Recently in Nanoscale science and technology Category

Science: Nanotechnology research requires more oversight regarding human and environmental safety, says a new report from the US National Research Council (NRC). Although the National Nanotechnology Initiative (NNI) studies the safety of nanomaterials, the NRC has found gaps in its guidelines. For example, little research has been done on the effects of human ingestion of nanoparticles or on the safety of complex nanomaterials made up of mixtures of different elements.

Potentially the most disruptive recommendation in the report is to change who oversees nanotechnology risk research. NNI currently consists of 25 different federal agencies that work with the National Nanotechnology Coordination Office to coordinate their research efforts to avoid duplication. But neither the NNI nor the Coordination Office have any authority to mandate who does what. The NRC suggested several possible solutions, including setting up a panel with budgetary authority within the White House's Office of Science and Technology Policy.

Daily Mail: Researchers at the University of Texas at Austin have succeeded in cloaking a three-dimensional object. According to their results published today in the New Journal of Physics, the group used plasmonic metamaterials to hide an 18-cm cylindrical tube illuminated by microwave radiation. Plasmonic metamaterials scatter light rays differently from the way more common materials do. "When the scattered fields from the cloak and the object interfere, they cancel each other out and the overall effect is transparency and invisibility at all angles of observation," said Andrea Alù, one of the study’s coauthors. One of the next challenges will be to demonstrate cloaking in visible light.

BBC: Researchers at Duke University have been working to develop synthetic nanoparticles that can boost the human body's immune system. They have engineered tiny capsules that mimic mast cells—which respond to fight infections near the skin—by releasing a body chemical called tumor necrosis factor, which battles certain types of bacteria and viruses. The nanoparticles, when injected into mice simultaneously with a vaccine, have been shown to improve the infected animals’ survival rate. Soman Abraham and colleagues said different immune system chemicals could be added to the nanoparticles, depending on which vaccine will be used.

New York Times: The chrome look is making a comeback for automobiles, writes Tudor Van Hampton for the New York Times. However, rather than actual chrome, which is expensive and heavy, manufacturers are using materials that mimic chrome. One such material has been produced by Hamlin Jennings, a cement scientist at MIT who has developed a process to coat aluminum with a thin layer of glass. The glass chemically fuses to the metal, producing the look of polished chrome and protecting the surface from scratches and oxidation. The process will probably be used mainly in luxury vehicles for trim around windows and headlights. For most purposes, a good-quality shiny plastic is just as effective and much less expensive.

Nature: New research indicates that not everything on a quantum level exhibits quantum behavior. Wires just a few nanometers wide have now been shown to conduct electricity in the same way as the larger components of existing devices. Michelle Simmons, a physicist and director of the Centre for Quantum Computation and Communication Technology at the University of New South Wales in Sydney, Australia, and her colleagues made atomic-scale wires of phosphorous-doped silicon in which the phosphorous provided the extra electrons needed to generate a current, writes Edwin Cartlidge for Nature. Although the width of the wires varied from 1.5 to 11 nm, the resistivity did not differ substantially, thus obeying Ohm’s law of classical electronics. David Ferry, an electrical engineer at Arizona State University in Tempe, noted the importance of the finding to such devices as transistors, which every two years have been shrinking in size yet yielding ever-better performance—a trend known as Moore’s law. If quantum coherence came into play, he said, the transistors wouldn’t turn on and off as expected. Therefore, the new research could have significant implications for the microchip industry. What the implications will be for quantum computing, however, remains to be seen.

ScienceDaily: Researchers at Purdue University have designed V-shaped gold and silicon nanoantennas that can cause broadband light to bend in unusual ways, including with negative angles of refraction. Extending earlier work by a group at Harvard University, the Purdue team showed that an array of the nanoantennas at a material interface can change the phase and propagation direction of light over a broad range in the near-IR. The arrays, much thinner than the light’s wavelengths, produced dramatic deviations from the conventional laws governing how light refracts as it passes from one material to the next. Says team member Vladimir Shalaev, "Not only the bending effect, refraction, but also the reflection of light can be dramatically modified by the antenna arrays on the interface, as the experiments showed." Shalaev is the scientific director of nanophotonics at Purdue's Birck Nanotechnology Center and one of the authors of a paper published online yesterday in Science. The team’s technique could have a range of technological applications, including in fiber-optic telecommunications and in more powerful microscope lenses.

Science: Researchers at the US National Renewable Energy Laboratory (NREL) have created a new type of solar cell that captures some of the excess solar energy normally lost as heat, writes Robert Service for Science. When high-energy photons from the Sun hit a semiconducting material in a solar cell, they excite the semiconductor’s electrons from a static position so they can conduct. But the photons carry more energy than is needed, and the rest gets lost as heat. Several years ago, it was found that the high-energy photons can excite more than one electron if the semiconductor consists of nanometer-sized particles called quantum dots. The NREL group used the process, known as multiple exciton generation (MEG), in their quantum dot solar cell to achieve a 5% overall efficiency at converting light to electricity. That efficiency is still well below conventional silicon solar cells, which make better use of the full solar spectrum. But the device is the first to collect more electrical charges than the number of photons that struck the quantum dots—a convincing demonstration of MEG. The group’s results were published 16 December.

BBC: Clemens Bechinger of the Max Planck Institute for Intelligent Systems at the University of Stuttgart and his colleagues have built a tiny steam engine based on the Stirling engine invented in 1816. Bechinger and his team wanted to know if the engine's basic operating principle would work at the microscale. To adapt the engine to that size, they replaced the original design's cylinder of gas with a micron-sized particle of melamine submerged in a tiny chamber of water. A focused IR laser beam took the place of pistons and acted as optical tweezers to hold the melamine in place. A second laser was used to heat the water, which cooled back to room temperature as soon as the laser was turned off. The micro-engine was as efficient, but not as stable, in its energy production as a full-sized Stirling engine. Water molecules in the solution surrounding the melamine constantly collided with the microparticle, causing energy to be passed back and forth. In a larger engine the amount of energy generated makes such collisions irrelevant, but in the microscopic engine the energy levels are too similar. While the micro-engine isn't a practical power source, the team's research could be used to create more stable power sources for micromachines.

