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In this reconstruction by Matthew Landry, nanoparticles (blue spheres) travel through a nanochannel (red) similar in dimensions to what will be used in the space-bound experiments. (Image credit: Methodist Hospital Research Institute)

A microgravity experiment designed at The Methodist Hospital Research Institute will be funded by The Center for the Advancement of Science in Space (CASIS) to fly aboard the International Space Station U.S. National Laboratory. The proposal to study the diffusion of drug-like particles will receive about $200,000 from CASIS, which is directed by Congress to manage, promote, and broker research for the orbiting U.S. National Laboratory. If all goes well on Earth, the experiment will go to the International Space Station as early as 2014. Principal investigator Alessandro Grattoni, Ph.D., and a team of scientists from Methodist, BioServe Space Technologies at the University of Colorado at Boulder, and NASA Glenn Research Center in Cleveland, Ohio, will study the movement of drug-like particles through tiny channels. The scientists' ultimate goal is improving implantable devices that release pharmaceutical drugs at a steady rate. Nearly all drugs taken orally spike in concentration, decay quickly, and are only at their peak effectiveness for a short period of time. Grattoni and co-PI Mauro Ferrari, Ph.D., have been working on a solution -- nanocapsules implanted beneath the skin that release pharmaceutical drugs through a nanochannel membrane and into the body at a sustained, steady rate. To design better nanochannels for a given drug, Grattoni says he and others need to improve their understanding of the underlying physics. Grattoni's group will look at two things they believe play a major role in how particles move through channels -- the relative size of particle to channel, as well as charge (plus/minus) interactions between the particle and channel. The fluorescent silicon particles will diffuse into an empty chamber through a long series of narrow channels. Photographs taken periodically with a fluorescent microscope will show the scientists how -- and how quickly -- the particles move, how charge gradients affect the particles, and the effects of size constraints. The experiment will be performed over three months.

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Electron pumps made from graphene work ten times faster than similar pumps made from conventional three-dimensional materials and can be used to generate larger currents. (Image credit: Malcolm Connolly, NPL/Cambridge)

A new joint innovation by the National Physical Laboratory (NPL) and the University of Cambridge could pave the way for redefining the ampere in terms of fundamental constants of physics. The world's first graphene single-electron pump (SEP) provides the speed of electron flow needed to create a new standard for electrical current based on electron charge. A good SEP pumps precisely one electron at a time to ensure accuracy, and pumps them quickly to generate a sufficiently large current. Up to now the development of a practical electron pump has been a two-horse race. Tuneable barrier pumps use traditional semiconductors and have the advantage of speed, while the hybrid turnstile utilises superconductivity and has the advantage that many can be put in parallel. Traditional metallic pumps, thought to be not worth pursuing, have been given a new lease of life by fabricating them out of the world's most famous super-material - graphene. Previous metallic SEPs made of aluminium are very accurate, but pump electrons too slowly for making a practical current standard. Graphene's unique semi-metallic two-dimensional structure has just the right properties to let electrons on and off the quantum dot very quickly, creating a fast enough electron flow - at near gigahertz frequency - to create a current standard. The Achilles' heel of metallic pumps, slow pumping speed, has thus been overcome by exploiting the unique properties of graphene.

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Rice University’s latest nanotechnology breakthrough was more than 10 years in the making, but it still came with a shock. Scientists from Rice, the Dutch firm Teijin Aramid, the U.S. Air Force and Israel’s Technion Institute recently unveiled a new carbon nanotube (CNT) fiber that looks and acts like textile thread and conducts electricity and heat like a metal wire. In this week’s issue of Science, the researchers describe an industrially scalable process for making the threadlike fibers, which outperform commercially available high-performance materials in a number of ways. “We finally have a nanotube fiber with properties that don’t exist in any other material,” said lead researcher Matteo Pasquali, professor of chemical and biomolecular engineering and chemistry at Rice. “It looks like black cotton thread but behaves like both metal wires and strong carbon fibers.” The research team includes academic, government and industrial scientists from Rice; Teijin Aramid’s headquarters in Arnhem, the Netherlands; the Technion-Israel Institute of Technology in Haifa, Israel; and the Air Force Research Laboratory (AFRL) in Dayton, Ohio. “The new CNT fibers have a thermal conductivity approaching that of the best graphite fibers but with 10 times greater electrical conductivity,” said study co-author Marcin Otto, business development manager at Teijin Aramid. “Graphite fibers are also brittle, while the new CNT fibers are as flexible and tough as a textile thread. We expect this combination of properties will lead to new products with unique capabilities for the aerospace, automotive, medical and smart-clothing markets.”    

