Friday, July 8, 2011

This week in nanotechnology - July 8, 2011

A discovery in semiconductor nanowire laser technology could potentially do everything from kill viruses to increase storage capacity of DVDs. Ultraviolet semiconductor diode lasers are widely used in data processing, information storage and biology. Their applications have been limited, however, by size, cost and power. The current generation of ultraviolet lasers is based on a material called gallium nitride, but researchers have made a breakthrough in zinc oxide nanowire waveguide lasers, which can offer smaller sizes, lower costs, higher powers and shorter wavelengths.

The making of three-dimensional nanostructured materials has become a fertile area of research, producing materials that are useful for electronics, photonics, phononics and biomedical devices. But the methods of making such materials have been limited in the 3-D complexity they can produce. Now, an MIT team has found a way to produce more complicated structures by using a blend of current "top-down" and "bottom-up" approaches. Their new 3D nanofabrication method makes it possible to manufacture complex multi-layered solids all in one step.

A high-temperature superconductor can now be switched on and off within a trillionth of a second. A team of physicists has realized an ultrafast superconducting switch by using intense terahertz pulses. This experiment opens up the possibility to discover more about the still unsettled cause of this type of superconductivity, and also hints at possible applications for ultrafast electronics in the future.
Ultrafast switch for superconductors
The superconducting transport between the layers of a cuprate crystal (three layers, red and blue spheres represent the oxygen and copper atoms respectively) is controlled with an ultrashort terahertz pulse (yellow in the background). The three-dimensional superconductivity can thus be switched on and off very quickly (orange spheres represent electrons).

Observation of a scientific rule being broken can sometimes lead to new knowledge and important applications. Such would seem to be the case when scientists created artificial molecules of semiconductor nanocrystals and watched them break a fundamental principle of photoluminescence known as Kasha's rule. Named for chemist Michael Kasha, who proposed it in 1950, Kasha's rule holds that when light is shined on a molecule, the molecule will only emit light (fluorescence or phosphorescence) from its lowest energy excited state. This is why photoluminescent molecules emit light at a lower energy than the excitation light. While there have been examples of organic molecules, such as azulene, that break Kasha's rule, these examples are rare. Highly luminescent molecular systems crafted from quantum dots that break Kasha's rule have not been reported – until now.

Researchers have discovered a way to capture and harness energy transmitted by such sources as radio and television transmitters, cell phone networks and satellite communications systems. By scavenging this ambient energy from the air around us, the technique could provide a new way to power networks of wireless sensors, microprocessors and communications chips.

Friday, July 1, 2011

This week in nanotechnology - July 1, 2011

Scientists in Austria have developed light-detectors made of graphene and analyzed their astonishing properties. They demonstrated how remarkably fast graphene converts light pulses into electrical signals. This could considerably improve date exchange between computers.

Physicists working at the University of California, Santa Barbara and the University of Konstanz in Germany have developed a breakthrough in the use of diamond in quantum physics, marking an important step toward quantum computing. They were able to coax the fragile quantum information contained within a single electron in diamond to move into an adjacent single nitrogen nucleus, and then back again using on-chip wiring.

Future computers may rely on magnetic microprocessors that consume the least amount of energy allowed by the laws of physics, according to an analysis by University of California, Berkeley, electrical engineers. Today's silicon-based microprocessor chips rely on electric currents, or moving electrons, that generate a lot of waste heat. But microprocessors employing nanometer-sized bar magnets – like tiny refrigerator magnets – for memory, logic and switching operations theoretically would require no moving electrons.
Nanomagnetic computers use tiny bar magnets to store and process information
Nanomagnetic computers use tiny bar magnets to store and process information. The interactions between the polarized, north-south magnetic fields of closely spaced magnets allow logic operations like those in conventional transistors.

Scientists have discovered fundamental steps of charging of nano-sized water droplets and unveiled the long-sought-after mechanism of hydrogen emission from irradiated water. It has been known since the early 1980s that while single electrons may attach to small water clusters containing as few as two molecules, only much larger clusters may attach more than single electrons. Size-selected, multiple-electron, negatively-charged water clusters have not been observed — until now.

In science and industry, polymer nanocomposites are increasingly regarded as materials that will significantly help to define progress in the 21st century. They consist of a polymer matrix and of nanoparticles which are inserted into the matrix as filler materials. A research group in Germany has now developed a process which opens an avenue for the production of new, completely miscible nanocomposites. These materials represent an extremely varied potential for technological innovations.

Friday, June 24, 2011

This week in nanotechnology - June 24, 2011

For decades, researchers have been working to develop nanoparticles that deliver cancer drugs directly to tumors, minimizing the toxic side effects of chemotherapy. However, even with the best of these nanoparticles, only about 1 percent of the drug typically reaches its intended target. Researchers have now designed a new type of delivery system in which a first wave of nanoparticles homes in on the tumor, then calls in a much larger second wave that dispenses the cancer drug.

Scientists have established a biomimetic nanopore that provides a unique test and measurement platform for the way that proteins move into a cell's nucleus. This artificial nanopore is functionalized with key proteins which mimicks the natural nuclear pore and also shows the same selectivity that is found in natural pores.

The eye of the peacock mantis shrimp has led to a two-part waveplate that could improve CD, DVD, blu-ray and holographic technology, creating even higher definition and larger storage density. A team of engineers developed a method to produce periodically multilayered materials, similar to the lens in the peacock mantis shrimp, that are suitable for waveplates in the visual light spectrum and cannot delaminate because they are manufactured as one piece. This waveplate is made of two layers of nanorods that are structurally similar to those in the eye of the peacock mantis shrimp.
peacock mantis shrimp
Peacock mantis shrimp.

Turning carbon dioxide directly into graphene? Yup! Researchers report a new method that converts carbon dioxide directly into few-layer graphene (less than 10 atoms in thickness) by burning pure magnesium metal in dry ice. This synthetic process can be used to potentially produce few-layer graphene in large quantities.

Research into the use of nanotechnology in treating stroke has produced evidence of significant motor function recovery. The use of carbon nanotubes to deliver short strands of RNA – called siRNA – and induce gene silencing of specific target areas in the brain responsible for motor functions has allowed scientists to 'switch off' proteins that contribute to neuronal tissue loss. This collaborative and highly multidisciplinary project offers the possibility of a new treatment for stroke.

Improving concrete performance with nanotechnology: Every day, concrete structures crack and erode prematurely due to Alkali Silica Reactivity (ASR), a chemical reaction that causes fissures in the material as it sets. Research into the optimal use of nano-silica will create a new concrete mixture that will result in longer-lasting buildings, roadways, sidewalks, stairs, sewers, and dams.
Nanocoated 'super sand' for better purification of drinking water: Scientists have developed a way to transform ordinary sand — a mainstay filter material used to purify drinking water throughout the world — into a 'super sand' with five times the filtering capacity of regular sand by coating it with graphite oxide nanosheets.

Friday, June 17, 2011

This week in nanotechnology - June 17, 2011

A new generation of high speed, silicon-based information technology has been brought a step closer - scientists demonstrate first telecommunications wavelength quantum dot laser grown on a silicon substrate.