BBC: A group of researchers at the University of Washington in Seattle is developing a contact lens that can project images in front of the eye through the use of an embedded pixel array. Such a device has been challenging to create because it not only requires a suitable power source and mechanical and electrical integration of its micrometer-scale components but it also must be biocompatible. In addition, the human eye usually can focus only on objects at least a few centimeters away, whereas a contact lens rests on the eye’s surface. Nevertheless, the researchers have built a single-pixel prototype device, which they have successfully tested on rabbits. In humans, such lenses could have many uses, such as to relay information from navigation systems, enhance video gaming, or alert the wearer to physiological problems like abnormal glucose levels, write Babak Parviz and colleagues in the Journal of Micromechanics and Microengineering.

Talking Points Memo: Researchers at HRL Laboratories, Caltech, and the University of California, Irvine have created the world’s lightest material—ultralight metallic microlattice. The researchers poured a liquid material into the microlattice pattern and hardened it by exposing it to UV light, writes Carl Franzen for Talking Points Memo. Electroless nickel—an alloy of nickel and phosphorous—was then poured onto the pattern very precisely, forming a 100-nanometer-thin uniform coating. The resulting material is 99.99% air and has a density of only 0.9 mg/cc. Much lighter than Styrofoam, it floats to the ground like a feather when dropped, according to William Carter of HRL, one of the authors of a recent Science paper on the subject. However, it is the structure itself that is important, not the material it is made from. According to Carter, his team can “make the same structure out of many different materials,” including polymers and ceramics. Developed for the Defense Advanced Research Projects Agency, such ultralight cellular materials could be used in thermal insulation, batteries, and acoustics.

IEEE Spectrum: Engineers at Yale University have developed a nanomechanical resonator, a new type of mechanical memory device that uses lasers to record and read information. A tiny piece of silicon is bent up or down by the light propagating inside a photonic circuit, writes Neil Savage for IEEE Spectrum. Once the light is switched off, the piece remains in one of those states, which represents the 1s and 0s of digital coding. Because the two states are separated by a huge energy barrier, they stay put when the laser is turned off. To read the memory, the researchers use a lower-energy laser to avoid flipping the bits. Hong Tang and coworkers, whose results were published 23 October in Nature Nanotechnology, say the device could lead to better sensors and new techniques in optical telecommunications.

ABC News: Researchers at the University of Texas at Dallas have succeeded in creating a working cloaking device; they published the details this week in the journal Nanotechnology. For their device Ali Aliev and colleagues made a porous sponge out of sheets of carbon nanotubes, which are known for their exceptional ability to conduct heat and transfer it to surrounding areas. When a steep temperature gradient is imposed on the sponge, the refractive index of the surrounding air also acquires a steep gradient. Light rays are bent away from an object, just as in a desert mirage, and make the object seem invisible. The researchers have posted a video of their device in action in the lab.

Daily Mail: Researchers at Tufts University in Massachusetts have built the world’s smallest electric motor—consisting of a single molecule just a nanometer in size, or 1/60 000 the diameter of a human hair. Using a scanning tunneling microscope, Charles Sykes and coworkers rotated a single butyl methyl sulfide molecule by nudging it with an electric field. Although molecular motors powered by other means, such as chemical reactions or light, have been built, they cannot achieve the precision of the Tufts team's electric motor: Even the smallest amount of chemicals or the narrowest beam of light will affect clusters of molecules. The team’s electric motor, as detailed in Nature Nanotechnology, could lead to advances in medicine, to deliver tiny amounts of drugs to very specific locations, and in nanosensors.

Science: Physicists at the University of Innsbruck, Austria, have turned a single atom into a mirror. Gabriel Hétet, Rainer Blatt, and colleagues set up a Fabry–Pérot interferometer, replacing one of the device’s two mirrors with a barium ion. Using an electronic trap to hold the ion in place and a lens to focus the laser light, they tuned the wavelength of the light entering the interferometer so that it could excite the atom from a particular low-energy state to a higher-energy one. Without such a light–atom interaction, the atom can't affect the light, writes Adrian Cho for Science. Although the interferometer wasn’t perfect—as the researchers moved the ion away from the mirror, the amount of light coming through the system varied by about 6%—the atom still managed to work as a mirror. Such work in quantum electrodynamics could lead to ever smaller optical devices, such as an atom-sized transistor for light. The team reports its results in a paper to be published in Physical Review Letters.

Chronicle of Higher Education: University campuses across Mexico are on alert after two professors were injured by a package bomb at the Monterrey Institute of Technology and Higher Education earlier this August. Both men are expected to recover. The incident was the latest in a series of attacks by a terror group (or a single person posing as such) that calls itself "Individualities Tending Toward Savagery" and credits Theodore Kaczynski, also known as the Unabomber, as an inspiration. The group's rhetorical style may indicate affiliation with a college, according to one analyst, who also helped identify the Unabomber. In an online statement claiming credit for the Monterrey Institute bombing, the group cites fears that the rapid acceleration of nanotechnology will lead to the development of self-replicating nanomachines. The University of the Americas, Puebla, the first Mexican institution to offer an undergraduate nanotechnology major, has sent an email message to all students, professors, and staff, warning them not to open suspicious packages. And Mexican law enforcement has called on universities across the country to strengthen their security.

Daily Mail: Researchers at the UK’s University of Southampton have developed millimeter-sized memory devices made of glass. The team, led by Peter Kazansky at the university’s Optoelectronics Research Center, used ultrashort laser pulses to imprint tiny dots called voxels (like three-dimensional pixels) in pure silica glass. The voxels can then be read using an optical decoder, and users can write or delete data as often as they like. The crystals can store more than conventional hard drives, are less prone to overheating or damage, and can last indefinitely. Since publication of their work in May in Applied Physics Letters, the researchers have developed the technology further and adapted it for a five-dimensional optical recording.

New Scientist: In a study published in Nature Materials, two physicists at Argonne National Laboratory, Alexey Snezhko and Igor Aronson, describe the creation of tiny robots, just half a millimeter wide, from microparticles suspended between two layers of immiscible fluids. When they apply a magnetic field perpendicular to the liquid surface, the particles self-assemble into star shapes, or asters. Applying a second magnetic field parallel to the surface causes the asters to swim. By changing the magnetic field, the researchers can remotely control the asters’ motion. "We can make them open their jaws and close them," said Snezhko in a press release. "This gives us the opportunity to use these creatures as mini-robots performing useful tasks. You can move them around and pick up and drop objects." The asters have several advantages over other micromanipulators: They can handle items more delicately than their mechanical counterparts, and they are self-repairing—if particles are lost, the remaining particles simply reshuffle themselves.