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A centre for research on graphene, a material which has the potential to revolutionise numerous industries, ranging from healthcare to electronics, is to be created at the University of Cambridge. The University has been a hub for graphene engineering from the very start and now aims to make this “wonder material” work in real-life applications. The Cambridge Graphene Centre will start its activities on February 1st 2013, with a dedicated facility due to open at the end of the year. Its objective is to take graphene to the next level, bridging the gap between academia and industry. It will also be a shared research facility with state-of-the-art equipment, which any scientist researching graphene will have the opportunity to use. The Centre’s activities will be funded by a Government grant worth more than £12 million, which was allocated to the University in December by the Engineering and Physical Sciences Research Council (EPSRC). The rest of this money will support projects focusing both on how to manufacture high-quality graphene on an industrial scale, and on developing some of its potential applications.

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A recent NIST patent shows that nanopores, which may one day help doctors perform quick analysis of blood samples, are not harmed by the polymerization process that could help nanopores operate in biochips. Polymerization hardens and stabilizes the membrane surrounding the nanopores, both of which are beneficial effects. Image Credit: Robertson/NIST

Having blood drawn and analyzed to diagnose disease is a process that can take a few days, but what if your doctor could perform this analysis in moments, right before your eyes? That’s the promise of “lab on a chip” technology, and researchers are working on a variety of fronts to remove technical roadblocks. A new idea recently patented by the National Institute of Standards and Technology (NIST) and the Naval Research Laboratory (NRL) addresses the issue of sensor shelf life, showing how some such chips might be made to last for months or more until needed. NIST’s John Kasianowicz has spent decades trying to create technologies that will enable doctors to perform fast, real-time chemical analysis, and one promising approach involves building arrays of tiny pores, each small enough that only one protein or DNA molecule at a time can pass through and be identified. As our bodies respond to infection or other disease states, our cells release different proteins, and measuring the concentrations of these chemicals in a blood sample can provide a quick snapshot of our health. A membrane peppered with large numbers of these “nanopores” might give doctors a way to take that snapshot easily, if it could be mounted on a biochip compatible with electronics and computer technologies. The teams explored the possibility of turning the lipids into polymers, the sorts of molecular chains used in plastics. Polymerizing the lipids made them tougher, but the question was whether doing so would somehow render the nanopores ineffective at trapping and identifying the blood serum proteins, because the process either squeezes or stretches the tiny membrane holes dramatically. Tests at NIST showed the nanopores performed just as well as before, meaning polymerized membranes could work on a biochip.

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ASSIST Center Director Dr. Veena Misra (center left) and Deputy Director Dr. John Muth (center right) are pictured in the Nanostructures Laboratory at North Carolina State University. The ASSIST Center, an NSF Nanosystems Engineering Research Center (NERC) begun in 2012, brings together researchers at NCSU and partner institutions to create self-powered devices that help people monitor their health and understand how it is affected by their environment.(Image Credit: Marc Hall, North Carolina State University)

The U.S. National Science Foundation (NSF) recently awarded $55.5 million to university consortia to establish three new Engineering Research Centers (ERCs) that will advance interdisciplinary nanosystems research and education in partnership with industry. Over the next five years, these Nanosystems ERCs, or NERCS, will advance knowledge and create innovations that address significant societal issues, such as the human health and environmental implications of nanotechnology. At the same time, they will advance the competitiveness of U.S. industry. The centers will support research and innovation in electromagnetic systems, mobile computing and energy technologies, nanomanufacturing, and health and environmental sensing.

