http://news.com.com/...=feed&subj=news


Reinventing the lightbulb, with nanotubes
Last modified: June 4, 2004, 1:19 PM PDT
By Michael Kanellos
Staff Writer, CNET News.com


Someday, carbon could light up your house.

Researchers at China's Tsinghua University and at Louisiana State University have developed a prototype lightbulb that replaces the standard tungsten filament in lightbulbs with a carbon nanotube.

The nanotube bulb uses less electricity and burns brighter than conventional bulbs. Theoretically, this could lead to the first major overhaul in the design of lightbulbs in more than a century. The results were published in Applied Physics Letters and reported first by PhysicsWeb.

Carbon nanotubes are emerging as one of the miracle materials for the future. Stronger than steel and better at conducting electricity than most metals, the tubes--made up of hexagons of carbon--could eventually be used to create dense memory chips; stronger aircraft parts; and lighter, more efficient electrical power lines, researchers believe.

Because of the complexity of manufacturing and manipulating nanotubes, most of the potential applications listed above won't appear for years, if ever. Still, some companies are already starting to incorporate nanotubes into polymers and coatings to create stronger plastic panels and noncorrosive paints.

Jinquan Wei at Tsinghua, and Bingqing Wei, a Tsinghua alum working at LSU, soaked bundles of nanotubes in an alcohol solution and assembled the tubes into long filaments. The two then replaced a tungsten filament in an ordinary 40-watt bulb with the carbon one.

Among other findings, the team determined that the carbon filament would begin to emit light at a lower voltage threshold, 3 to 5 volts versus 6 volts. They also found that the bulb could operate at 25 volts for 360 hours.

Wei predicted such bulbs could hit the market in three to five years, PhysicsWeb reported.

Light and length have been the subject of other nanotube research projects. In 2003, IBM and some university labs demonstrated that nanotubes could emit light. Researchers at Stanford, Duke and other universities have also come up with ways of creating relatively long nanotubes as well as aligning the tubes into larger structures.

#47 kevin

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Posted 09 June 2004 - 09:44 PM

Link: http://www.eurekaler...u-abs060904.php


Public release date: 9-Jun-2004
[ Print This Article | Close This Window ]

Contact: Richard Carter
r.j.carter@ncl.ac.uk
44-191-222-5477
University of Newcastle upon Tyne

Landmarks smaller than a pinhead

--------------------------------------------------------------------------------
Posted Image
Angel Blue
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Full size image available here.

Two major UK landmarks now count among the world's smallest objects.

Scientists & engineers based at the University of Newcastle upon Tyne specialising in miniaturisation technology have recreated North East England's Tyne Bridge and the Angel of the North sculpture so they are smaller than a pinhead and invisible to the naked eye.

The team used a combination of chemistry, physics and mechanical engineering techniques to create the tiny structures. Both are created out of silicon, the material used to make microchips. They are around 400 microns wide and their details can only be seen through a microscope.

The technology used to develop the bridge and the angel could be used to make miniaturised antennae for next-generation mobile phones. These so-called chip antennae will significantly reduce the power consumption and cost of production of mobile communication devices.

The fact that these structures can be made in silicon is an important feature as this allows the integration of moving mechanical parts and smart materials with standard components used in the microelectronics and semiconductor industries.


--------------------------------------------------------------------------------
Posted Image
--------------------------------------------------------------------------------
Gold Bridge
Full size image available here.

The scientists, who are based at INEX (Innovation in Nanotechnology Exploitation), the engineering & commercialisation arm of the Institute for Nanoscale Science & Technology at the University of Newcastle upon Tyne, undertook the project to showcase their expertise in an emerging technological field, micro electro mechanical systems (MEMS), in an interesting way.

The techniques are now being used by INEX to develop a number of applications on behalf of industry.

The applications range from accelerometer devices used in the automobile and medical markets; biosensors for rapid & cheap point-of-care diagnostics that are finding novel application in the healthcare sector; through to making grooves and channels 1/10th the width of a human hair to transfer picolitre (which is 0.0000000000001 litres) volumes of chemicals and biological materials for lab-on-a- chip applications that is enabling the generation of new and better drugs at a much faster pace than previously possible.

The business director of INEX, Richard Carter, said:

"Newcastle is already known for creating some of the UK's largest structures - and now the region is building a global reputation for making some of the smallest.