New engineering research at the University of Pennsylvania demonstrates that polaritons have increased coupling strength when confined to nanoscale semiconductors. This represents a promising advance in the field of photonics: smaller and faster circuits that use light rather than electricity.

A nanoscale grapevine with hydrogen grapes could someday provide your car's preferred vintage of fuel. Rice University researchers have determined that a lattice of calcium-decorated carbyne has the potential to store hydrogen at levels that easily exceed Department of Energy (DOE) goals for use as a "green" alternative fuel for vehicles.
Hydrogen adsorption on calcium-decorated carbyne chain
Hydrogen adsorption on calcium-decorated carbyne chain.

The world's first three-dimensional plasmon rulers, capable of measuring nanometer-scale spatial changes in macromolecular systems, could provide scientists with unprecedented details on such critical dynamic events in biology as the interaction of DNA with enzymes, the folding of proteins, the motion of peptides or the vibrations of cell membranes.

Team reports scalable fabrication of self-aligned graphene transistors, circuits. The research opens a rational pathway to scalable fabrication of high-speed, self-aligned graphene transistors and functional circuits and it demonstrates for the first time a graphene transistor with a practical (extrinsic) cutoff frequency beyond 50 GHz.

Friday, June 10, 2011

This week in nanotechnology - June 10, 2011

A radically new approach to the design of batteries, developed by researchers at MIT, could provide a lightweight and inexpensive alternative to existing batteries for electric vehicles and the power grid. The technology could even make "refueling" such batteries as quick and easy as pumping gas into a conventional car. The new battery relies on an innovative architecture called a semi-solid flow cell, in which solid particles are suspended in a carrier liquid and pumped through the system.

Microscopy with a quantum tip: The heart of a scanning probe microscope is a moveable, suspended tip, which, like the needle on a record player, reacts to small height variations on the surface, and turns these into signals that can be displayed on a computer. Researchers have now been able to create this tip, not out of solid material, but out of an ultra-cold, dilute gas of atoms. This "quantum tip" can be precisely positioned and enables the probing of nanostructured surfaces. With this method, more accurate measurements of the interactions between atoms and surfaces are possible and further cooling of the probe tip gives rise to a so-called Bose-Einstein condensate, which allows a significant increase in the resolution of the microscope.

IBM researchers announced the first integrated circuit fabricated from wafer-size graphene, and demonstrated a broadband frequency mixer operating at frequencies up to 10 gigahertz (10 billion cycles/second). This result opens up possibilities of achieving practical graphene technology with more high-performance, radio-frequency communication devices and is also a major milestone for the Carbon Electronics for RF Applications (CERA) program, funded by DARPA.
Optical image of a completed graphene integrated circuit
Optical image of a completed graphene integrated circuit (IC) including contact pads. The probes for testing the circuit (P1-P4) are also shown. The scale bar is 100 ┬Ám.

You can run but you can't hide - Nanotechnology is key to recovering usable fingerprints from old evidence. Researchers have made an important step towards recovering usable fingerprints from old evidence and surfaces long considered too difficult by crime scene investigators. The new method uses antibodies designed to target amino acids and can detect aged, dry and weak fingerprints that can't be captured using traditional fingerprinting methods.

Electrical engineers have long been toying with the idea of designing biological molecules that can be directly integrated into electronic circuits. University of Pennsylvania researchers have developed a way to form these structures so they can operate in open-air environments, and, more important, have developed a new microscope technique that can measure the electrical properties of these and similar devices.

Friday, June 3, 2011

This week in nanotechnology - June 3, 2011

Graphene is a two-dimensional honeycomb of carbon, just one atom thick, whose intriguing electronic properties include very high electron mobility and very low resistivity. Graphene is so sensitive to its environment, however, that these remarkable attributes can be wrecked by interference from nearby materials. Finding the best substrate on which to mount graphene is critical if graphene devices are ever to become practical. Researchers have joined forces to examine the best substrate candidates for preserving graphene's intrinsic properties.

The creation of a new quasiparticle called the "hybrid plasmon polariton" may throw open the doors to integrated photonic circuits and optical computing for the 21st century. Researchers with the Berkeley Lab have demonstrated the first true nanoscale waveguides for next generation on-chip optical communication systems.

In many ways, life is like a computer. An organism's genome is the software that tells the cellular and molecular machinery—the hardware—what to do. But instead of electronic circuitry, life relies on biochemical circuitry—complex networks of reactions and pathways that enable organisms to function. Now, researchers at Caltech have built the most complex biochemical circuit ever created from scratch, made with DNA-based devices in a test tube that are analogous to the electronic transistors on a computer chip.
A wiring diagram specifying a system of 74 DNA molecules
A wiring diagram specifying a system of 74 DNA molecules that constitute the largest synthetic circuit of its type ever made. The circuit computes the square root of a number up to 15 and rounds down to the nearest integer (the discrete square root of a four-bit integer).

A simple technique for stamping patterns invisible to the human eye onto a special class of nanomaterials provides a new, cost-effective way to produce novel devices in areas ranging from drug delivery to solar cells. The new method works with materials that are riddled with tiny voids that give them unique optical, electrical, chemical and mechanical properties. Imagine a stiff, sponge-like material filled with holes that are too small to see without a special microscope.

University of Houston researchers have developed a method for creating single-crystal arrays of graphene, an advance that opens the possibility of a replacement for silicon in high-performance computers and electronics.

Friday, May 27, 2011

This week in nanotechnology - May 27, 2011

Electrical engineers at Duke University have determined that unique man-made materials should theoretically make it possible to improve the power transfer to small devices, such as laptops or cell phones, or ultimately to larger ones, such as cars or elevators, without wires. This advance is made possible by the recent ability to fabricate exotic composite materials known as metamaterials, which are not so much a single substance, but an entire man-made structure that can be engineered to exhibit properties not readily found in nature.

Being able to isolate individual molecules like DNA base pairs, which are just two nanometers across, is incredibly expensive and difficult to control. Now a team led by Yale University researchers has proven that isolating individual charged particles, like DNA molecules, is indeed possible using a method called "Paul trapping," which uses oscillating electric fields to confine the particles to a space only nanometers in size.
A single nanoparticle trapped between four microelectrodes
A single nanoparticle trapped between four microelectrodes

Physicist achieves measurement milestone down to the yoctonewton level. This is an incredibly small force - about a million million billion times smaller than the force exerted by a feather lying on a table. And the measurement is a thousand times more sensitive than anything previously possible.

A step closer to mass-manufacturing graphene for nanoelectronics: Researchers have developed a method for creating single-crystal arrays of graphene, an advance that opens up the possibility of a replacement for silicon in high-performance computers and electronics. The new findings represent an advance toward perfecting a method for manufacturing large quantities of single crystals of the material, similar to the production of silicon wafers.

At the forefront of nanotechnology, researchers design miniature machines to do big jobs, from treating diseases to harnessing sunlight for energy. But as they push the limits of this technology, devices are becoming so small and sensitive that the behavior of individual atoms starts to get in the way. Now Caltech researchers have, for the first time, measured and characterized these atomic fluctuations - which cause statistical noise - in a nanoscale device.

