David Kirkpatrick

July 5, 2010

The latest in smart textiles

The entire piece is a nice very short primer on the concept of smart textiles, but real news is a breakthrough in the very fibers smart textiles are woven from.

From the link:

But that’s a fiddly, time-consuming process. One thing that could help is more useful fibres. And today Jian Feng Gu from Huazhong University of Science and Technology in China and couple of buddies reveal one that could help.

Their idea is to create a simple rolled capacitor from a sheet of conducting polymer sandwiched between two insulating sheets of low density polyethylene. They then roll this sandwich into a cylinder and encase it in high density polyethylene.

There’s nothing unusual about this kind of rolled capacitor. But what Gu and co do next is. They heat it and then extrude it through a tiny hole to form a fibre with a diameter of less than a millimetre.

If the conditions are just right, the plastics all stretch in exactly the same way so that the internal structure of the fibre is just a smaller version of the original.

And that’s exactly what happens. Gu and co say their fibre is soft and flexible and has a capacitance some 1000 times greater than an equivalent co-axial cable.

February 20, 2010

Paper batteries and eTextiles

The 2010 AAAS (American Association for the Advancement of Science) annual meeting is going on as I type, so there is a lot of news coming out fast and furious from the conference. I’m going to try and restrain myself and only post what really strikes my fancy, or what sounds like a game-changing advancement in any particular field.

Like I regularly do, this news will presented in the form of the raw press release. Yeah, it’s a bit lazy to drop the release on you with minimal, if any, commentary from me, but I don’t want to be a gatekeeper of the information being put out and I don’t want to spin the news by selectively writing from a release. With a raw release you get all the information the organization/scientist/whoever put the release out wanted to make public and you can use that information as you see fit. Do keep in mind any release is going to have some manner of bias, even science releases, so read them with that in mind, but do enjoy this exciting news as it comes out.

This release is on nanotechnology and how it is allowing for paper batteries and supercapacitors and is creating a new fabric technology called “eTextiles.”

The release:

Nanotechnology sparks energy storage on paper and cloth

Stanford researcher Yi Cui and his team are re-conceptualizing batteries using nanotechnology

IMAGE: Bing Hu, a post-doctoral fellow in Yi Cui’s research group at Stanford, prepares a small square of ordinary paper with an ink that will deposit nanotubes on the surface that…

Click here for more information.

By dipping ordinary paper or fabric in a special ink infused with nanoparticles, Stanford engineer Yi Cui has found a way to cheaply and efficiently manufacture lightweight paper batteries and supercapacitors (which, like batteries, store energy, but by electrostatic rather than chemical means), as well as stretchable, conductive textiles known as “eTextiles” – capable of storing energy while retaining the mechanical properties of ordinary paper or fabric.

While the technology is still new, Cui’s team has envisioned numerous functional uses for their inventions. Homes of the future could one day be lined with energy-storing wallpaper. Gadget lovers would be able to charge their portable appliances on the go, simply plugging them into an outlet woven into their T-shirts. Energy textiles might also be used to create moving-display apparel, reactive high-performance sportswear and wearable power for a soldier’s battle gear.

The key ingredients in developing these high-tech products are not visible to the human eye. Nanostructures, which can be assembled in patterns that allow them to transport electricity, may provide the solutions to a number of problems encountered with electrical storage devices currently available on the market.

The type of nanoparticle used in the Cui group’s experimental devices varies according to the intended function of the product – lithium cobalt oxide is a common compound used for batteries, while single-walled carbon nanotubes, or SWNTs, are used for supercapacitors.

Cui, an assistant professor of materials science and engineering at Stanford, leads a research group that investigates new applications of nanoscale materials. The objective, said Cui, is not only to supply answers to theoretical inquiries but also to pursue projects with practical value. Recently, his team has focused on ways to integrate nanotechnology into the realm of energy development.

“Energy storage is a pretty old research field,” said Cui. “Supercapacitors, batteries – those things are old. How do you really make a revolutionary impact in this field? It requires quite a dramatic difference of thinking.”

While electrical energy storage devices have come a long way since Alessandro Volta debuted the world’s first electrical cell in 1800, the technology is facing yet another revolution. Current methods of manufacturing energy storage devices can be capital intensive and environmentally hazardous, and the end products have noticeable performance constraints – conventional lithium ion batteries have a limited storage capacity and are costly to manufacture, while traditional capacitors provide high power but at the expense of energy storage capacity.

With a little help from new science, the batteries of the future may not look anything like the bulky metal units we’ve grown accustomed to. Nanotechnology is favored as a remedy both for its economic appeal and its capability to improve energy performance in devices that integrate it. Replacing the carbon (graphite) anodes found in lithium ion batteries with anodes of silicon nanowires, for example, has the potential to increase their storage capacity by 10 times, according to experiments conducted by Cui’s team.

Silicon had previously been recognized as a favorable anode material because it can hold a larger amount of lithium than carbon. But applications of silicon were limited by its inability to sustain physical stress – namely, the fourfold volume increase that silicon undergoes when lithium ions attach themselves to a silicon anode in the process of charging a battery, as well as the shrinkage that occurs when lithium ions are drawn out as it discharges. The result was that silicon structures would disintegrate, causing anodes of this material to lose much if not all of their storage capacity.

