SMA Cables Help Bridges Resist Quakes
13 May 2008, 10:36
Categories: smt-polymorphic-shape-shifters smart-materials-smt
During an earthquake, concrete-and-steel decks of bridges can become unseated from the supports they rest on, with devastating consequences for anyone on or underneath them. Now a team of international researchers, from Georgia Institute of Technology (Georgia Tech) in Atlanta and the University of Pavia European School for Advanced Studies in Reduction of Seismic Risk (ROSE School) in Italy, has demonstrated for the first time that anchoring the decks of bridges or highway overpasses with restraining cables made from shape memory alloys, rather than traditional steel cables, could help the structures survive quakes or hurricanes.
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OLED Alliance
13 May 2008, 09:57
Categories: smart-materials-smt nano-emissive-displays
DuPont and Dainippon Screen Manufacturing Co. have announced their intention to form a strategic alliance to develop integrated manufacturing equipment for printed organic light emitting diode (OLED) displays. The companies also have signed an agreement relating to their intention to bring together the elements needed – materials, technology and equipment – to mass produce OLED displays, delivering higher performance at a lower cost.
The pixels in OLED displays are created using thin films made of emissive organic materials. Compared with liquid crystal displays (LCDs), OLEDs can have much higher contrast ratios, lower power consumption (because pixels draw power only when they are in use), faster response time, and eliminate the need for the backlight and color filter. Small-size active matrix OLED displays have recently become available from several manufacturers, but the current high-cost of manufacturing limits market adoption, and constrains OLED manufacturing for large size displays.
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Scripting Nanoarchitecture: [P]rocess [M]ODs
12 May 2008, 19:12
Categories: molecular-machines--devices
A user receives a box of bots (nanobots configured to resemble a solid cube that will fit into the palm of a hand). The nanobots react through wireless signal via nano-processors hidden within their carbon bodies. User data and climate/local/global data are used to find the form. Data is then input into an evolutionary algorithm until the optimal solution is achieved. The structure links up wirelessly to a global/local p2p network to optimize itself based on given criteria. Loop for continuous optimization.
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Thermoresponsive Hydrogels Bend
12 May 2008, 13:39
Categories: smt-polymorphic-shape-shifters gels--foams
Researchers at Osaka University, Japan, have created pore-gradient hydrogels that bend in response to changes in temperature. Their ability to bend is the result of a deswelling (i.e., shrinking) property of PNIPAAm hydrogels containing silica particles. During tests, the gels transitioned from flat (Angle = 180º) at 20ºC to bent (Angle = 30º) at 40ºC, all within 60 seconds.
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Nanobots For Nanomedicine
12 May 2008, 13:02
Categories: molecular-machines--devices
The present era of nanotechnology has reached to a stage where scientists are able to develop programmable and externally controllable complex machines that are built at molecular level. Nanotechnology will enable engineers to construct sophisticated nanorobots that can navigate the human body, transport important molecules, manipulate microscopic objects and communicate with physicians by way of miniature sensors, motors, manipulators, power generators and molecular-scale computers. The idea to build a medical nanorobot comes from the fact that the body has natural nanodevices; neutrophiles, lymphocytes and white blood cells constantly rove about the body, repairing damaged tissues, attacking and eating invading microorganisms, and sweeping up foreign particles for various organs to break down or excrete.
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Supramolecular Polymers Self-Assemble
12 May 2008, 11:52
Categories: polymers self-assembly
Researchers at the Eindhoven University of Technology, the Netherlands, have created supramolecular polymers that differ from conventional polymers. Most polymers are made up of long molecular chains that are connected to each other by covalent bonds, whereby electrons are shared by atoms in the chains. The researchers were able to create a supramolecular polymer that spontaneously forms from different kinds of self-assembling monomers into a polymeric network.
In the image above, carbon atoms are shown in grey, nitrogen in blue, oxygen in red, and hydrogen in white.
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All-Terrain Fluids Move Uphill
11 May 2008, 11:08
Categories: NEMS--MEMS superhydrophobicphilic
Canadian chemists have developed an all-terrain droplet actuation (ATDA) method to move droplets across chips at a wide range of angles. Aaron Wheeler and colleagues at the University of Toronto say digital microfluidic devices using ATDA could be used to move fluids rapidly between different environments, for example to cycle between heating and cooling.