Friday, May 20, 2011

This week in nanotechnology - May 20, 2011

Victims of third-degree burns and other traumatic injuries endure pain, disfigurement, invasive surgeries and a long time waiting for skin to grow back. Improved tissue grafts designed by Cornell scientists that promote vascular growth could hasten healing, encourage healthy skin to invade the wounded area and reduce the need for surgeries.

Looking inside nanomaterials in three dimensions: Most solid materials are composed of millions of small crystals, packed together to form a fully dense solid. The orientations, shapes, sizes and relative arrangement of these crystals are important in determining many material properties. The newly developed technique allows 3D mapping of the crystal structure inside a material down to nanometer resolution, and can be carried out using a transmission electron microscope, an instrument found in many research laboratories.
3D mapping of the crystal structure inside a material down to nanometer resolution
3D mapping of the crystal structure inside a material down to nanometer resolution.

By combining high pressure with high temperature, Livermore researchers have created a nanocyrstalline diamond aerogel that could improve the optics for something as big as a telescope or as small as the lenses in eyeglasses.

A recent study at the National Institute of Standards and Technology (NIST) may have revealed the optimal characteristics for a new type of computer memory now under development. The work aims to optimize nanowire-based charge-trapping memory devices, potentially illuminating the path to creating portable computers and cell phones that can operate for days between charging sessions.

It sounds like hype from a late-night infomercial: It can twist and bend without breaking! And wait, there's more: It could someday help you fend off disease! Scientists from several institutions derived atomic-scale resolution structures of the cell's protein-making machine, the ribosome, at key stages of its job. Many antibiotics target the ribosomes of disease-causing microbes at precisely this stage. The high-resolution structures could allow scientists to develop antibiotics that better target this cellular Achilles' heel, perhaps leading to drugs that are less susceptible to resistance.

Friday, May 13, 2011

This week in nanotechnology - May 13, 2011

Scientists at the University of California, Berkeley, have demonstrated a new technology for graphene that could break the current speed limits in digital communications. The team built a tiny optical device that uses graphene, a one-atom-thick layer of crystallized carbon, to switch light on and off. This switching ability is the fundamental characteristic of a network modulator, which controls the speed at which data packets are transmitted.

What limits the behaviour of a carbon nanotube? This is a question that many scientists are trying to answer. Physicists at University of Gothenburg, Sweden, have now shown that electromechanical principles are valid also at the nanoscale. In this way, the unique properties of carbon nanotubes can be combined with classical physics – and this may prove useful in the quantum computers of the future.

MIT researchers have created a new detector so sensitive it can pick up a single molecule of an explosive such as TNT. To create the sensors, chemical engineers coated carbon nanotubes with protein fragments normally found in bee venom. This is the first time those proteins have been shown to react to explosives, specifically a class known as nitro-aromatic compounds that includes TNT.
Coated carbon nanotube sensors can detect single molecule of an explosive
The sensor uses carbon nanotubes covered in protein fragments to detect even a single molecule of an explosive, such as the TNT molecule shown here.

In a step toward engineering ever-smaller electronic devices, scientists at the Brookhaven National Laboratory have assembled nanoscale pairings of particles that show promise as miniaturized power sources. Composed of light-absorbing, colloidal quantum dots linked to carbon-based fullerene nanoparticles, these tiny two-particle systems can convert light to electricity in a precisely controlled way.

Friday, May 6, 2011

This week in nanotechnology - May 6, 2011

With the creation of a 3-D nanocone-based solar cell platform, a team led by Oak Ridge National Laboratory's Jun Xu has boosted the light-to-power conversion efficiency of photovoltaics by nearly 80 percent. The technology substantially overcomes the problem of poor transport of charges generated by solar photons. These charges – negative electrons and positive holes – typically become trapped by defects in bulk materials and their interfaces and degrade performance.

A data memory can hardly be any smaller: researchers have stored quantum information in a single atom. The researchers wrote the quantum state of single photons, i.e. particles of light, into a rubidium atom and read it out again after a certain storage time. This technique can be used in principle to design powerful quantum computers and to network them with each other across large distances.

MIT chemical engineers have designed a new type of drug-delivery nanoparticle that exploits a trait shared by almost all tumors: They are more acidic than healthy tissues. Such particles could target nearly any type of tumor, and can be designed to carry virtually any type of drug. Like most other drug-delivering nanoparticles, the new MIT particles are cloaked in a polymer layer that protects them from being degraded by the bloodstream. However, the team designed this outer layer to fall off after entering the slightly more acidic environment near a tumor.
cloaked nanoparticle
The outer layer of this nanoparticle (in yellow) falls off in an acidic environment.

An international team of plasmonics researchers has developed a novel type of nanoantennas that could one day lead to advances in security applications for the detection of drugs and explosives. Nanoantennas work in much the same way as regular antennas, except they collect light instead of radio waves and are millions of times smaller.

New research paves way for the nanoscale self-assembly of organic building blocks, a promising new route towards the next generation of ultra-small electronic devices. Ring-like molecules with unusual five-fold symmetry bind strongly to a copper surface, due to a substantial transfer of charge, but experience remarkably little difficulty in sideways diffusion, and exhibit surprisingly little interaction between neighbouring molecules. This unprecedented combination of features is ideal for the spontaneous creation of high-density stable thin films, comprising a pavement of these organic pentagonal tiles, with potential applications in computing, solar power and novel display technologies.

Friday, April 29, 2011

This week in nanotechnology - April 29, 2011

Scientists have created a single-electron transistor that provides a building block for new, more powerful computer memories, advanced electronic materials, and the basic components of quantum computers. The transistor's central component – an island only 1.5 nanometers in diameter – operates with the addition of only one or two electrons. That capability would make the transistor important to a range of computational applications, from ultradense memories to quantum processors, powerful devices that promise to solve problems so complex that all of the world's computers working together for billions of years could not crack them.

Nanotechnology paper is stronger than steel: Graphene paper is a material that can be processed, reshaped and reformed from its original raw material state - graphite. Compared to steel, the prepared graphene paper is six times lighter, five to six times lower density, two times harder with 10 times higher tensile strength and 13 times higher bending rigidity.

Researchers inject nanofiber spheres carrying cells into wounds to grow tissue: for the first time, scientists have made star-shaped, biodegradable polymers that can self-assemble into hollow, nanofiber spheres, and when the spheres are injected with cells into wounds, these spheres biodegrade, but the cells live on to form new tissue.
Nanofibrous hollow microspheres
Nanofibrous hollow microspheres

With its promise of superfast computers and ultrapowerful optical microscopes among the many possibilities, plasmonics has become one of the hottest fields in high-technology. However, to date plasmonic properties have been limited to nanostructures that feature interfaces between noble metals and dielectrics. Now, researchers with the Berkeley Lab have shown that plasmonic properties can also be achieved in the semiconductor nanocrystals known as quantum dots. This discovery should make the field of plasmonics even hotter.

Boosting medicine with nanotechnology strengthens drug cocktail many times over. Researchers describe silica nanoparticles about 150 nanometers in diameter as honeycombed with cavities that can store large amounts and varieties of drugs. The enormous capacity of the nanoporous core, with its high surface area, combined with the improved targeting of an encapsulating lipid bilayer, permit a single 'protocell' loaded with a drug cocktail to kill a drug-resistant cancer cell.