  • The NSF Nanosytems Engineering Research Center for Advanced Self-Powered Systems of Integrated Sensors and Technology (ASSIST), led by North Carolina State University, will create self-powered wearable systems that simultaneously monitor a person's environment and health, in search of connections between exposure to pollutants and chronic diseases.
  • The NSF Nanosystems Engineering Research Center for Nanomanufacturing Systems for Mobile Computing and Mobile Energy Technologies (NASCENT), led by the University of Texas at Austin, will pursue high-throughput, reliable, and versatile nanomanufacturing process systems, and will demonstrate them through the manufacture of mobile nanodevices.
  • The NSF Nanosystems Engineering Research Center for Translational Applications of Nanoscale Multiferroic Systems (TANMS), led by the University of California Los Angeles, will seek to reduce the size and increase the efficiency of components and systems whose functions rely on the manipulation of either magnetic or electromagnetic fields.
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The robots, just half a millimeter wide, are composed of microparticles. Confined between two liquids, they assemble themselves into star shapes when an alternating magnetic field is applied. (Credit: Argonne National Lab)

Alexey Snezhko and Igor Aronson, physicists at the U.S. Department of Energy's (DOE) Argonne National Laboratory, have coaxed "micro-robots" to do their bidding. The robots, just half a millimeter wide, are composed of microparticles. Confined between two liquids, they assemble themselves into star shapes when an alternating magnetic field is applied. Snezhko and Aronson can control the robots' movement and even make them pick up, transport and put down other non-magnetic particles—potentially enabling fabrication of precisely designed functional materials in ways not currently possible. Snezhko and Aronson suspended the tiny ferromagnetic particles between two layers of immiscible, or non-mixing, fluids. Without a magnetic field, the particles drift aimlessly or clamp together. But when an alternating magnetic field is applied perpendicular to the liquid surface, they self-assemble into spiky circular shapes that the scientists nicknamed "asters", after the flower. Left to their own devices, the asters don't swim. "But if you apply a second small magnetic field parallel to the surface, they begin to move," said Aronson. "The field breaks the symmetry of the asters' hydrodynamic flow, and the asters begin to swim." By changing the magnetic field, the researchers discovered they could remotely control the asters' motion. "We can make them open their jaws and close them," said Snezhko. "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 research is a part of the ongoing effort, funded by the DOE, to understand and design active self-assembled materials. These structures can assemble, disassemble, and reassemble autonomously or on command and will enable novel materials capable of multi-tasking and self-repair.
 httpvh://www.youtube.com/watch?v=zCGilxUtVr0

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Collage of NIST "nano-eggs" — simulated magnetic patterns in NIST’s egg-shaped nanoscale magnets.Image Credit: Talbott/NIST

Magnetics researchers at the U.S. National Institute of Standards and Technology (NIST) colored lots of eggs recently. Bunnies and children might find the eggs a bit small — in fact, too small to see without a microscope. But these "eggcentric" nanomagnets have another practical use, suggesting strategies for making future low-power computer memories. For a study described in a new paper, NIST researchers used electron-beam lithography to make thousands of nickel-iron magnets, each about 200 nanometers (billionths of a meter) in diameter. Each magnet is ordinarily shaped like an ellipse, a slightly flattened circle. Researchers also made some magnets in three different egglike shapes with an increasingly pointy end. It's all part of NIST research on nanoscale magnetic materials, devices and measurement methods to support development of future magnetic data storage systems. It turns out that even small distortions in magnet shape can lead to significant changes in magnetic properties. Researchers discovered this by probing the magnets with a laser and analyzing what happens to the "spins" of the electrons, a quantum property that's responsible for magnetic orientation. Changes in the spin orientation can propagate through the magnet like waves at different frequencies. The more egg-like the magnet, the more complex the wave patterns and their related frequencies.The shifts are most pronounced at the ends of the magnets. Find out more...