New Scientist: Can large objects follow quantum laws? To answer that question, Oriol Romero-Isart from the Max Planck Institute of Quantum Optics in Garching, Germany, and colleagues are experimenting to see whether a nanometer-sized glass sphere can exist in two entirely distinct places at one time, with no overlap. They propose placing the sphere in a small cavity and striking it with a laser, causing it to bounce around in the cavity. But since the light is quantum in nature, writes Michael Brooks for New Scientist, so too will be the position of the sphere, which forces the sphere into a quantum superposition. So far, such superposition has only been achieved with molecules containing a few hundred atoms. Romero-Isart is lead author on the group’s paper published 8 July in Physical Review Letters.

Nature: Sangeeta Bhatia of MIT and colleagues have designed two different types of cancer-fighting nanoparticles to work in tandem and piggyback on the body's rapid response to clotting, writes Nature's Corie Lok. Bhatia's team created a scout particle to fit through the abnormally large pores in a tumor's blood vessels; when near-IR light is shone on the scout particles, they heat up just enough to damage the tumor and trigger a rapidly escalating molecular response known as the clotting cascade. The drug-bearing nanoparticle has a protein on its surface that is a substrate for an enzyme called factor XIII, which crosslinks fibrin at the end of the cascade; the particles are attracted as the clotting process occurs. Factor XIII crosslinks the nanoparticles' protein to the fibrin in the clot, and the particles then deliver the drug. The factor XIII and fibrin generated during the clotting process create additional binding sites for the particles; that process leads to a 40-fold increase in the amount of drug delivered compared with drug-delivering nanoparticles already in use.

Science News: Scientists have spun a multitude of high-tech materials into bundles of superfine nanowires that are more than 1000 meters long, writes Rachel Ehrenberg for Science News. Although trimming big, bulky materials down to nanosize has proven difficult in the past, Mehmet Bayindir of the Institute of Materials Science and Nanotechnology at Bilkent University in Turkey and colleagues have succeeded in doing so with a solid rod of material wrapped in polymer. They heated the rod, drew it out in a long micrometers-thick thread, cut that into 15-cm lengths, consolidated the lengths into a bundle, and heated and spun that into even finer thread. Not only are the wires they produced exceedingly long, they are also homogeneous. The new technique, reported online in Nature Materials, produces uniform, orderly arrays of gossamer-thin materials that could have broad use in sensors, energy-harvesting devices, and medical diagnostics.

Washington Post: Federal agencies announced Thursday that they will seek to clarify the role nanomaterials can have in consumer items such as cosmetics and food production, writes Darryl Fears for the Washington Post. The Environmental Protection Agency will investigate whether nanomaterials in pesticides can have adverse effects on human health and the environment; the agency will publish its policy proposal, a draft of which is available here, in the Federal Register and make it available for public comment during the week of June 13 at www.regulations.gov in docket number EPA-HQ-OPP-2010-0197. The Food and Drug Administration released draft guidelines to regulated industries about whether regulated products involve nanotechnology; they have made the document available online for public comment.

New York Times: Yesterday Intel announced that it was going three-dimensional in its computer-chip manufacturing. John Markoff for the New York Times writes that Intel has begun making its microprocessors using a new 3D transistor design, called a Finfet (fin field-effect transistor). Intel predicts that the new design—which includes a small pillar, or fin, of silicon that rises above the surface of the chip—will allow the chips to run 37% faster in low-voltage applications, cut power consumption as much as 50%, and make the chip even smaller. While the smallest feature on one of Intel's chips is just 32 nanometers (a human red blood cell is 7500 nanometers wide), "Intel is on track for 22-nanometer manufacturing later this year," said Mark Bohr, an Intel senior fellow. The 3D transistor is seen by some as a gamble, however, because despite its speed, it will not be as ultralow-powered as some chips and therefore not as ideal for smaller devices, such as iPhones and iPads.

Science: Traditional microscopes can't resolve objects smaller than half the wavelength of the light used to illuminate them; electron microscopes get around this by replacing the visible light with electron beams, which have a much shorter wavelength and a much smaller intrinsic blur. However, electrons pass right through thin samples of most living tissue unless it's been prepared in a radical way—which prevents researchers from viewing living organisms. E. G. van Putten, of MESA+ Institute for Nanotechnology in Twente, the Netherlands, and colleagues etched a gallium phosphide lens with sulfuric acid to produce a frosted surface that scattered light in all directions. They then used a computer to design a light wave that, when passed through and scattered by the lens, would focus to a point. It seems counterintuitive, but the randomization and reconstruction process allowed the researchers to form a sharper image than would otherwise have been possible. They were also able to create an ultrasharp image of the entire sample by rotating the incoming light wave and scanning the focus across the sample. Thus far, they have imaged gold nanoparticles with a resolution as small as 97 nm. With a more powerful light source and some fine-tuning, it should be possible to see details of living tissue samples, including nanoscale processes such as viruses invading cells.

New Scientist: Amy Prieto and colleagues at Colorado State University in Fort Collins are developing a rechargeable battery that is smaller, lighter, and more rapidly rechargeable than current electric car batteries. According to Helen Knight, writing for New Scientist, the battery has hairbrush-like electrodes that can be charged in just a few minutes. Instead of the current design used in lithium-ion batteries, which consist of a graphite anode and lithium cathode with an electrolyte sandwiched between them, Prieto's battery uses nanowire anodes made of copper antimonide. The large surface area of the millions of nanowires means they can store twice as many lithium ions as the same amount of graphite. Prieto, who has founded the company Prieto Battery, discussed the team's prototype battery at the American Chemical Society meeting this week in Anaheim, California.

NPR: Nanodiamonds—clusters of a few hundred carbon atoms—may find a use in the treatment of cancer. Researchers at Northwestern University infected lab mice with chemo-resistant breast and liver cancers and then tested two treatments. Mice that were injected with nanodiamonds covered in the drug doxorubicin fared better than those given unbound doxorubicin. Nanodiamond-bound doxorubicin tends to stick around in mice up to 10 times longer than unbound doxorubicin does, leading to a slower, more sustained therapy. The high retention of the nanodiamonds within tumors means that smaller, less harmful doses can be used. As nanodiamonds are already in use in the automotive industry as a lubricant, they are mass-produced and don’t cost much. The results of their work appear in the latest issue of Science Translational Medicine.