Researchers at MIT have found a way to make significant improvements to the power-conversion efficiency of solar cells by enlisting the services of tiny viruses to perform detailed assembly work at the microscopic level. Researchers found that a genetically engineered version of a virus called M13, which normally infects bacteria, can be used to control the arrangement of carbon nanotubes on a surface, keeping the tubes separate so they can't short out the circuits, and keeping the tubes apart so they don't clump.

Saturday, April 16, 2011

This week in nanotechnology - April 15, 2011

Are we only a hop, skip and jump away from controlled molecular motion? We may very well be, according to researchers. Controlling how molecules move on surfaces could be the key to more potent drugs that block the attachment of viruses to cells, and will also speed development of new materials for electronics and energy applications.

Researchers at the University of Sheffield have discovered a new way of making small molecules self-assemble into complex nanopatterns, which will push the limits of what is possible in "bottom-up" methods of nanopatterning for advanced functional materials through molecular self-assembly. The study opens the way to new methods of producing `bottom-up´ ultra-small electronic and photonic integrated circuits. This would mean that instead of the expensive and slow electron, ion-beam or X-ray lithography, the molecules would assemble and form the desired patterns themselves.

Creating artificial structures from DNA is the objective of DNA nanotechnology. This new discipline, which combines biology, physics, chemistry and material science makes use of the ability of the natural DNA-strains' capacity for self assembly. Smileys or small boxes, measuring only 10s of nanometers were created from DNA in a drop of water. As part of the experiments, researchers were able to create two rings of DNA only 18 nanometers in size, and to interlock them like two links in a chain.
The world's smallest wedding rings are built up by two interlocked DNA-strands
The world's smallest wedding rings are built up by two interlocked DNA-strands.

When a drop falls on a lotus flower it remains on the surface without wetting it. This is due, firstly, to the chemical components of the leaves of this plant, which are hydrophobic and therefore repel water, and, secondly, to the nanostructure of the surface, which augments the repellent effect. Taking these nanostructural properties as a starting point, researchers have carried out a study in which they demonstrate the physical conditions required for the controlled production of drops between the micro- and nanoscales.

Water and oil may not mix, but, like two boxers nearing the end of the final round, they can get awfully tangled up. Now, scientists have created a filter that separates the two substances as quickly and cleanly as a ref breaking up a clinch. Their fine, stainless steel mesh is coated with carbon nanotubes about 10 microns across. They have a super-honeycomb structure that repels water,but they like organic stuff, like oil.
A scanning electron microscopy image of the carbon nanotube-coated filter
A scanning electron microscopy image of the carbon nanotube-coated filter. For comparison, the inset is bare stainless steel mesh.

Researchers advance toward hybrid spintronic computer chips. A team have created the first electronic circuit to merge traditional inorganic semiconductors with organic "spintronics" – devices that utilize the spin of electrons to read, write and manipulate data.

Friday, April 8, 2011

This week in nanotechnology - April 8, 2011

'Good cholesterol' nanoparticles seek and destroy cancer cells: Synthetic HDL nanoparticles loaded with small interfering RNA to silence cancer-promoting genes selectively shrunk or destroyed ovarian cancer tumors in mice, a research team led by scientists from The University of Texas MD Anderson Cancer Center and the University of North Texas Health Science Center reports.

Nanoparticles could offer big hope in a small package to the many millions of people who are allergic to the nickel in everything from jewelry to coins and cell phones, say scientists at Brigham and Women's Hospital. The scientists believe that nanoparticles containing calcium added to a cream or coated on a nickel-containing object could prevent the itchy redness associated with an allergy to the nickel found in everyday objects like rings.

With the first observation of thermoelectric effects at graphene contacts, University of Illinois researchers found that graphene transistors have a nanoscale cooling effect that reduces their temperature. Future computer chips made out of graphene – carbon sheets 1 atom thick – could be faster than silicon chips and operate at lower power.
An atomic force microscope tip scans the surface of a graphene-metal contact to measure temperature with spatial resolution of about 10 nm
An atomic force microscope tip scans the surface of a graphene-metal contact to measure temperature with spatial resolution of about 10 nm and temperature resolution of about 250 mK. Color represents temperature data.

Scientists at the Institute of Bioengineering and Nanotechnology (IBN) and IBM Research have developed the first biodegradable polymer nanoparticles to combat drug-resistant superbugs, such as Methicillin-Resistant Staphylococcus aureus (MRSA). These nanoparticles can selectively kill the bacteria without destroying healthy red blood cells, and being biodegradable, have great potential to treat infectious diseases in the body.

Using an advanced form of a rubber stamp, researchers have developed a way to adhere an ultra-thin antibacterial coating to a wound. The researchers describe a process for creating a transparent ultra-thin polymer coating carrying precise loads of extremely fine silver nanoparticles.

For the first time, the quantum behaviour of molecules consisting of more than 400 atoms was demonstrated by quantum physicists. The team sets a new record in the verification of the quantum properties of nanoparticles. In addition, an important aspect of the famous thought experiment known as 'Schroedinger's cat' is probed. However, due to the particular shape of the chosen molecules the reported experiment could be more fittingly called 'molecular octopus'.

Friday, April 1, 2011

This week in nanotechnology - April 1, 2011

How would you like to store all the films ever made on a device the size of an I-phone? Magnets made of just a few metallic atoms could make it possible to build radically smaller storage devices and have also recently been proposed as components for spintronics devices. There's just one obstacle on the way. Nano-sized magnets have only been seen to work at temperatures a few hairs above absolute zero. Now a chemistry student at the University of Copenhagen has demonstrated that molecular magnets using the metals ruthenium and osmium retain their magnetic properties at higher temperatures.

Scientists at Berkeley Lab's Molecular Foundry have pioneered a new chemical mapping method that provides unprecedented insight into materials at the nanoscale. Moving beyond traditional static imaging techniques, which provide a snapshot in time, these new maps will guide researchers in deciphering molecular chemistry and interactions at the nanoscale—critical for artificial photosynthesis, biofuels production and light-harvesting applications such as solar cells. This new technique allows the capture of very high-resolution images of nanomaterials with a huge amount of physical and chemical information at each pixel.
coaxial probe for imaging a carbon nanotube
Schematic of coaxial probe for imaging a carbon nanotube (left) and chemical map of carbon nanotube with chemical and topographical information at each pixel (right).

A Harvard bioengineer and an MIT aeronautical engineer have created a new device that can detect single cancer cells in a blood sample, potentially allowing doctors to quickly determine whether cancer has spread from its original site. The carbon nanotube-based microfluidic device is about the size of a dime, and could also detect viruses such as HIV. It could eventually be developed into low-cost tests for doctors to use in developing countries where expensive diagnostic equipment is hard to come by.

Stanford researchers have developed a battery that takes advantage of the difference in salinity between freshwater and seawater to produce electricity. As an indicator of the battery's potential for producing power, the research team calculated that if all the world's rivers were put to use, their batteries could supply about 2 terawatts of electricity annually – that's roughly 13 percent of the world's current energy consumption.