Wheeler developed ATDA on flexible, water-repellent polyimide surfaces, clad with copper, which can be bent into a variety of shapes including steps, twists and overhangs. The fluid beads are moved by sequentially activating a series of electrode pairs, which is thought to pull the droplet forward by reducing water repellence in front of the droplet. This process gives the team full control of the droplet, including up and down vertical surfaces.
To sustain the droplet, a 50 nm thick hydrophobic layer was deposited by spin-coating poly(dimethylsiloxane) (PDMS) (6000 rpm, 1 min) and Teflon-AF1600 (1% resin in Fluorinert FC-40, 2000 rpm, 1 min) on flexible PCB substrates.
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Assembling Spider Silk
11 May 2008, 11:03
Categories: biomimicry nanofibers
A new microfluidics device that works like a spider’s silk duct might finally lead the way to producing industrial quantities of high-quality artificial spider silk. Spider silk is super-light, super-strong and elastic too. Existing human materials lack its useful combination of properties, and proposed uses span everything from bulletproof vests to optic fibres. Researchers have struggled for years to find an industrial process to make spider silk, and have tried everything from making it in a lab dish to creating silk-secreting goats.
Now a group of researchers at the Technical University of Munich and the University of Bayreuth, Germany, has demonstrated a new method of production – an artificial version of the ducts spiders use to “spin” the silk. The artificial duct is a glass microfluidic chip shot through with tiny tubes. Inside the chip, two proteins found in silk from the European garden spider (_Araneus diadematus_) – known as ADF3 and ADF4 – flow along tiny tubes and are exposed to a phosphate salt solution that makes them aggregate into tiny spheres 1 to 5 micrometres across. A sudden jump in acidity and phosphate concentration then partially breaks open the spheres, allowing the proteins to latch together into chains. At this point, the flow speed increases and draws out the proteins into long silk fibres.
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The World's Fastest Nanomotors
11 May 2008, 10:35
Categories: molecular-machines--devices nanotubes--fullerenes
Researchers at Arizona State University claim they have developed nanomotors that are ten times more powerful than the engines that are available today. The result: Nanomachines with these new engines are twice as fast. The new motors are built with platinum and carbon nanotubes and are powered by a fuel that uses hydrazine as an additive. The project group claims that the modification is enough to put nanomotors into practical use. The use of carbon nanotubes increases the speed to 60 micrometers per second, while hydrazine boost the performance to 94—200 micrometers per second (which is about 13—28 inches per hour).
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Three to Four Nanotech Products Released Weekly
10 May 2008, 14:46
Categories: nanoparticles other
While polls show most Americans know little or nothing about nanotechnology, the Consumer Products Inventory database maintained by the Project on Emerging Nanotechnologies (PEN) shows that new nanotechnology consumer products are coming on the market at the rate of three to four per week.
The number of consumer products using nanotechnology has grown from 212 to 609 since PEN launched the world’s first online inventory of manufacturer-identified nanotech goods in March 2006. Health and fitness items, which include cosmetics and sunscreens, represent 60 percent of inventory products. There are 35 automotive products in the PEN inventory, and silver is the most cited nanomaterial used. Silver nanoparticles, or NanoSilver, is found in 143 products or over 20 percent of the inventory. Carbon, including carbon nanotubes and fullerenes, is the second highest nanoscale material cited.
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NanoSilver Fights Microbes
10 May 2008, 14:42
Categories: nanoparticles safety--security
Silver has long been known to be a good antimicrobial material, and nanoparticles consisting of this metal are no different. Silver nanoparticles—a small cluster of silver atoms less than 100 nanometers—destroy the cell walls of bacteria and other microbes. Numerous products include NanoSilver, and paints are now being embedded with silver nanoparticles in the hope that hospitals will coat their walls and countertops to fight infection (according to the U.S. Centers for Disease Control and Prevention, more than one million people a year contract bacterial infections in hospitals).
“Nanoparticles are very small and they are interacting with the bacteria and rupturing the cell wall,” says chemist George John of The City College of New York and lead author of a study, published recently in the journal Nature Materials. This rupture of the cell wall kills the bacteria, he explains.
Although there are currently no restrictions on using silver nanoparticles, some scientists are concerned that silver nanoparticles may not be as harmless as they appear. Little research has been done on their health and environmental effects, and silver kills good microorganisms along with the bad.