New York Times: Gains in computer power have come from making circuits smaller. But as the wires, transistors, and other circuit components shrink, their electrical resistance—and therefore their power consumption and heat output—rises. The most powerful supercomputers already consume as much power as a small town. To curb that growth, researchers at Hewlett-Packard have proposed a radical reconfiguration of a computer's two basic elements: processor and memory. As the New York Times's John Markoff reports, HP's new configuration mitigates the energy cost of shuttling information between the processor and memory by placing the two elements on top of each other. Another innovation is the use of nanotech devices known as a memristors to serve as memory stores.

New Scientist: The elusive goal of integrating lasers and electronics has come a big step closer with the first growth of nanoscale lasers directly on silicon. Silicon itself is a poor laser material. The tiny lasers are made instead from indium-gallium-arsenide, which is usually hard to grow directly on silicon. In a paper published in Nature Photonics, Connie Chang-Hasnain of the University of California, Berkeley, and her colleagues describe a novel growth scheme that overcomes the integration roadblock.

New Scientist: Nanotechnologists have developed conducting fabrics that can survive a washing machine, reports Paul Marks for New Scientist. Researchers at the University of Texas at Dallas, who have published their results in Science, have been experimenting with nanotube yarns peppered with “guest” particles wrapped up in a tightly scrolled web. Besides use in clothing, the technique could have other engineering applications, such as in batteries and supercapacitors.

New Scientist: Argento Diagnostics, a company spun off from the UK's National Physical Laboratory, has used nanotechnology and microfluidics to tackle a problem in the training of elite athletes: How do you monitor the levels of key metabolic molecules without having to send samples to a lab? Argento's solution is a handheld device that can take a sample of an athlete's blood, saliva, or urine and send it through microfluidic channels, where it mixes with silver nanoparticles and larger magnetic nanoparticles, both of which are coated with antibodies. In the presence of a biomolecule of interest, the silver nanoparticles stick to the magnetic nanoparticles. Flushing off the silver nanoparticles creates a concentration of silver ions whose charge is proportional to the amount of biomolecule in the sample.

Ecoseed: Scientists at the University of Missouri used cinnamon to replace almost all the toxic chemicals needed for making gold nanoparticles. They mixed gold salts with cinnamon and stirred the mixture in water. Kattesh Katti, professor of radiology and physics in the School of Medicine and the College of Arts and Science, said the process is environmentally friendly because it uses no electricity and utilizes no other toxic chemicals. Gold nanoparticles are used in electronics and healthcare. Katti uses his for cancer treatment, which was the focus of his study published in Pharmaceutical Research.

Washington Post: This year's physics Nobel went to Andre Geim and Konstantin Novoselov for discovering in 2004 how to make graphene, a two-dimensional form of carbon. The discovery excited physicists and engineers because of graphene's superb electrical and mechanical properties. Writing in the Washington Post, Brian Palmer examines when those properties will prove profitable. The main source of delay lies in finding a way to make the material cheaply and in large batches. Palmer concludes:

As chic as graphene is today, it's still really a material of the future. But there's so much money and excitement in graphene research, the future may be soon.

Daily Mail: Recent advances in nanotechnology could turn Willy Wonka’s Three-Course Dinner Chewing Gum into reality. In Roald Dahl’s 1964 novel Charlie and the Chocolate Factory, the gum first tastes like tomato soup, then roast beef and baked potato, and finally blueberry pie and ice cream. Now, food scientist Dave Hart and coworkers at the UK’s Institute of Food Research (IFR) say they have cracked the secret behind creating such a stick of chewing gum. Hart and his team are experimenting with creating different flavor layers separated by a tasteless gelatin, with a final dessert taste at the center, encapsulated in a high-tech gel called Gellan. “Tiny nanostructures within the gum would contain each of the different flavors. These would be broken up and released upon contact with saliva or after a certain amount of chewing,” says Hart.

Daily Mail: Researchers at the University of California, Berkeley, have developed a touch-sensitive artificial "skin"—dubbed "e-skin"—made of thin flexible material embedded with inorganic semiconductor nanowires. According to Ali Javey, head of the Berkeley research team, ''The idea is to have a material that functions like the human skin, which means incorporating the ability to feel and touch objects." The material could be used on robots and perhaps even on humans with artificial limbs, which would require more sophisticated techniques involving integration of electronic sensors with the human nervous system. The group has published its findings in Nature Materials.

Nature: Harvard University’s Charles Lieber and his colleagues have developed an electrical probe that’s so tiny it can be inserted into a cell’s membrane without disrupting it. To make the probe, Lieber’s team took a silicon nanowire, bent it into a hairpin, coated it with lipids (the same type of molecules make up the membrane), and attached it to a tiny field-effect transistor. A paper describing the probe’s fabrication, operation, and performance appears in today’s issue of Science.

Be aware that, as you align your research questions more closely to policy issues, you're also exposing yourself publicly. As the public debate about climate change reminds us, it can get nasty, so you'd better be prepared.

New York Times: It’s long been appreciated that the vivid colors of butterfly wings arise not from pigments, which selectively absorb certain frequencies, but from intrinsic microstructures, which selectively refract certain frequencies. Now, Yale University’s Richard Prum and his collaborators have figured out how those microstructures grow as the butterfly develops inside its chrysalis.

New Scientist: To get complicated nanostructures on a silicon chip it is sometimes necessary to grow them in separate layers and then transfer these one by one onto the final chip (PDF) to build them into working components.

Often it takes strong chemicals to separate the layers from the surface on which they are grown, and high temperatures may be needed to activate the thermal adhesives that keep the components in place at their destination.

Grégory Schneider and Cees Dekker at the Kavli Institute of Nanoscience in Delft, the Netherlands, have found a way to use water to quickly and easily transfer layers from one surface to another. They exploit the fact that different materials have different hydrophilicity—the tendency to attract water through transient hydrogen bonds.

Various: Hewlett-Packard scientists last week announced a new advancement in memristors or memory resistors. They were theoretically conceived in 1971 by Leon O. Chua, an electrical engineer at the University of California, Berkeley, but they were not put into practical effect until 2008 at an HP lab.