Researchers from North Carolina State University have investigated the viability of a technique called "spincasting" for creating thin films of nanoparticles on an underlying substrate – an important step in the creation of materials with a variety of uses, from optics to electronics. Spincasting, which utilizes centrifugal force to distribute a liquid onto a solid substrate, already has a variety of uses. For example, it is used in the electronics industry to deposit organic thin films on silicon wafers to create transistors.

Friday, March 25, 2011

This week in nanotechnology - March 25, 2011

Researchers at the University of Illinois have developed a three-dimensional nanostructure for battery cathodes that allows for dramatically faster charging and discharging without sacrificing energy storage capacity. This system gives you capacitor-like power with battery-like energy.

Researchers at Rice University have created a synthetic material that gets stronger from repeated stress much like the body strengthens bones and muscles after repeated workouts. The trick, it seems, lies in the complex, dynamic interface between nanostructures and polymers in carefully engineered nanocomposite materials.

Graphene study raises question: Is space like a chessboard? Physicists at UCLA set out to design a better transistor and ended up discovering a new way to think about the structure of space. Space is usually considered infinitely divisible — given any two positions, there is always a position halfway between. But in a recent study aimed at developing ultra-fast transistors using graphene, researchers from the UCLA Department of Physics and Astronomy and the California NanoSystems Institute show that dividing space into discrete locations, like a chessboard, may explain how point-like electrons, which have no finite radius, manage to carry their intrinsic angular momentum, or "spin.
spinning electrons
The standard cartoon of an electron shows a spinning sphere with positive or negative angular momentum, as illustrated in blue or gold above. However, such cartoons are fundamentally misleading: compelling experimental evidence indicates that electrons are ideal point particles, with no finite radius or internal structure that could possibly "spin".

Like copper wires in our everyday life, nanowires are envisioned to act as interconnecting elements in future electronic circuits on the nanoscale. Moreover, when made from semiconductors these nanowires not only transport electric current along their axis but also can very efficiently emit light. Researchers in Munich have found a way to combine these two fundamental properties.

Princeton researchers have invented an extremely sensitive sensor that opens up new ways to detect a wide range of substances, from tell-tale signs of cancer to hidden explosives. The sensor, which is the most sensitive of its kind to date, relies on a completely new architecture and fabrication technique. The device boosts faint signals generated by the scattering of laser light from a material placed on it, allowing the identification of various substances based on the color of light they reflect. The sample could be as small as a single molecule.

Friday, March 18, 2011

This week in nanotechnology - March 18, 2011

Conventional approaches to desalination are thermal distillation and reverse osmosis. A faster, better and cheaper desalination process enhanced by carbon nanotubes has been developed. The process creates a unique new architecture for the membrane distillation process by immobilizing carbon nanotubes in the membrane pores.

Scientists achieve breakthrough in nanocomposite for high-capacity hydrogen storage. Researchers have designed a new composite material for hydrogen storage consisting of nanoparticles of magnesium metal sprinkled through a matrix of polymethyl methacrylate, a polymer related to Plexiglas. This pliable nanocomposite rapidly absorbs and releases hydrogen at modest temperatures without oxidizing the metal after cycling—a major breakthrough in materials design for hydrogen storage, batteries and fuel cells.

A quantum pen for single atoms: Physicists succeeded in manipulating atoms individually in a lattice of light and in arranging them in arbitrary patterns. These results are an important step towards large scale quantum computing and for the simulation of condensed matter systems.
The atomic patterns each consist of 10 - 30 single atoms that are kept in an artificial crystal of light
With the addressing scheme arbitrary patterns of atoms in the lattice can be prepared. The atomic patterns each consist of 10 - 30 single atoms that are kept in an artificial crystal of light.

A 328 nanometer, 276 picosecond step for spintronics. Researchers built spintronic transistors and used them to align the magnetic "spins" of electrons for a record period of time in silicon chips at room temperature. The study is a step toward computers, phones and other spintronic devices that are faster and use less energy than their electronic counterparts. During the new study, the electrons retained their spins for 276 picoseconds, or 276 trillionths of a second. And based on that lifetime, the researchers calculate the spin-aligned electrons moved through the silicon 328 nanometers.

Researchers have learned to control the quantum pathways determining how light scatters in graphene. Controlled scattering provides a new tool for the study of this unique material and may point to practical applications for controlling light and electronic states in graphene nanodevices.

Scientists have developed a revolutionary way to control the growth, and provide additional functionality, to a family of smart materials known as metal-organic frameworks, or MOFs. The new technique, known as seeding, which allows the user to have complete control over where and how the MOF crystals grow. Additionally the seeding technique greatly speeds up the growth process.

Friday, March 11, 2011

This week in nanotechnology, March 11, 2011

Nanomaterial technology would dramatically extend battery life for mobile devices. Technophiles who have been dreaming of mobile devices that run longer on lighter, slimmer batteries may soon find their wish has been granted. University of Illinois engineers have developed a form of ultra-low-power digital memory that is faster and uses 100 times less energy than similar available memory. The technology could give future portable devices much longer battery life between charges.

Precision measurement in the world of nanoparticles has now become a possibility, thanks to scientists at UC Santa Barbara. The UCSB research team has developed a new instrument capable of detecting individual nanoparticles with diameters as small as a few tens of nanometers. This device opens up a wide range of potential applications in nanoparticle analysis.

Ultra fast photodetectors out of carbon nanotubes: Carbon nanotubes have a multitude of unusual properties which make them promising candidates for optoelectronic components. However, so far it has proven extremely difficult to analyze or influence their optic and electronic properties. A team of researchers has now succeeded in developing a measurement method allowing a time-based resolution of the so-called photocurrent in photodetectors with picosecond precision.
Scanning tunneling microscopy  of organic molecules
Single-walled carbon nanotubes are promising building blocks for future optoelectronic devices. With this measurement set-up physicists can resolve the ultra fast optoelectronic dynamics of carbon-nanotubes. A first laser exites electrons in the carbon-nanotubes spanning the gap between two gold electrodes while a second laser measures the resulting photo-current.

Circulating tumor cells, which play a crucial role in cancer metastasis, have been known to science for more than 100 years, and researchers have long endeavored to track and capture them. Now, a UCLA research team has developed an innovative device based on Velcro-like nanoscale technology to efficiently identify and "grab" these circulating tumor cells, or CTCs, in the blood.

Graphene oxide has had a scrum of researchers fall upon it as it retains much of the properties of the highly valued super material pure graphene, but it is much easier, and cheaper, to make in bulk quantities; easier to process; and its significant oxygen content appears to make it soluble in water. However new research led by University of Warwick researchers has found that that last assumption is incorrect and unfortunately graphene oxide's solubility literally comes out in the wash.

New molecular robot can be programmed to follow instructions. Scientists have developed a programmable "molecular robot" — a sub-microscopic molecular machine made of synthetic DNA that moves between track locations separated by 6 nm. The robot, a short strand of DNA, follows instructions programmed into a set of fuel molecules determining its destination, for example, to turn left or right at a junction in the track.

Friday, March 4, 2011

This week in nanotechnology - March 4, 2011

Diamond may have a softer side: T-carbon. This fluffy form of diamond, simulated in a Chinese supercomputer, could be used for a variety of applications — if someone can make the stuff and prove its stability in the real world.