"These are not just gimmicks. The work was performed as part of a technology development programme looking at new ways to make very small structures and devices.

"The North East is a UK leader for this type of advanced technology and we are working hard to make sure that we remain on top of the market, which should ultimately boost the region's economy and create more jobs."


###
Images:
Pictures of the miniature structures can be downloaded from Newcastle University website. See the links below.

Angel of the North: http://www.ncl.ac.uk...66ANGELBLUE.jpg
Tyne-y Bridge: http://www.ncl.ac.uk...Bridge_Gold.jpg

About INEX: INEX is the business & commercialisation arm of the Institute for Nanoscale Science & Technology at the University of Newcastle. INEX operates some of the best public-sector micro- and nanofabrication facilities in the UK and runs projects on behalf of its industry clients. More about INEX can be found at the following website: http://www.inex.org.uk

Issued by Newcastle University Press Office
Email: press.office@ncl.ac.uk
Tel: 44-191-222-7850
Website (with searchable guide to expertise): http://www.ncl.ac.uk/press.office

Newcastle University has its own radio studio with ISDN line and is five minutes car journey from independent and BBC broadcasting studios.

#48 chubtoad

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Posted 18 June 2004 - 12:21 AM

http://www.eurekaler...t/chemistry.php

Gold-tipped nanocrystals developed by Hebrew University

"Nanodumbells" – gold-tipped nanocrystals which can be used as highly-efficient building blocks for devices in the emerging nanotechnology revolution – have been developed by researchers at the Hebrew University of Jerusalem.
The technology, developed by a research group headed by Prof. Uri Banin of the Department of Physical Chemistry and the Center for Nanoscience and Nanotechnology of the Hebrew University, is described in an article in the current issue of Science magazine.

The nanodumbells – shaped somewhat like mini-weightlifting bars – offer a solution to problems of building new, nanocrystal transistors, the basic component of computer chips.

Semiconductor nanocrystals are tiny particles with dimensions of merely a few nanometers. A nanometer (nm) is one-billionth of a meter, or about a hundred-thousandth of the diameter of a human hair. These nanocrystals exhibit unique optical and electrical properties that are controlled by modifying their particle size, composition and shape, creating promising building blocks for future nanotechnology devices, such as mini-computers, nanosensors for chemical and biological molecules, novel solar-cell devices, or for various biomedical applications.



#49 chubtoad

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Posted 30 June 2004 - 09:53 PM

http://www.eurekaler...mathematics.php

Physicists reveal first 'nanoflowers'

Today the Institute of Physics releases some of the most beautiful science images of the year so far, a collection of photomicrographs of tiny "flowers" and "trees" less than one thousandth the width of a human hair. The images are published in the Institute journal Nanotechnology.
These stunning images were taken by Ghim Wei Ho, a PhD student studying nanotechnology at Cambridge University. She has named some of her best photographs nanobouquet, nanotrees, and nanoflower because of their curious similarity to familiar organic structures such as flower-heads and tiny growing trees.

Ghim Wei's work involves making new types of materials based on nanotechnology and these flowers are an example of such a new material. Here, nanometre scale wires (about one thousandth the diameter of a human hair) of a silicon-carbon material (silicon carbide) are grown from tiny droplets of a liquid metal (Gallium) on a silicon surface, like the chips inside our home computers.

The wires grow as a gas containing methane flows over the surface. The gas reacts at the surface of the droplets and condenses to form the wires. By changing the temperature and pressure of the growth process the wires can be controllably fused together in a natural process to form a range of new structures including these flower-like materials.

Professor Mark Welland, head of Cambridge's Nanoscale Science Laboratory and Ghim Wei's supervisor, said:

"The unique structures shown in these images will have a range of exciting applications. Two that are currently being explored are their use as water repellant coatings and as a base for a new type of solar cell. We have already shown that as a coating water droplets roll off these surfaces when they are tilted at angles as small as 5 degrees. This behavior is a direct consequence of the ability of such nanostructured surfaces to strongly repel water".



#50 chubtoad

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Posted 01 July 2004 - 09:14 PM

http://www.nature.co.../040628-16.html

Nanowires get connected

Nickel vapour creates tiny transistor network.
1 July 2004
MARK PEPLOW

Molecule-sized switches regularly prompt headlines about a new generation of miniaturized electronic chips. But there's a catch.