Memristors are simpler than today’s semiconducting transistors, but can store information even in the absence of an electrical current.

The new breakthrough, published in Nature, is that a memristor can perform logic steps, potentially enabling computation to be performed in chips where data are stored.

Related news pick
Big advance reported in memory chip design

Related links
From lab to fab—An HP Labs discovery demonstrates the viability—and versatility—of memristor technology HP press release
‘Memristive’ switches enable ‘stateful’ logic operations via material implication Nature
HP labs outlines breakthroughs in memristor chip research eWeek
HP sees a revolution in memory chip New York Times

Nature: Gold nanoparticles coated with a thin layer of an oxide allow molecules adsorbed on surfaces of materials as diverse as platinum, yeast cells, or citrus fruits to be characterized routinely in the laboratory through the use of spectroscopy.

Related link
Shell-isolated nanoparticle-enhanced Raman spectroscopy

Nature News: If quantum computing networks are ever to become a reality, physicists must find a way to direct and harness the light emitted in quantum experiments without using cumbersome apparatus.

Now Holger Hofmann, at the Department of Quantum Matter at Hiroshima University in Japan, and his colleagues have developed a way to control the direction of light on the nanoscale. Their technique is based on the workings of the Yagi-Uda antenna commonly used to transmit and detect shortwave radio waves.

Science: The different colors on the surface of a soap bubble arise from the interference of light waves reflecting from the outer and inner surface of the liquid film. As the thickness of the film varies, so will the wavelength of light that undergoes constructive interference and remains visible.

According to quantum mechanics, even material particles such as electrons behave like waves. In addition to their charge, electrons also have two distinguishable spin states, spin-up and spin-down.

In Science, Petta and associates demonstrate beam splitting and interferometry for the spin degrees of freedom of two electrons on a semiconductor chip.

Related link
A coherent beam splitter for electronic spin states

Physics Today: IBM researchers demonstrated a radio-frequency graphene transistor with the highest cut-off frequency achieved so far for any graphene device—100 billion cycles/second (100 gigahertz).

The high frequency record was achieved using wafer-scale, epitaxially grown graphene using processing technology compatible to that used in advanced silicon device fabrication.

"A key advantage of graphene lies in the very high speeds in which electrons propagate, which is essential for achieving high-speed, high-performance next generation transistors," said T. C. Chen, vice president of science and technology, IBM Research. "The breakthrough we are announcing demonstrates clearly that graphene can be utilized to produce high performance devices and integrated circuits."

Graphene is a single atom-thick layer of carbon atoms bonded in a hexagonal honeycomb-like arrangement. This two-dimensional form of carbon has unique electrical, optical, mechanical, and thermal properties, and its technological applications are being explored intensely.

Uniform and high-quality graphene wafers were synthesized by thermal decomposition of a silicon carbide (SiC) substrate.  The graphene transistor itself utilized a metal top-gate architecture and a novel gate insulator stack involving a polymer and a high dielectric constant oxide. The gate length was modest, 240 nanometers, leaving plenty of space for further optimization of its performance by scaling down the gate length.

The frequency performance of the graphene device already exceeds the cut-off frequency of state-of-the-art silicon transistors of the same gate length (~ 40 GHz).  

WSJ.com: Adam Keiper, editor of the New Atlantis and a fellow at the Ethics and Public Policy Center, expresses his personal view about the history of nanotechnology.

On 29 December 1959, Richard P. Feynman gave an after-dinner talk at an annual American Physical Society meeting, entitled "There's Plenty of Room at the Bottom."

One attendee later told science writer Ed Regis that the puzzled physicists in the room feared Feynman meant that "there are plenty of lousy jobs in physics."

Feynman said that he really wanted to discuss "the problem of manipulating and controlling things on a small scale." In short, a half-century ago he anticipated what we now call nanotechnology—the manipulation of matter at the level of billionths of a meter.

Some historians depict the speech as the start of this now-burgeoning field of research. Yet Feynman didn't use the word "nanotechnology" himself, and his lecture went for years almost entirely unmentioned in the scientific literature until the 1980s (Editor's note: Physics Today referred to it in 1979).

The story of how his talk was forgotten and then, decades later, inserted into the history of nanotechnology is worth understanding less because of what it tells us about the past than because of what it hints about the future, a future in which billions of dollars in research and development funds are at stake.

Related Physics Today article
Microscience: an overview

NYTimes.com: OmniVision has announced a new image sensor chip that uses a technique called BSI, or backside illumination, that basically turns the camera chip upside down so that the light is collected through the back of the chip. In a more typical image sensor, light has to pass through a series of layers on the image chip before reaching the sensor. BSI provides better performance, particularly in low-light conditions.

Both NASA and the National Security Agency have been using BSI image technology in satellites for years, but this OmniVision chip is one of the first made available to consumers.

The chip, which will most likely appear in a mobile phone, is capable of recording 14.6 megapixel single images, or full 60-frames-per-second 1080p high-definition video.

Related Link
OmniVision adopts backside illumination technology for CMOS imager (description of an earlier BSI chip)

The Guardian: What are chemists, physicists, and engineers working on in the quietest building in the world? The Guardian's Louise Tickle visit's Bristol University's new Centre for Nanoscience and Quantum Information to find out why improvements in energy efficiency using nanodiamonds require access to a quiet room.

Wired.com: Researchers have showed the first functional transistor made from a single molecule. The transistor, which has a benzene molecule attached to gold contacts, could behave just like a silicon transistor.

The molecule’s different energy states can be manipulated by varying the voltage applied to it through the contacts. And by manipulating the energy states, researchers were able to control the current passing through it.

ScienceNOW: In the world of nanotechnology, few things get as much billing as nanotubes. Experts say that these cylinders composed of one-molecule-thin sheets could someday be used in everything from superstrong jet engines to cancer cures. Now researchers think they've found a way to make large amounts of an elusive type of nanotube that could provide even more impressive applications.

Related Link
Very long single- and few-walled boron nitride nanotubes via the pressurized vapor/condenser method

ScienceNOW: Paper has been getting beat by electronics for years. But it may be about to stage a comeback. Researchers are reporting that they've made batteries and other energy-storage devices by printing layers of carbon nanotube–based ink atop standard photocopy paper. The result is a highly conductive sheet that can carry a charge and be easily incorporated into a flexible battery. Because of paper's low cost, that could help lower the price of batteries used in electric vehicles, wind farms, and other renewable sources.