The study of the physical properties and potential applications of graphene has suffered from a lack of suitable carrier materials that can support a flat graphene layer while not interfering with its electrical properties. Researchers in the University of Arizona's physics department along with collaborators from the Massachusetts Institute of Technology and the National Materials Science Institute in Japan have now taken an important step forward toward overcoming those obstacles. They found that placing graphene on boron nitride improves its electronic properties.

By mimicking the structure of the silk moth's antenna, University of Michigan researchers led the development of a better nanopore – a tiny tunnel-shaped tool that could advance understanding of a class of neurodegenerative diseases that includes Alzheimer's. The team engineered an oily coating that traps and smoothly transports molecules of interest through nanopores. The coating also allows researchers to adjust the size of the pore with close-to-atomic precision.
Scanning tunneling microscopy  of organic molecules
A new oily coating that improves the functionality of nanopores was inspired by a similar layer in the silk moth's antenna. Nanopores are measurement devices that enable the study of single molecules or proteins.

A spongy substance that could be mistaken for packing material has the nanotechnology world buzzing. University of Central Florida Associate Professor Lei Zhai and postdoctoral associate Jianhua Zou have engineered carbon nanotube aerogel in such a way that it could be used to detect pollutants and toxic substances, improve robotic surgery techniques and store energy more efficiently.

Supercomputers the size of sugar cubes - within the next 10 years, IBM scientists and developers aim to build computers featuring exascale computing performance, but with an absolute energy consumption that is not much higher than that of today's largest systems. Exascale computers are capable of reaching a performance of one ExaFLOP/s, which corresponds to 1018 floating point operations per second. This is about 300 times faster than today's fastest supercomputer.

They are corrosion resistant, mechanically strong and withstand exceedingly high temperatures. With such characteristics, porous metals are generating a growing interest in numerous innovative fields of technology. They are characterised by nanostructured surfaces with pores measuring only a few nanometres in diameter. An international research team including has successfully developed a heavy-duty and cost-efficient ultrasound procedure for the design and production of such metallic structures.

Friday, February 25, 2011

This week in nanotechnology - February 25, 2011

For the first time, scientists have managed to measure the atomic structure of individual nanoparticles. The experimental data could help better understand the properties of nanoparticles in future. The exact 3D morphology, atomic structure and especially the surface composition of nanoparticles govern their chemical and physical properties. In a study, the three-dimensional structure of individual nanoparticles has now successfully been determined on the atomic level.

New nanomaterials research from the University at Buffalo could lead to new solutions for an age-old public health problem: how to separate bacteria from drinking water. Working with a special kind of polymer called a block copolymer, a research team has synthesized a new kind of nanomembrane containing pores about 55 nanometers in diameter -- large enough for water to slip through easily, but too small for bacteria.

For the first time, a team of scientists have succeeded in combining the concepts of spin electronics and molecular electronics in a single component consisting of a single molecule. Components based on this principle have a special potential, as they allow for the production of very small and highly efficient magnetic field sensors for read heads in hard disks or for non-volatile memories in order to further increase reading speed and data density.
Scanning tunneling microscopy  of organic molecules
Scanning tunneling microscopy (50 x 50 nm2) of organic molecules. Coloring indicates variable spin orientation.

MIT engineers have designed a new type of nanoparticle that could safely and effectively deliver vaccines for diseases such as HIV and malaria. The new particles consist of concentric fatty spheres that can carry synthetic versions of proteins normally produced by viruses. These synthetic particles elicit a strong immune response — comparable to that produced by live virus vaccines — but should be much safer.

Researchers have developed a simple method of making short protein chains with spiral structures that can also dissolve in water, two desirable traits not often found together. Such structures could have applications as building blocks for self-assembling nanostructures and as agents for drug and gene delivery.

Vaccine scientists say their "Holy Grail" is to stimulate immunity that lasts for a lifetime. Live viral vaccines such as the smallpox or yellow fever vaccines provide immune protection that lasts several decades, but despite their success, scientists have remained in the dark as to how they induce such long lasting immunity. Scientists now have designed nanoparticles that resemble viruses in size and immunological composition and that induce lifelong immunity in mice. They designed the particles to mimic the immune-stimulating effects of one of the most successful vaccines ever developed – the yellow fever vaccine. The particles, made of biodegradable polymers, have components that activate two different parts of the innate immune system and can be used interchangeablywith material from many different bacteria or viruses.

Friday, February 18, 2011

This week in nanotechnology - February 18, 2011

Researchers have documented the first observations of some unusual physics when two prominent electric materials are connected: superconductors and graphene. When a current is applied to a normal conductor, such as metal or graphene, it flows through the material as a stream of single electrons. By contrast, electrons travel in pairs in superconductors. Yet when a normal material is sandwiched between superconductors, the normal metal can carry the supercurrent.

From the art world: Nanoscopic investigation shows why van Gogh paintings lose their shine. cientists have identified a complex chemical reaction responsible for the degradation of two paintings by Vincent van Gogh and other artists of the late 19th century. This discovery is a first step to understanding how to stop the bright yellow colours of van Gogh's most famous paintings from being covered by a brown shade, and fading over time. In the meantime, the results suggest shielding affected paintings as much as possible from UV and sunlight.
how X-Rays were used to study why van Gogh paintings lose their shine
This illustration shows how X-Rays were used to study why van Gogh paintings lose their shine. Top: a photo of the painting "Bank of the River Seine" on display at the van Gogh Museum, divided in three and artificially colored to simulate a possible state in 1887 and 2050. Bottom left: microscopic samples from art masterpieces moulded in plexiglass blocks. The tube with yellow chrome paint is from the personal collection of M. Cotte. Bottom right: X-ray microscope set-up at the ESRF with a sample block ready for a scan. Centre: an image made using a high-resolution, analytical electron microscope to show affected pigment grains from the van Gogh painting, and how the color at their surface has changed due to reduction of chromium.

Scientists have invented a new way of creating atom thin nano-sheets from a wide variety of exotic layered materials with the potential to enable the next generation of electronic and energy storage technologies needed, for example, to power electric cars.

Engineering atomic interfaces for new electronics: A multi-institutional team has made fundamental discoveries at the border regions, called interfaces, between oxide materials. The team has discovered how to manipulate electrons oxide interfaces by inserting a single layer of atoms. The researchers also have discovered unusual electron behaviors at these engineered interfaces.

And finally, some Friday fun: Geckoman! Video game introduces youths to big ideas about a nano-sized world. Working on a science fair project with his lab partner Nikki, Harold Biggums finds himself transformed into a tiny superhero and flung into the midst of an alien plot to take over the world — a plot that he and Nikki can foil only by defying gravity, walking on water and charging across electric fields. This narrative dilemma is the basic storyline for Geckoman! - A video game about nanoscale forces, an online video game developed by Northeastern University researchers at the Center for High-rate Nanomanufacturing (CHN), which seeks to educate middle-school students about nanoscience and technology.

Friday, February 11, 2011

This week in nanotechnology - February 11, 2011

Engineers and scientists collaborating at Harvard University and the MITRE Corporation have developed and demonstrated the world's first programmable nanoprocessor. The groundbreaking prototype computer system represents a significant step forward in the complexity of computer circuits that can be assembled from synthesized nanometer-scale components.