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CNTs Remove Bacteria and Viruses from Water
10 May 2008, 11:03
Categories: filtration nanotubes--fullerenes
A few cents worth of single-walled carbon nanotubes (SWNTs) could be sufficient to stop viral and bacterial pathogens in their tracks and provide a point-of-use treatment for contaminated water. A Yale University research team has developed a prototype filter that consists of a polymer microporous membrane covered with a thin layer (2–6 µm) of SWNTs. The design allows high-water fluxes and low operating pressures, which will help to keep operating costs down. Results show that the SWNT filter exhibits very high removal of viruses (over 5 log, or 99.999%). Furthermore, the SWNT filter not only completely retains E. coli, but also renders the bacteria inactive.
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Nanotubes Measure Chilli Sauce Hotness
10 May 2008, 11:00
Categories: nanotubes--fullerenes sensors
Oxford chemists have found a way of using carbon nanotubes (CNTs) to judge the heat of chilli sauces by measuring the levels of capsaicinoids, the substances that make chillies hot. The current industry procedure is to use a panel of taste-testers, and is highly subjective.
The Oxford CNT technology might soon be available commercially as a cheap, disposable sensor for use in the food industry. Capsaicinoids are adsorbed onto multi-walled carbon nanotube electrodes. Then the team measures the current change as the capsaicinoids are oxidised by an electrochemical reaction, and this reading can be translated into Scoville units (a “heat” rating system used in the industry). The technique is called adsorptive stripping voltammetry (ASV), and is a relatively simple electrochemical method.
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Nanowires Grown for Ultra-Thin Displays
10 May 2008, 10:58
Categories: nano-emissive-displays nanotubes--fullerenes
Researchers at the University of Illinois in Urbana Champaign have developed a simple process to grow copper nanowires on different surfaces; each wire is between 70 nanometers and 250 nanometers wide. The nanowire arrays could find use in field-emission displays (FED), a new type of display technology that promises to provide brighter, more vivid pictures than existing flat-panel displays.
FEDs work in a manner that is similar, in principle, to cathode-ray-tube (CRTs) televisions, but they are only a few millimeters thick and use millions of tiny electron emitters instead of using a single electron gun. In FEDs, the copper nanowires would be used to fire electrons at red, green and blue phosphor particles that are coated on a screen, lighting them up. The nanowires are uniform and have a very pointed tip, and they emit electrons at low voltages, unlike the tungsten filament used in conventional, bulky CRTs, which require many kiloVolts.
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Nanotechnology Roundup
9 May 2008, 18:10
Categories: other
Nanomaterials have a relatively larger surface area when compared to the same mass of material in bulk form, which can make the materials more chemically reactive and affect their strength or electrical properties. Additionally, quantum effects can begin to dominate the behavior of matter at the nanoscale, affecting the optical, electrical and magnetic behavior of materials. For example, metals with a so-called grain size of around 10 nanometers are as much as seven times harder and tougher than their ordinary counterparts with grain sizes in the hundreds of nanometers.
Despite its promise, one of the main problems facing nanotechnology is the confusion about its definition. Most definitions revolve around the study and control of phenomena and materials at length scales between 1 and 100 nanometers, and the most overused comparison you read about all the time is that with a human hair, which is about 80,000 nm wide. This broad, dimension-based definition has not been entirely useful and is sorely in need of an update to avoid confusion. Some definitions include a reference to molecular systems and devices, and often include “functional systems”. Another important criteria for the definition is the requirement that nanostructures be man-made, and that a nanostructure has special properties that are exclusively due to its nanoscale proportions.
Nanowerk has found a good definition that springs from a recently published article on nanomedicine patent protection. In addition to being practical, the definition is unconstrained by size limitations (source):
The design, characterization, production, and application of structures, devices, and systems by controlled manipulation of size and shape at the nanometer scale (atomic, molecular, and macromolecular scale) that produces structures, devices, and systems with at least one novel/superior characteristic or property.
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Nanowerk also notes that nanotechnology will evolve over a series of technological generations, with each innovation providing a means to produce better products:
First Generation (beginning ∼2000): passive nanostructures, illustrated by nanostructured coatings, nanoparticles, dispersion of nanoparticles, nanocomposites, and bulk nanostructured materials made of metals, polymers, ceramics; bio-building blocks.