Although researchers can shrink individual components of circuits to the nanoscale, they cannot wire them together without conventional connections, which are hundreds of times bigger than the components themselves.

It's akin to joining the latest Pentium chip to your computer with enormous crocodile clips and jump leads. "You lose most of the advantages you had in this very small structure," says Charles Lieber, a chemist from Harvard University, Massachusetts.

Now Lieber reckons he has the answer: a technique that could be used to create ready-wired nanocircuits that do not need cumbersome connections.



#51 chubtoad

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Posted 05 July 2004 - 09:52 PM

http://www.scienceda...40705082413.htm

Nanomaterial Yields Cool Results

A pinch of iron dramatically boosts the cooling performance of a material considered key to the development of magnetic refrigerators, report researchers at the National Institute of Standards and Technology (NIST) in the June 24 issue of the journal Nature. The achievement might move the promising technology closer to market, opening the way to substantial energy and cost savings for homes and businesses.

By adding a small amount of iron (about 1 percent by volume), the NIST team enhanced the effective cooling capacity of the so-called “giant magnetocaloric effect” material by 15 to 30 percent. The result, writes materials scientist Virgil Provenzano and his NIST colleagues, “is a much-improved magnetic refrigerant for near-room-temperature applications.”

The original material—a gadolinium-germanium-silicon alloy—already is considered an attractive candidate for a room-temperature magnetic refrigerant. However, its cooling potential is undercut by significant energy costs exacted during the on-and-off cycling of an applied magnetic field, the process that drives the refrigeration device. These costs—called hysteresis losses—translate into commensurate losses of energy available for cooling.

The iron supplement overcomes this disadvantage. It nearly eliminates hysteresis and the associated energy cost, permitting the material to perform near the peak of its potential.



#52 chubtoad

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Posted 15 July 2004 - 11:50 AM

http://www.ornl.gov/...r=mr20040714-00

ORNL nanoprobe creates world of new possibilities

OAK RIDGE, Tenn., July 14, 2004 — A technology with proven environmental, forensics and medical applications has received a shot in the arm because of an invention by researchers at the Department of Energy's Oak Ridge National Laboratory.
ORNL's nanoprobe, which is based on a light scattering technique, can detect and analyze chemicals, explosives, drugs and more at a theoretical single-molecule level. This capability makes it far more selective and accurate than conventional competing technologies.



#53 chubtoad

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Posted 16 July 2004 - 11:37 PM

http://www.anl.gov/O.../news040702.htm


Nanoparticles, super-absorbent gel clean radioactivity from porous structures

SUPERGEL – Argonne researchers are designing a system to safely capture and dispose of radioactive elements in porous structures outdoors, such as buildings and monuments, using this spray-on, super-absorbent gel and engineered nanoparticles. Such a system would help the nation be more prepared in the event of a terrorist attack with a “dirty bomb” or other radioactive dispersal device.

ARGONNE, Ill. (July 2, 2004) – Porous structures, such as brick and concrete, are notoriously hard to clean when contaminated with certain types of radioactive materials. Now, thanks to researchers in Argonne 's Chemical Engineering Division, a new technique is being developed that can effectively decontaminate these structures in the event of exposure to radioactive elements.

Researchers are using engineered nanoparticles and a super-absorbent gel to design a clean-up system for buildings and monuments exposed to radioactive materials. Having this system available will allow the nation to be more prepared in case of a terrorist attack with a “dirty bomb” or other radioactive dispersal device.

“If a radioactive device were activated in public, the primary concern would be widespread contamination,” said Michael Kaminski, lead scientist of the project. “This contamination is particularly hard to remove in buildings made from brick or concrete, where the pores, or holes, in those materials make it easy for radioactive materials to become trapped.”

Enter Kaminski and his team of Argonne scientists, whose decontamination system could safely capture and dispose of radioactive elements in porous structures in an outdoor environment. Using a simple, three-step procedure, the system operates much like an automated car wash, where remote spray washers apply a wetting agent and a super-absorbent gel onto the contaminated surface. The wetting agent causes the bound radioactivity to resuspend in the pores. The super-absorbent polymer gel then draws the radioactivity out of the pores, and fixes it in the engineered nanoparticles that sit in the gel. Finally, the gel is vacuumed and recycled, leaving only a small amount of radioactive waste.