In a complex feat of nanoengineering, a team of scientists at Kyoto University and the University of Oxford have succeeded in creating a programable molecular transport system, the workings of which can be observed in real time. The results open the door to the development of advanced drug delivery methods and molecular manufacturing systems.

Engineers at the University of California, Berkeley, have found a way to grow nanolasers directly onto a silicon surface, an achievement that could lead to a new class of faster, more efficient microprocessors, as well as to powerful biochemical sensors that use optoelectronic chips. Ultimately, this technique may provide a powerful and new avenue for engineering on-chip nanophotonic devices such as lasers, photodetectors, modulators and solar cells.

It has been a dream of researchers for over a decade: image biological materials at high resolution using incredibly intense X-ray laser pulses. Calculations had long predicted that these blasts of X-rays would allow exquisite measurements of the molecular structure of biological objects, from samples too small to be studied by conventional methods. Now, an international collaboration has proven this principle at the Linac Coherent Light Source (at SLAC National Accelerator Laboratory in California, USA) by forming images of the Photosystem I protein complex and particles of the Mimivirus. The results open a way for obtaining the molecular structures of proteins and viruses without the requirement of high-quality crystals.
Three-dimensional rendering of X-ray diffraction data obtained from over 15 000 single nanocrystal diffraction snapshots
Three-dimensional rendering of X-ray diffraction data obtained from over 15 000 single nanocrystal diffraction snapshots.

Researchers from from Nagoya University in Japan and Aalto University in Finland along with their colleagues have developed a simple and fast process to manufacture high quality carbon nanotube-based thin film transistors on a plastic substrate. They used this technology to manufacture the world's first sequential logic circuits using carbon nanotubes. Using this technology, we can expect the development of high-speed roll-to-roll manufacturing processes to manufacture low cost flexible devices such as electronic paper in the future.

A new combination of nanoparticles and graphene results in a more durable catalytic material for fuel cells. The catalytic material is not only hardier but more chemically active as well. The researchers are confident the results will help improve fuel cell design. The unique structure of this material provides much needed stability, good electrical conductivity and other desired properties.

Friday, February 4, 2011

This week in nanotechnology - February 4, 2011

Windshields that shed water so effectively that they don't need wipers. Ship hulls so slippery that they glide through the water more efficiently than ordinary hulls. These are some of the potential applications for graphene, one of the hottest new materials in the field of nanotechnology. Researchers have now figured out how to create a freestanding film of graphene oxide and alter its surface roughness so that it either causes water to bead up and run off or causes it to spread out in a thin layer.

Researchers from the University of Alabama at Birmingham's School of Engineering have created a three-dimensional electrospun scaffold on the nanoscale that more effectively and efficiently facilitates cell and tissue growth in the laboratory.

Using a concept called DNA origami, Arizona State University researchers are trying to pave the way to produce the next generations of electronics products. They have discovered a way to use DNA to effectively combine top-down lithography with chemical bonding involving bottom-up self-assembly. Enabling various molecules to attach to the DNA produces smaller nanostructure configurations – thus opening the way to construction of smaller electronic device components.
DNA origami nanotubes
DNA origami nanotubes can be efficiently aligned between gold islands with various interisland distances and relative locations. This development represents progress toward the goal of bridging bottom-up and top-down assembly approaches.

A new type of thin solar cell based on a honeycomb pattern of nanoscale dimples could offer a new direction for the field. Researchers at Stanford University succeeded in harnessing plasmonics to more effectively trap light within thin solar cells to improve performance and push them one step closer to daily reality.

University of Maryland researchers have made a breakthrough in the use of visible light for making tiny integrated circuits. They introduced a technique called RAPID lithography that makes it possible to use visible light to attain lithographic resolution comparable to (and potentially even better than) that obtained with shorter wave length radiation. Though their advance is probably at least a decade from commercial use, they say it could one day make it possible for companies like Intel to continue their decades long tread of making ever smaller, faster, and cheaper computer chips.

For almost two decades, cardiologists have searched for ways to see dangerous blood clots before they cause heart attacks. Now, researchers at Washington University School of Medicine in St. Louis report that they have designed nanoparticles that find clots and make them visible to a new kind of X-ray technology. These nanoparticles will take the guesswork out of deciding whether a person coming to the hospital with chest pain is actually having a heart attack.

Friday, January 28, 2011

This week in nanotechnology - January 28, 2011

Van der Waals forces are fundamental for chemistry, biology and physics. However, they are among the weakest known chemical interactions, so they are notoriously hard to study. This force is so weak that it is hard to notice in everyday life. But delve into the world of micro-machines and nano-robots, and you will feel the force – everywhere. To study the van-der-Waals force, researchers have designed a sophisticated experimental setup that can measure the interactions between single atoms and a surface.

Researchers developed a molecular machine constructed in a similar way to a record player. The team has succeeded for the first time in directly controlling the magnetic state of a single molecule at room temperature. The switchable molecule could be used both in the construction of tiny electromagnetic storage units and in the medical imaging.

Curved carbon for electronics of the future. A new scientific discovery could have profound implications for nanoelectronic components. Researchers from the Nano-Science Center at the Niels Bohr Institute, University of Copenhagen, in collaboration with Japanese researchers, have shown how electrons on thin tubes of graphite exhibit a unique interaction between their motion and their attached magnetic field – the so-called spin. The discovery paves the way for unprecedented control over the spin of electrons and may have a big impact on applications for spin-based nanoelectronics.

Despite the sophistication and range of contemporary microscopy techniques, many important biological phenomena still elude the precision of even the most sensitive tools. The need for refined imaging methods for fundamental research and biomedical applications related to the study of disease remains acute. Researchers at the Biodesign Institute at Arizona State University have pioneered a new technique capable of peering into single cells and even intracellular processes with unprecedented clarity. The method, known as electrochemical impedance microscopy (EIM) may be used to explore subtle features of profound importance for basic and applied research, including cell adhesion, cell death (or apoptosis) and electroporation—a process that can be used to introduce DNA or drugs into cells.

Researchers from Boston College, MIT, Clemson University and the University of Virginia have used nanotechnology to achieve a 60-90 percent increase in the thermoelectric figure of merit of p-type half-Heusler, a common bulk semiconductor compound. The dramatic increase in the figure of merit, used to measure a material's relative thermoelectric performance, could pave the way for a new generation of products – from car exhaust systems and power plants to solar power technology – that runs cleaner.

Northwestern University researchers have developed a new technique for rapidly prototyping nanoscale devices and structures that is so inexpensive the "print head" can be thrown away when done.
Hard-tip, soft-spring lithography (HSL) rolls into one method the best of scanning-probe lithography -- high resolution -- and the best of polymer pen lithography -- low cost and easy implementation.

And finally, some Friday fun. Take a look at some of the winning images from a recent nano-image competition, like this 'stem of nanoflowers'.