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Schematic of a spherical magnetite nanoparticle shows the unexpected variation in magnetic moment between the particle's interior and exterior when subjected to a strong magnetic field. The core's moment (black lines in magenta region) lines up with the field's (light blue arrow), while the exterior's moment (black arrows in green region) forms at right angles to it.(Image Credit: NIST)

While attempting to solve one mystery about iron oxide-based nanoparticles, a research team working at the National Institute of Standards and Technology (NIST) stumbled upon another one. But once its implications are understood, their discovery may give nanotechnologists a new and useful tool. The nanoparticles in question are spheres of magnetite so tiny that a few thousand of them lined up would stretch a hair’s width, and they have potential uses both as the basis of better data storage systems and in biological applications such as hyperthermia treatment for cancer. A key to all these applications is a full understanding of how large numbers of the particles interact magnetically with one another across relatively large distances so that scientists can manipulate them with magnetism. The team applied a magnetic field to nanocrystals composed of 9 nm-wide particles, made by collaborators at Carnegie Mellon University. The field caused the particles to line up like iron filings on a piece of paper held above a bar magnet. But when the team looked closer using the neutron beam, what they saw revealed a level of complexity never seen before. “When the field is applied, the inner 7 nm-wide ‘core’ orients itself along the field’s north and south poles, just like large iron filings would,” says Kathryn Krycka, a researcher at the NIST Center for Neutron Research. “But the outer 1 nm ‘shell’ of each nanoparticle behaves differently. It also develops a moment, but pointed at right angles to that of the core.” In a word, bizarre. But potentially useful. The shells are not physically different than the interiors; without the magnetic field, the distinction vanishes. But once formed, the shells of nearby particles seem to heed one another: A local group of them will have their shells’ moments all lined up one way, but then another group’s shells will point elsewhere. This finding leads Krycka and her team to believe that there is more to be learned about the role that particle interaction has on determining internal, magnetic nanoparticle structure—perhaps something nanotechnologists can harness. “The effect fundamentally changes how the particles would talk to each other in a data storage setting,” Krycka says. “If we can control it—by varying their temperature, for example, as our findings suggest we can—we might be able to turn the effect on and off, which could be useful in real-world applications.”
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Bright red-orange photoluminescence observed from porous silicon nanoparticles with human HeLa cells, magnified 1000x and viewed in the reflection from a silicon wafer. Prepared from high-purity silicon wafers, these nanoparticles provide a non-toxic and biodegradable alternative to conventional quantum dots for in-vitro and in-vivo fluorescence imaging. The cell nuclei are stained blue.Credit: Luo Gu, Ji-Ho Park, UCSD

The first biodegradable fluorescent nanoparticle to safely image tumors and organs in live mice could be used for cancer detection and treatment in humans. Chemistry professor Michael Sailor and a team including National Science Foundation supported researchers at the University of California, San Diego, report developing the first nanoscale "quantum dot" particle that glows brightly enough to allow physicians to examine internal organs and lasts long enough to release cancer drugs before breaking down into harmless by-products. The research is another step towards mainstreaming the use of nanotechnology in medicine. Many researchers say using nanomaterials for medical reasons is the health field's next major frontier. The payoff, they say, could be lower drug toxicity, lower treatment costs, more efficient drug use, and better patient diagnosis. "There are a lot of nanomaterials that have an ability to do fluorescence imaging," says Sailor, referring to a useful property that potentially could help doctors further see organs, diagnose patients and perform surgeries. "But they're generally toxic and not appropriate for putting into people." The problem results from toxic organic or inorganic chemicals used to make the materials glow. For example, fluorescent semiconductor nanoparticles known as quantum dots can release potentially harmful heavy metals when they break down. A paramount issue in determining the efficacy of nanomaterials is the body's ability to harmlessly get rid of residual leftovers after the nanomaterial helps diagnose or treat a disease. So Sailor's team designed a new, non-toxic quantum dot nanoparticle made from silicon wafers, the same high-purity wafers that go into the manufacture of computer chips. Reseachers took the thin wafers and ran electric current through them drilling billions of pores. They then used ultrasound waves to break the wafer into bits as small as 100 nanometers. The resulting spongy silicon particles contained nano-scale features capable of displaying quantum confinement effects, or the so-called "quantum dots." The ones in the UCSD experiment glowed a reddish color when exposed to red, blue, or ultraviolet light.
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