#54 Lazarus Long

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Posted 16 August 2004 - 01:10 AM

This approach appears to be bearing fruit both for nanotech and for possible proteomic applications.

http://story.news.ya...notechnology_dc

Genetic Material May Help Make Nano-Devices: Study

Thu Aug 12,10:18 AM ET  Add Science - Reuters to My Yahoo!

WASHINGTON (Reuters) - The genetic building blocks that form the basis for life may also be used to build the tiny machines of nanotechnology, U.S. researchers said on Thursday.

A team at Purdue University said they had used ribonucleic acid, or RNA, to build microscopic structures such as spirals, triangles, rods and hairpins, that could serve as components of nanotechnology devices.

Nanotechnology is the science of making devices on the scale of nanometers -- billionths of a meter. Such "nanoscale" devices might be used in medicine, or as computers woven into everyday materials such as clothing.

"Biology builds beautiful nanoscale structures, and we'd like to borrow some of them for nanotechnology," Peixuan Guo, a professor of molecular virology at Purdue, said in a statement.

The work of Guo and colleagues at Purdue's School of Veterinary Medicine was reported in the August issue of the journal Nano Letters.

RNA is the information carrier for genetic material. While DNA contains the instructions for producing proteins, RNA molecules carry the instructions into the cell's machinery.

In their experiment, Guo and his colleagues tried to exploit RNA's ability to assemble itself into shapes.

So far researchers have faced problems trying to manipulate the miniature components needed for nanotechnology, Guo said. "We are short of tiny steam shovels to push them (the components) around. So we need to design and construct materials that can assemble themselves."

Dieter Moll, a researcher in Guo's lab, said the components made with RNA could be useful to industrial and medical specialists, who would appreciate "their ease of engineering and handling."

"Self-assembly means cost-effective," he said.


http://www.msnbc.msn.com/id/5684791/

BioBots
http://www.sciencent...anguage=english

RNA Could Form Building Blocks for Nanomachines
http://www.ascribe.o...r=2004&public=1

Peixuan Guo
http://www.vet.purdue.edu/PeixuanGuo/

#55 lightowl

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Posted 16 August 2004 - 01:14 AM

Here is CRN's take on the RNA thing.

http://crnano.typepa...hnology__1.html

And another article.

http://www.physorg.com/news790.html

#56 Lazarus Long

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Posted 25 October 2004 - 06:26 PM

Alright, today's NY Times has a great article worth reading and keeping so here it is and the future is in biomimetics, from VR dildonics to personal flying machines. From augmented bodies for deep sea habitat to asteroid mining.

Posted Image
Tiny Ideas Coming of Age
By BARNABY J. FEDER
Published: October 24, 2004

Posted Image
Plastics that flex and contract like muscles when an electrical current is applied are among the new materials being created in nanotechnology labs.

YOU cannot, strictly speaking, baptize a technology, for it has no soul. But you could say that something like that rite of passage occurred last Monday, when the United States Patent and Trademark Office announced a new registration category just for nanotechnology inventions.

Nanotechnology is the realm of the very, very small: its name comes from the nanometer, a unit of measure so tiny that a human hair is roughly 80,000 nanometers thick. Individual molecules are measured in nanometers; so are viruses, strands of DNA, and the microscopic structures that determine the performance of everyday materials like steel and plastic.

The patent office's definition requires that a least one dimension of an invention be less than 100 nanometers, but smallness alone is not enough. The nanoscale element of the product or process must be essential to whatever properties make it novel.

"People looking for venture capital money will call anything small 'nanotechnology,' " said Bruce Kisliuk, director of the section of the patent office that handles biotechnology and pharmaceutical applications, who is coordinating the work on nanotechnology issues.

The decision to set up Class 977, as the new category will be formally called, is a recognition that a swarm of nanoscale inventions is headed the patent office's way. Some are already on the market, including fibers for clothing and mattresses that are highly stain resistant and water resistant; particles of titanium dioxide that make sunscreen transparent; and nanocrystals of silver for antimicrobial bandages.

These products are the vanguard of a technology that is expected to touch every part of the economy, the way computers have. But there is an important difference, according to Lux Research, a technology research company in New York. Information technology was about recording and analyzing the physical world, but nanotechnology is about changing how the physical world behaves. For example, a hospital computer may keep track of when a patient will receive a hip-implant operation, how his blood tests came back and who his insurer is, but a nanoscale coating on the surface of his implant affects how it performs in his body.