Friday, January 21, 2011

This week in nanotechnology - January 21, 2011

To rebuild damaged parts of a human body from scratch is a dream that has long fired human imagination, from Mary Shelley's Doctor Frankenstein to modern day surgeons. Now, a team of European scientists, working in the frame of the EUREKA project ModPolEUV, has made a promising contribution to reconstructive surgery thanks to an original multidisciplinary approach matching cutting-edge medicine to the latest developments in nanotechnology. They managed to develop a new and simple way to create nanostructured materials that would allow a better development of human cells.

Measuring the attractive forces between atoms and surfaces with unprecedented precision, University of Arizona physicists have produced data that could refine our understanding of the structure of atoms and improve nanotechnology. To study the van-der-Waals force,the team designed a sophisticated experimental setup that can measure the interactions between single atoms and a surface.

Scientists have coaxed polymers to braid themselves into wispy nanoscale ropes that approach the structural complexity of biological materials. Their work is the latest development in the push to develop self-assembling nanoscale materials that mimic the intricacy and functionality of nature's handiwork, but which are rugged enough to withstand harsh conditions such as heat and dryness.

A nanoscale rope that braids itself, as seen in this atomic force microscopy image of the structure at a resolution of one-millionth of a meter.

Researchers at Northwestern University have placed nanocrystals of rock salt into lead telluride, creating a material that can harness electricity from heat-generating items such as vehicle exhaust systems, industrial processes and equipment and sun light more efficiently than scientists have seen in the past. The material exhibits a high thermoelectric figure of merit that is expected to enable 14 percent of heat waste to electricity, a scientific first.

Butterfly wings behind anti-counterfeiting nanotechnology: Researchers are using nanoholes to create unique anti-counterfeiting security features. How this works is microscopic gratings composed of nanostructures interact with light to produce the shimmering iridescence seen on the Costa Rican morpho butterfly. The nanostructures act to reflect and refract light waves to produce the morpho's signature blue wings and absorb other unwanted light.

In solar cells and photodetectors, an optical radiation excites electrons to higher energy states, thereby a photocurrent begins to flow. Scientists have now found a way to directly measure the time during which photo-excited electrons flow in nanoscale photodetectors.

University of Illinois materials scientists have developed a simple, generalizable technique to fabricate complex structures that assemble themselves. Their advance utilizes a new class of self-assembling materials that they developed. The team demonstrated that they can produce a large, complex structure – an intricate lattice – from tiny colloidal particles called triblock Janus spheres.

Friday, January 14, 2011

This week in nanotechnology - January 14, 2011

A team of scientists has created very soft hydrogel particles that closely mirror some of the key properties of red blood cells, potentially helping pave the way for the development of synthetic blood. Tests of the particles' ability to perform functions such as transporting oxygen or carrying therapeutic drugs have not been conducted, and they do not remain in the cardiovascular system as long as real red blood cells.

New research shows how light can be used to control the electrical properties of graphene, paving the way for graphene-based optoelectronic devices and highly sensitive sensors.

A few unassuming drops of liquid locked in a very precise game of "follow the leader" could one day be found in mobile phone cameras, medical imaging equipment, implantable drug delivery devices, and even implantable eye lenses. Engineering researchers have developed liquid pistons, in which oscillating droplets of ferrofluid precisely displace a surrounding liquid. The pulsating motion of the ferrofluid droplets, which are saturated with metal nanoparticles, can be used to pump small volumes of liquid. The study also demonstrated how droplets can function as liquid lenses that constantly move, bringing objects into and out of focus.

European researchers report direct observation of carbon monoxide binding. Carbon monoxide is highly toxic since it blocks the binding site for oxygen in hemoglobin. This very principle – a porphyrin ring with a central iron or cobalt atom that the poisonous gas attaches to – can be used to implement sensors to warn against carbon monoxide. Physicists have now deciphered the mechanism for binding of gas molecules to iron and cobalt porphyrins.

A scanning tunneling microscopy image (left) shows four porphyrins. The models (right) illustrate the two systems shown in the picture. The protrusions correspond to the central atom (yellow sphere) and the two elevated portions to the saddle (orange). The characteristic cross shape results from the attached carbon monoxide molecules (red and blue).

Many futurists envision a world in which polymer membranes with molecular-sized channels are used to capture carbon, produce solar-based fuels, or desalinate sea water, among many other functions. This will require methods by which such membranes can be readily fabricated in bulk quantities. A technique representing a significant first step down that road has now been successfully demonstrated.

Researchers have created the first coils of silicon nanowire on a substrate that can be stretched to more than double their original length, moving us closer to incorporating stretchable electronic devices into clothing, implantable health-monitoring devices, and a host of other applications.

Fastest movie in the world recorded - a method to film nanostructures. Processes at a molecular level are not only miniscule, they are often extremely fast, and therefore difficult to capture in action. Scientists now present a method that takes us a good step towards producing a "molecular movie". They can record two pictures at such a short time interval that it will soon be possible to observe molecules and nanostructures in real time.

Researchers have demonstrated bio-inspired structures that self-assemble from simple building blocks: spheres. The helical "supermolecules" are made of tiny colloid balls instead of atoms or molecules. Similar methods could be used to make new materials with the functionality of complex colloidal molecules.

Friday, January 7, 2011

This week in nanotechnology - January 7, 2011

An entirely new type of nanomaterial developed at Rensselaer Polytechnic Institute could enable the next generation of high-power rechargeable lithium (Li)-ion batteries for electric automobiles, as well as batteries for laptop computers, mobile phones, and other portable devices. The new material, dubbed a "nanoscoop" because its shape resembles a cone with a scoop of ice cream on top, can withstand extremely high rates of charge and discharge that would cause conventional electrodes used in today's Li-ion batteries to rapidly deteriorate and fail. The nanoscoop's success lies in its unique material composition, structure, and size.

A quick look at new Cornell research hints at colorful patchwork quilts, but they are actually pictures of graphene -- one atom-thick sheets of carbon stitched together at tilted interfaces. Researchers have unveiled striking, atomic-resolution details of what graphene "quilts" look like at the boundaries between patches, and have uncovered key insights into graphene's electrical and mechanical properties.
A false-color microscopy image overlay depicting the shapes and lattice orientations of several grains in graphene

A false-color microscopy image overlay depicting the shapes and lattice orientations of several grains in graphene.

Researchers are creating a new type of solar cell designed to self-repair like natural photosynthetic systems in plants by using carbon nanotubes and DNA, an approach aimed at increasing service life and reducing cost. The design exploits the unusual electrical properties of single-wall carbon nanotubes, using them as molecular wires in light harvesting cells.

A promising approach for making solar cells that are inexpensive, lightweight and flexible is to use organic (that is, carbon-containing) compounds instead of expensive, highly purified silicon. But one stubborn problem has slowed the development of such cells: Researchers have had a hard time coming up with appropriate materials for the electrodes to carry the current to and from the cells. Now, a team of MIT researchers has come up with a practical way of using a possible substitute made from graphene.

Nanotechnologists at the University of Texas at Dallas have invented a broadly deployable technology for producing weavable, knittable, sewable, and knottable yarns containing up to 95 weight percent of otherwise unspinnable guest powders and nanofibers. The researchers describe the use of biscrolling to solve these problems, and demonstrate the feasibility of using their biscrolled yarns for applications ranging from superconducting cables and electronic textiles to batteries and fuel cells containing flexible woven electrodes.