Second Generation (beginning ∼2005): active nanostructures, illustrated by transistors, amplifiers, biological and non-biological sensors, actuators, and adaptive structures.
Third Generation (beginning ∼2010): three-dimensional nanosystems and systems of nanosystems using various synthesis and assembly techniques such as bio-assembly, networking at the nanoscale, and multi-scale architectures.
Fourth Generation (beginning ∼2015): materials by design and heterogeneous molecular nanosystems, where each molecule in the nanosystem has a specific structure and plays a different role. Molecules will be used as devices, and from their engineered structures and architectures will emerge fundamentally new functions.
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Luminescent Nanowires
9 May 2008, 17:36
Categories: smt-luminescent-light-emit
Gallium oxide (Ga2O3) nanowires have been grown by scientists at the National Tsing Hua University Nanomatarials Laboratory, in Taiwan. The linear structures emit blue light (wavelength: 400–500 nm) when irradiated with an ultraviolet source (wavelength: 254 nm) and provide a much clearer reference pattern compared with a series of quantum dots.
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Nanowiring Devices with Boron Clusters in Graphene
9 May 2008, 17:27
Categories: nanotubes--fullerenes molecular-machines--devices
Jens Kunstmann of the Max-Planck Institute in Stuttgart, with colleagues in Germany, Italy, and Turkey, has proposed a “blueprint” for graphene-based nanodevices of the future. The model involves using alternating chains of B7 boron clusters to connect various parts of a semiconducting graphene substrate (boron and carbon are compatible at the nanoscale). The small planar clusters act as metallic islands (i.e., electrically conductive zones) embedded in the graphene substrate, and can allow electron transport through the substrate. The concept is very similar to that routinely employed in silicon-based integrated circuits, but the resulting graphene-based devices would be several orders of magnitude smaller.
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Design of a Nanoassembly System
9 May 2008, 16:07
Categories: molecular-manufacturing molecular-machines--devices
In his 1986 book, Engines of Creation, K. Eric Drexler set down the long-term aim of nanotechnology – to create an assembler, a microscopic robot that could construct products from a stock of atoms and molecules. For the last two decades, researchers who recognized the benefits of achieving molecular manufacturing have used top-down and bottom-up methods to develop molecular machines. The top-down approach is seen in the manipulative power of the atomic force microscope (AFM), a machine that can observe and handle single atoms, and the bottom-up approach uses chemistry to build molecular machinery. However, neither the top-down nor the bottom-up approach is yet to fulfill Drexler’s prophecy of functional nanobots that can construct other machines and useful products.
The first real steps towards building a microscopic device that can construct nanomachines have recently been taken by researchers at the National Institute of Standards and Technology (NIST) in the US. Soon to be published in the peer-reviewed publication International Journal of Nanomanufacturing, researchers from the NIST’s Intelligent Systems Division have described an early, proto-prototype for a nanoscale assembler.
Jason Gorman, of the Intelligent Systems Division, concedes that, “Nanoassembly is extremely challenging.” Yet the rewards could be enormous with the ultimate potential of creating a technology that can construct almost any material from atoms and molecules from super-strong but incredibly lightweight construction materials to a molecular computer or even nanobots that can make other nanobots to solve global problems, such as food, water, and energy shortages. “Our demonstration is still a work in progress,” says Gorman, “you might describe it as a ‘proto-prototype’ for a nanoassembler.”
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Institute to Build Molecular Factories
9 May 2008, 14:59
Categories: molecular-machines--devices
Researchers from a wide range of disciplines at Eindhoven University of Technology (TU/e) will be joining forces at their new Institute for Complex Molecular Systems. The researchers will be investigating the exact mechanism behind self-organization, the principle behind all life on earth, and plan to use this knowledge to build molecular factories that could produce the next generation of catalysts, photosynthetic systems, nanocontainers, and functional materials. The Executive Board of TU/e has allocated 15 million euros to the Institute over the next 10 years.
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The Ionosphere in 4D
9 May 2008, 14:48
Categories: nanoparticles
NASA has released to the general public a new “4D” live model of Earth’s ionosphere. Without leaving home, anyone can fly through the layer of ionized gas that encircles Earth at the edge of space itself. All that’s required is a connection to the Internet.
The 4D Ionosphere project was developed by researchers at Space Environment Technologies, Inc. of California, Space Environment Corp. of Utah, and the US Air Force.
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Launch the 4D Ionosphere
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