Depending on how you define it, nanotechnology may already be contributing billions of dollars to the economy. The National Science Foundation predicted in 2001 that nanotechnology would contribute $1 trillion by 2015, and some experts, including the people at Lux, think that figure might be low.

The nanotechnology surge is confronting the patent office with a familiar problem - assessing claims of innovation that do not match up neatly with the way patent examiners are trained to categorize them - but on a whole new scale. The danger is that an examiner trained in, say, chemistry will be running into nanotechnology patent claims that also touch on physics and biology, and may overlook previous inventions or publications in those fields that are relevant to whether a new claim is patentable.

The patent office began training its examiners in nanotechnology concepts and terminology in November, and has set up a working group of outside lawyers and researchers to give advice. But that has not been enough to head off confusion in a realm where the same invention might be called a carbon nanotube, an elongated cylinder made of carbon or a carbonaceous cylinder in three separate patent applications, according to experts like Stephen B. Maebius, an intellectual property lawyer in Washington and former patent examiner.

As a result, Mr. Maebius and other lawyers say, a number of overlapping patents have already been issued. The potential for years of legal battles could freeze development in its tracks, according to Matthew Nordan, vice president of research at Lux.

"It's the biggest threat to commercialization," Mr. Nordan said.

#57 Mind

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Posted 12 December 2004 - 04:12 PM

Nanotubes glow, even within biological cells

Nanotubes glow, even within biological cells
Scientists use fluorescence to track ultrafine particles taken up by white blood cells
HOUSTON, Dec. 8, 2004 -- In some of the first work documenting the uptake of carbon nanotubes by living cells, a team of chemists and life scientists from Rice University, the University of Texas Health Science Center at Houston and the Texas Heart Institute have selectively detected low concentrations of nanotubes in laboratory cell cultures.

The research appears in the Dec. 8 issue of the Journal of the American Chemical Society. It suggests that the white blood cells, which were incubated in dilute solutions of nanotubes, treated the nanotubes as they would other extracellular particles – actively ingesting them and sealing them off inside chambers known as phagosomes.

"Our goal in doing the experiment was both to learn how the biological function of the cells was affected by the nanotubes and to see if the fluorescent properties of the nanotubes would change inside a living cell," said lead researcher Bruce Weisman, professor of chemistry at Rice. "On the first point, we found no adverse effects on the cells, and on the second, we found that the nanotubes retained their unique optical properties, which allowed us to use a specialized microscope tuned to the near-infrared to pinpoint their locations within the cells."

The research builds upon Weisman's groundbreaking 2002 discovery that each of the dozens of varieties of semiconducting, single-walled carbon nanotubes (SWNTs) emits its own unique fluorescent signature.

The new findings suggest that SWNTs might be valuable biological imaging agents, in part because SWNTs fluoresce in the near-infrared portion of the spectrum, at wavelengths not normally emitted by biological tissues. This may allow light from even a handful of nanotubes to be selectively detected from within the body.

Carbon nanotubes are cylinders of carbon atoms that measure about one nanometer, or one-billionth of a meter, in diameter. They are larger than a molecule of water, but are about 10,000 times smaller than a white blood cell.

The latest tests bode well on two counts. Not only did the nanotubes retain their optical signatures after entering the white blood cells, but the introduction of nanotubes caused no measurable change in cell properties like shape, rate of growth or the ability to adhere to surfaces.



#58 chubtoad

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Posted 15 December 2004 - 05:06 AM

http://www.nature.co...l/041213-2.html

Living cells get nanosurgery
Mark Peplow
Tiny needle can operate on a single cell without leaving damage. 
Human liver cells remained healthy after an hour of nanosurgery.

A tiny needle that can perform keyhole surgery on a single living cell could aid biologists researching gene therapy and developing new drugs.

Using microscopic lances to remove material from fertilized eggs is now a routine technique. But these microcapillaries are still quite clumsy and difficult to control precisely without damaging the cell. As they press through the cell wall, it is often deformed so badly that the cell dies.

Now, Japanese researchers have turned an atomic force microscope (AFM) into a surgical tool for cells that could add or remove molecules from precise locations inside a cell without harming it.



#59 chubtoad

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Posted 31 May 2005 - 02:24 AM

TechnologyReview some recent and projected charts on nanotech funding and public knowledge. http://www.techrevie...ue/datamine.asp




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