New Scientist: Solar cells have an unfortunate habit of reflecting back much of the light that hits them, rather than converting it into electricity. A technique that peppers the cells' surface with nanoscale domes could curb this tendency and improve efficiency by as much as 25% (Nano Letters, DOI: 10.1021/nl9034237).

ScienceNOW: A new study has found that nanoscale materials, used in everything from medical imaging to cancer treatment, can damage genetic material in our bodies, feeding public fears.

But this particular study has little relevance to human exposure risks, experts say, and it is deeply flawed in other ways.

Nature: Two experiments that produce laser light by exploiting the collective wave-like motion of free electrons on a metal surface bring the science and technology of lasers into the realm of the nanoscale.

Daily Telegraph: The world's 'quietest' room opened its doors for the study of nanotechnology in Bristol.

The ''ultra-low vibration suite'', which cost £11m, allows scientists to manipulate atoms and molecules without the interference of environmental vibrations interrupting their work.

There is virtually no air movement inside the cutting edge laboratory, which is anchored to the rock foundation in the basement of the Nanoscience and Quantum Information Centre in Bristol.

The building's architecture prevents the penetration of echo and sound waves inside the building, despite its location in the Bristol city centre.

Meanwhile, its exterior panels are made from 'self-cleaning' glass, that uses nano-particles to break down dirt.

The Centre will be used for a range of experiments, from looking for solutions to greener power production to better ways to battle cancer.

NPR: Researchers in several laboratories are vying for the claim that they have produced the world's smallest lasers. The lasers are a thousand times smaller than the diameter of a human hair. Scientists hope they can be used to create even smaller and faster electronics, to study diseases, or possibly even to treat cancer from inside human cells.

2009 AIP Industrial Physics Forum: Thermal therapy is being used to kill cancer cells in tumors that other methods fail to eliminate, but there is the risk of overheating healthy cells, or not heating the tumor cells enough.

A new idea for improving thermal therapy was recently published in Proceeding of the National Academy of Sciences and presented at the AAPM session "Frontiers in Medical Physics," by Leo Xuanfeng Ding from Wake Forest University. Using multi-walled carbon nanotubes (MWCN's) Ding and his collaborators hope to make guided laser cancer removal safer and more effective.

The treatment injects cancer tumors with MWCN's, and uses a guided near infrared laser to heat them up and deliver a fatal temperature rise to the cancer cells. The laser pulse is low energy (3 W/cm2) and fast (30 seconds per dose). The team uses Magnetic Resonance Temperature Imaging, MRTI, to identify the tumor and then to monitor the tumor's temperature as well as the temperature of the surrounding tissue. Trials with mice showed a significant rise in the temperature of the cancer cells injected with the MWCN's, compared to without. And, the tumors were far less likely to come back.

Nature News: A set of little lenses is stoking a big debate amongst physicists. At issue is whether the tiny spheres are capable of beating the so-called diffraction limit, beyond which no lens can, in theory, work.

CNET News: Researchers at the Massachusetts Institute of Technology have developed a fabric made of a mesh of light-sensitive fibers that collectively act like a rudimentary camera. The fibers, which each can detect two frequencies of light, produced signals that when amplified and processed by a computer reproduced an image of a smiley face near the mesh.

"This is the first time that anybody has demonstrated that a single plane of fibers, or 'fabric,' can collect images just like a camera but without a lens," said Yoel Fink, an associate professor of materials science, who along with colleagues described the approach in a the journal Nano Letters.

Related Link
Exploiting Collective Effects of Multiple Optoelectronic Devices Integrated in a Single Fiber

Science News: Concrete creeps. And now scientists think they know why.

New measurements suggest that the rearrangement of nano-sized concrete particles is responsible for the way buildings, bridges, and other load-bearing concrete structures deform over time, a process technically known as “creep.” The new insight could allow engineers to make stronger and longer-lasting concrete, researchers report in a study to be published online in the Proceedings of the National Academy of Sciences.

Related Link
Nanogranular origin of concrete creep

Exploration magazine: Vanderbilt University physicists have found a way to make nanoparticle films strong enough so they don't disintegrate at the slightest touch.

Nanoparticles—ultrafine particles with diameters less than 100 nanometers—typically consist of an inorganic core coated with a thin layer of organic molecules.

These particles are not very sticky so they don't form coherent thin films unless they are encapsulated in a polymer coating or mixed with molecules called chemical "cross-linkers" that act like glue to stick the nanoparticles together. This makes the film expensive.

The Vanderbilt University physicists added a spun-cast layer of polymer to the electrodes that serves as a pattern that organizes the nanoparticles as they are deposited in a technique called electrophoretic deposition. Then, after the deposition process is completed, they dissolve (sacrifice) the polymer layer to free the nanoparticle film.

Related Link
Sacrificial layer electrophoretic deposition of freestanding multilayered nanoparticle films

Nature News: Nanocrystals called quantum dots have promised to revolutionize display technologies, solar power and biological imaging for more than a decade. Yet the quantum-dot market has remained small, with a handful of companies selling dots directly to researchers, using the particles to develop their own products or licensing their technologies to partners.

"Quantum dots have been around for quite a while, but they're taking a really long time to mature," says David Hwang of the market-analysis company Lux Research in New York. A key barrier is price: quantum dots can cost anywhere from US$3,000 to $10,000 per gram, restricting their use to highly specialized applications.

But industry analysts are now predicting extremely rapid growth for the market over the next few years, driven by demand for energy-efficient displays and lighting, and enabled by cheaper, more efficient manufacturing processes. In September 2008, market-research company BCC Research of Wellesley, Massachusetts, predicted that the market for products relying on quantum dots would grow from $28.6 million in 2008 to $721 million by 2013, with particularly rapid growth in the optoelectronics sector from 2010.

CNET News: IBM already had technology that could measure extremely subtle forces among atoms, but a nanotechnology development at the company's Zurich Research Laboratory shows a new level of sensitivity: the ability to distinguish positively charged atoms from those that are neutral or negatively charged.

The atomic force microscope maps what's below by detecting subtle changes in forces of attraction.