Cui and collaborators demonstrated in previous publications in Nature, Nanotechnology and Nano Letters that the use of silicon nanowire battery electrodes, mechanically capable of withstanding the absorption and discharge of lithium ions, was one way to sidestep the problem.

The findings hold promise for the development of rechargeable lithium batteries offering a longer life cycle and higher energy capacity than their contemporaries. Silicon nanowire technology may one day find a home in electric cars, portable electronic devices and implantable medical appliances.

Cui now hopes to direct his research toward studying both the “hard science” behind the electrical properties of nanomaterials and designing real-world applications.

“This is the right time to really see what we learn from nanoscience and do practical applications that are extremely promising,” said Cui. “The beauty of this is, it combines the lowest cost technology that you can find to the highest tech nanotechnology to produce something great. I think this is a very exciting idea … a huge impact for society.”

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The Cui group’s latest research on energy storage devices was detailed in papers published in the online editions of the Proceedings of the National Academy of Sciences in December 2009 (“Highly Conductive Paper for Energy-Storage Devices”) and Nano Letters in January 2010 (“Stretchable, Porous and Conductive Energy Textiles”).

Cui’s talk at the symposium “Nanotechnology: Will Nanomaterials Revolutionize Energy Applications?” is scheduled for 9:50 a.m. Feb. 20 in Room 1B of the San Diego Convention Center.

Video/photos:
Conductive eTextiles: Stanford finds a new use for cloth
http://news.stanford.edu/news/2010/february1/batteries-from-cloth-020510.html

At Stanford, nanotubes + ink + paper = instant battery
http://news.stanford.edu/news/2009/december7/nanotubes-ink-paper-120709.html

December 15, 2008

Nanotech and smart textiles

A promising use of carbon nanotubes.

The release:

Nature, nanotechnology fuse in electric yarn that detects blood

ANN ARBOR, Mich.— A carbon nanotube-coated “smart yarn” that conducts electricity could be woven into soft fabrics that detect blood and monitor health, engineers at the University of Michigan have demonstrated.

“Currently, smart textiles are made primarily of metallic or optical fibers. They’re fragile. They’re not comfortable. Metal fibers also corrode. There are problems with washing such electronic textiles. We have found a much simpler way—an elegant way—by combining two fibers, one natural and one created by nanotechnology,” said Nicholas Kotov, a professor in the departments of Chemical Engineering, Materials Science and Engineering and Biomedical Engineering.

Kotov and Bongsup Shim, a doctoral student in the Department of Chemical Engineering, are among the co-authors of a paper on this material currently published online in Nano Letters.

To make these “e-textiles,” the researchers dipped 1.5-millimeter thick cotton yarn into a solution of carbon nanotubes in water and then into a solution of a special sticky polymer in ethanol. After being dipped just a few times into both solutions and dried, the yarn was able to conduct enough power from a battery to illuminate a light-emitting diode device.

“This turns out to be very easy to do,” Kotov said. “After just a few repetitions of the process, this normal cotton becomes a conductive material because carbon nanotubes are conductive.”

The only perceptible change to the yarn is that it turned black, due to the carbon. It remained pliable and soft.

In order to put this conductivity to use, the researchers added the antibody anti-albumin to the carbon nanotube solution. Anti-albumin reacts with albumin, a protein found in blood. When the researchers exposed their anti-albumin-infused smart yarn to albumin, they found that the conductivity significantly increased. Their new material is more sensitive and selective as well as more simple and durable than other electronic textiles, Kotov said.

Clothing that can detect blood could be useful in high-risk professions, the researchers say. An unconscious firefighter, ambushed soldier, or police officer in an accident, for example, couldn’t send a distress signal to a central command post. But the smart clothing would have this capability.

Kotov says a communication device such as a mobile phone could conceivably transmit information from the clothing to a central command post.

“The concept of electrically sensitive clothing made of carbon-nanotube-coated cotton is flexible in implementations and can be adapted for a variety of health monitoring tasks as well as high performance garments,” Kotov said.

It is conceivable that clothes made out of this material could be designed to harvest energy or store it, providing power for small electronic devices, but such developments are many years away and pose difficult challenges, the engineers say.

 

###

 

The paper published online in Nano Letters is titled, “Smart Electronic Yarns and Wearable Fabrics for Human Biomonitoring Made by Carbon Nanotube Coating with Polyelectrolytes.” Other contributors are with Jiangnan University in China.

This research was funded by the National Science Foundation, the Office of Naval Research, the Air Force Office of Scientific Research and the National Natural Science Foundation of China.

For more information: Nicholas Kotov: http://www.engin.umich.edu/dept/cheme/people/kotov.html

Michigan Engineering

The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At more than $130 million annually, its engineering research budget is one of largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world class Lurie Nanofabrication Facility. For more information, visit: http://www.engin.umich.edu/.

July 12, 2010

Fibers that detect and produce sound

The latest in the world of smart textiles is sound detecting and producing fibers.