Researchers at the Zurich lab, along with colleagues at the University of Regensburg and Utrecht University, used an atomic force microscope (AFM) with a tuning-fork detector arrangement on the tip of its probe to distinguish among gold atoms that were positively charged, neutral, or negatively charged. The researchers describe their approach in the June 12 issue of Science.

Related Press Release
IBM scientists directly measure charge states of atoms using an atomic force microscope

Related article
Novel Probes for Molecular Electronics

Science: The ability to observe individual chemical reactions in real time is reshaping our understanding of molecular processes, revealing subtleties previously hidden in ensemble averages. For example, single-molecule fluorescence detection methods have revolutionized optical microscopy and in situ studies of chemical and biological systems. Liquid cell in situ transmission electron microscopy (TEM) is poised to write a new chapter in the solution synthesis and processing of materials. Haimei Zheng and colleagues use a TEM liquid cell that allows liquids to be examined within the vacuum environment of a TEM in an elegant experiment that uncovers dynamic processes in the growth of platinum (Pt) nanocrystals.

Related Link
Observation of Single Colloidal Platinum Nanocrystal Growth Trajectories

The New York Times: Nanotechnology's image is sleek, modern, and clean. But that's not its reality.

Turns out that designing and manufacturing materials so small that 100,000 of them can fit comfortably on the width of a hair strand absorbs tremendous amounts of energy and is anything but neat.

Nature: Electricity flexes strong, bendy aerogel.

The developers of 'photonic ink' (P-Ink) say that the material could be used in electronic books or advertising displays.

CNET: A variety of off-grid devices use the wind, the sun, or fuel cells to power up small electronics. But what if you could charge your cell phone just by talking into it, eliminating the need for batteries or cords?

Environmental News Network: The Europeans are serious about nanotechnology to wean countries off using fossil fuels in the next century. There´s considerable interest in setting up a solar grid that is global because the sun consistently shines on some part of the planet.

Science:

Investor's Business Daily: A report released yesterday from the Woodrow Wilson International Center for Scholars contends that the White House should direct federal agencies to apply existing laws more effectively and strengthen nanotech oversight.

The study's lead author, J. Clarence "Terry" Davies, is a scientific adviser to the Washington, D.C., group who served as an administrator for the Environmental Protection Agency under the first President Bush.

He says clearer oversight would not only help to protect health and the environment, but also drive more nanotech investment.

AFP: Scientists across Russia are setting their minds to new inventions to net some of the billions of state dollars being poured into the field of nanotechnology. But they remain sceptical after years of neglect by the government.

Nature: Different material options for high-temperature superconductivity— conduction of electricity with little or no resistance at 'practical' temperatures — have arrived. Iron compounds are the latest thing.

National Geographic: Nanotech fabric that can harvest energy from motion could one day lead to clothing that can power portable electronics, researchers say.

Nature: The future of the video display is both flexible and transparent. Finding a material for the attendant electronics that is small-scale, bendy and see-through is a tall order — but a promising candidate is emerging.

AZoNano.com: For the first time ever, an exclusive, comprehensive platform of the entire Israeli Nanotech eco-system has been launched. It is an all inclusive portal, mapping the entire Nanotech ecosystem, including over 300 researchers, 80 companies and 40 governmental and nonprofit organizations.

EETimes: India's national nanotechnology program is rolling out as the first of three Institutes for Nano Science and Technology is inaugurated under the federal government's $250 million national initiative in support of nanotechnological research. The regional government of Karnataka partner with the government in the establishment of the first institute, eager to promote Bengaluru a global hub for nanotechnology as in the past it has promoted it as a software hub.

The researchers have used these electrodes to create a flexible light-emitting device. Both the anode and cathode are transparent which, even when repeatedly bent, twisted, rolled or folded completely over, continue to conduct electricity without losing any notable properties.

Nature: Radio waves turn injected carbon into heat bombs against tumours.

CNET: University of California at Berkeley's nanoradio might be a 100 billion times smaller than the first commercial radios, but it plays the hits that never die.

Wired: Back in the mid-1980s, a joke made the rounds that the Kremlin was preparing a major announcement: After a decade-long top-secret crash program, socialist science had succeeded in building the world's largest microprocessor.

Ertl's research laid the foundation of modern surface chemistry, which has helped explain how fuel cells work, how catalytic converters clean up car exhaust and even why even why iron rusts, the Royal Swedish Academy of Sciences said.

Ertl, who won the prize on his 71st birthday, told reporters that it ''is the best birthday present that you can give to somebody.''

''I am speechless,'' Ertl told The Associated Press from his office in Berlin. ''I was not counting on this.''

Related Web sites
The Nobel Prize in Chemistry 2007
German Wins Nobel Chemistry Prize, Associated Press
Nobel Prize in Chemistry Won by Gerhard Ertl, NPR
Telephone interview with Gerhard, Nobel Foundation.
Gerhard Ertl's web site

Fert and Gruenberg helped pioneer the making of semiconductor stacks consisting of alternating thin layers of magnetic and non-magnetic atoms needed to produce the GMR effect. GMR is a prominent example of how quantum effects (a large electrical response to a tiny magnetic input) come about through confinement (the atomic layers being so thin.); that is, atoms interact differently with each other when they are confined to a tiny volume or a thin plane. All these magnetic interactions involve the spin of an electron. Spin is a quantum attribute that shouldn’t be associated too closely in the mind with the electron literally spinning (in the way that a top spins). Still more innovative technology can be expected through quantum effects depending on electrons’ spin. Most of the electronics industry is based on manipulating the charges of electrons moving through circuits. But the electrons’ spins might also be exploited to gain new control over data storage and manipulation. Spintronics is the general name for this branch of electronics.

Related Physics Today articles
Layered Magnetic Structures: History, Highlights, Applications, May 2001, page 31
Basic Research in the Information Technology Industry, Jul 2003
Magnetic Semiconductors Enable Efficient Electrical Spin Injection, April 2000, page 21
Physics Today, April 1995 (available November 1)

Related web sites
2007 Nobel Prize site
Wolf Prize announcement
Peter Gruenberg
Recent papers by Fert and Gruenberg

Related news stories
Magnetic Effect Nets a Nobel, Science
Physics of Hard Drives Wins Nobel, New York Times
Magnetic Effect Nets a Nobel, Science
Reuters
Physics Nobel Goes to German, Frenchman, Wired News
Disk technology takes Nobel Prize, BBC
Europeans Win Nobel Prize for Physics, NPR
A little magnetism wins physics Nobel, The Australian

Consider the career of Mukhles Sowwan, who founded the Nanotechnology Research Laboratory at Al-Quds University in East Jerusalem. The lab is the first nanotech center in East Jerusalem and the West Bank, according to Dr. Sowwan, a Palestinian who has a doctorate in solid-state nanophysics. He also believes that it is the first such lab at an Arab institution in the Middle East.

The lab pursues ground-breaking research under conditions that would bewilder most American and European technologists. But although Dr. Sowwan is its guiding spirit, it would not exist except for the generosity of European donors, the stubborn internationalism of a United Nations organization and the help of Dr. Sowwan’s mentor, who happens to be an Israeli physicist at Hebrew University in West Jerusalem.

Nature: Parliament approves nanotechnology initiative.

San Francisco Chronicle: The future is now: Nanotechnology is already in hundreds of everyday products, but questions remain about long-term environmental effects

The New York Times: DuPont and Environmental Defense, one of the nation’s largest environmental groups, plan to release jointly developed guidelines today for evaluating the safety and environmental risks of nanotechnology products.

Milwaukee Journal Sentinel: Scientists try to harness architecture of microscopic diatoms for commercial ventures

Science: A group of chemists reports finding a way to assemble tiny metal particles into a substance that can be shaped and fired--at little more than room temperature

BBC: The UK government has failed to fund adequate research into potential risks posed by developing nanotechnology, a report by leading advisors has warned.

Nanotechwire.com: The U.S. Department of Defense (DoD) has awarded a team of nine scholars from six universities a grant of $6 million over five years to exploit precise biological assembly techniques for the study of quantum physics in nanoparticle arrays. This research will produce a fundamental understanding of quantum electronic systems that could impact future electronics.

AZoNano.com: The boom in Finnish nanotechnology is uncovered by the 'Nanotechnology in Finnish Industry' survey. The biannual survey studied the evolution of the Finnish nanotechnology scene in the period 2004-2006. The 2006 survey identified 129 Finnish companies that either had commercial products or research activities focused on nanotechnology, or who had participated in the Tekes FinNano technology programme. The previous 2004 survey had found 61 companies that had activities related to nanotechnology.

BBC: Prototypes of microscopic engines that could power molecular machines have been brewed up in a Scottish laboratory.

European Design Engineer: Researchers at the University of California, Santa Barbara, USA, led by Shuji Nakamura--who invented the blue laser--have achieved lasing operation in nonpolar gallium nitride (GaN) semiconductors and demonstrated the world's first nonpolar blue-violet laser diodes.

The Future of Things (TFOT): A new, safer type of Li-Ion nanobattery that might help prevent future fires and explosions related to conventional Li-Ion battery use has been developed by researchers at Tel Aviv University. These nanobatteries should also prove useful for various micro devices used for medical, military and a range of other applications.

The New York Times: Scientists who are trying to develop molecular machines have spent a lot of time reinventing the wheel — literally making wheels and gears from just a few atoms. The eventual goal is to use such components in nanoscale devices that can do useful work inside living tissue, perhaps, or as part of a tiny nonelectronic computer.

MSNBC: The use of subatomic materials as microscopic building blocks for thousands of consumer products has turned into a big business so quickly that few are monitoring the so-called nanotechnology's effects on health and the environment.

Technology Review: Artificial muscles made from carbon nanotubes are 100 times stronger than human muscles.

AZoNano.com: Silicon nanowires can help to further reduce the size of microchips. Scientists at the Max Planck Institute for Microstructure Physics in Halle have for the first time developed single crystal silicon nanowires that fulfil the key criteria to this end. The researchers used aluminium as a catalyst to grow the nanowires. To date, scientists have usually deployed gold for this purpose. However, even traces of the precious metal have a drastically detrimental effect on the function of semiconductor components. This is not the case with other metals, which catalyse the process, but only at temperatures that would not enable economically viable processes. On the other hand, aluminium is an effective catalyst even at relatively low temperatures and does not impair the quality of electronic components

Nature: The pursuit of responsible nanotechnologies can be tackled through a series of grand challenges, argue Andrew D. Maynard and his co-authors.

Nature: One US nanotechnology start-up has hit the jackpot — but for others the prospect of such overnight success seems remote. Colin Macilwain reports.

Azonano.com: Current techniques for creating carbon nanotubes result in a mass of nanotubes with different electronic and structural properties. Researchers from Northwestern University have developed a method for sifting and automatically grading the nanotubes by exploiting the buoyant densities of nanotubes. These densities are a function of their size and electronic behavior. The nanotubes are dropped into water coated by soap-like molecules called surfactants. A centrifuge spins the liquid to high speed. By carefully choosing the surfactants utilized during ultracentrifugation, the researchers found that carbon nanotubes could be sorted by diameter and electronic structure. The technique can be easily scaled up to industrial production. The results were published in Nature Nanotechnology.

Science: Nanotechnology observers are split over the best way to ensure that the up-and-coming industry remains safe for both people and the environment.

Technology Review: HP researchers have developed a cheap way to make nanoparticle arrays that could lead to precise chemical sensors.

Nature: The use of X-rays to construct three-dimensional tomographic images is well established in medicine. The same principle is being extended to the nanoscale, bringing us startlingly accurate pictures of tiny objects.

ZDNet: Scientists have discovered a new method for detecting deadly pathogens like Anthrax or smallpox almost immediately after they've been released into the air.

BBC: Robotic hands that have the same senstivity as the human hand to touch have been unveiled in a paper in Science magazine says the BBC. The resolution of the sense of touch on the human fingertip is about 40 microns, and previously the best robotic hand had a resolution of millimetres. The new device should aid minimally invasive surgical techniques.

Guardian Unlimited: Scientists have been working on minuscule nanotechnology test tubes for a long time - tiny little packets of chemicals that can be injected into the body, before pouring out to react with other substances like cancers.

AZoNano.com: The University of Massachusetts Amherst will host one of the nation’s elite nanotechnology centers, the National Science Foundation (NSF) announced today, awarding $16 million to establish the Center for Hierarchical Manufacturing. Combined with state matching funds, the investment will accelerate research and production of ultra-tiny devices, creating new manufacturing opportunities and stimulating economic development. The announcement was made at a State House news conference.