From the second link, the release:

MIT researchers create fibers that can detect and produce sound

Could lead to clothes that capture speech, tiny filaments to measure blood flow or pressure

IMAGE: MIT researchers have demonstrated that they can manufacture acoustic fibers with flat surfaces, like those shown here, as well as fibers with circular cross sections. The flat fibers could prove…

Click here for more information.

CAMBRIDGE, Mass. — For centuries, “man-made fibers” meant the raw stuff of clothes and ropes; in the information age, it’s come to mean the filaments of glass that carry data in communications networks. But to Yoel Fink, an Associate professor of Materials Science and principal investigator at MIT’s Research Lab of Electronics, the threads used in textiles and even optical fibers are much too passive. For the past decade, his lab has been working to develop fibers with ever more sophisticated properties, to enable fabrics that can interact with their environment.

In the August issue of Nature Materials, Fink and his collaborators announce a new milestone on the path to functional fibers: fibers that can detect and produce sound. Applications could include clothes that are themselves sensitive microphones, for capturing speech or monitoring bodily functions, and tiny filaments that could measure blood flow in capillaries or pressure in the brain. The paper, whose authors also include Shunji Egusa, a former postdoc in Fink’s lab, and current lab members Noémie Chocat and Zheng Wang, appeared on Nature Materials‘ website on July 11.

Ordinary optical fibers are made from a “preform,” a large cylinder of a single material that is heated up, drawn out, and then cooled. The fibers developed in Fink’s lab, by contrast, derive their functionality from the elaborate geometrical arrangement of several different materials, which must survive the heating and drawing process intact.

The heart of the new acoustic fibers is a plastic commonly used in microphones. By playing with the plastic’s fluorine content, the researchers were able to ensure that its molecules remain lopsided — with fluorine atoms lined up on one side and hydrogen atoms on the other — even during heating and drawing. The asymmetry of the molecules is what makes the plastic “piezoelectric,” meaning that it changes shape when an electric field is applied to it.

In a conventional piezoelectric microphone, the electric field is generated by metal electrodes. But in a fiber microphone, the drawing process would cause metal electrodes to lose their shape. So the researchers instead used a conducting plastic that contains graphite, the material found in pencil lead. When heated, the conducting plastic maintains a higher viscosity — it yields a thicker fluid — than a metal would.

Not only did this prevent the mixing of materials, but, crucially, it also made for fibers with a regular thickness. After the fiber has been drawn, the researchers need to align all the piezoelectric molecules in the same direction. That requires the application of a powerful electric field — 20 times as powerful as the fields that cause lightning during a thunderstorm. Anywhere the fiber is too narrow, the field would generate a tiny lightning bolt, which could destroy the material around it.

Despite the delicate balance required by the manufacturing process, the researchers were able to build functioning fibers in the lab. “You can actually hear them, these fibers,” says Chocat, a graduate student in the materials science department. “If you connected them to a power supply and applied a sinusoidal current” — an alternating current whose period is very regular — “then it would vibrate. And if you make it vibrate at audible frequencies and put it close to your ear, you could actually hear different notes or sounds coming out of it.” For their Nature Materials paper, however, the researchers measured the fiber’s acoustic properties more rigorously. Since water conducts sound better than air, they placed it in a water tank opposite a standard acoustic transducer, a device that could alternately emit sound waves detected by the fiber and detect sound waves emitted by the fiber.

In addition to wearable microphones and biological sensors, applications of the fibers could include loose nets that monitor the flow of water in the ocean and large-area sonar imaging systems with much higher resolutions: A fabric woven from acoustic fibers would provide the equivalent of millions of tiny acoustic sensors.

Zheng, a research scientist in Fink’s lab, also points out that the same mechanism that allows piezoelectric devices to translate electricity into motion can work in reverse. “Imagine a thread that can generate electricity when stretched,” he says.

Ultimately, however, the researchers hope to combine the properties of their experimental fibers in a single fiber. Strong vibrations, for instance, could vary the optical properties of a reflecting fiber, enabling fabrics to communicate optically.

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Source: “Multimaterial piezoelectric fibres.” S. Egusa, Z. Wang, N. Chocat, Z. M. Ruff, A. M. Stolyarov, D. Shemuly, F. Sorin, P. T. Rakich, J. D. Joannopoulos, and Y. Fink. Nature Materials, 11 July 2010.

May 3, 2010

Recovering lost art through technology

Undoing 16th century vandalism in the name of religion.

The release:

Reveal-all-scanner for works of art

Research News May 2010

Painted-over murals were thought to be irretrievably lost because conventional methods are seldom suitable to rendering the hidden works visible without causing damage. Research scientists now aim to reveal the secrets of these paintings non-destructively using terahertz beams.

Link: download picture

Many church paintings are hidden from sight because they were painted over centuries ago. In the 16th century, for instance, Reformation iconoclasts sought to obscure the religious murals, while in later times the iconoclast images often were painted over once again. Several layers of paintings from various epochs can now be found superimposed on top of each other. If mechanical methods are used to uncover these pictures there is always a risk that the original work will be damaged. What’s more, the more recent layers and pictures on top of the original, which are also worthy of preservation, would be destroyed. Research scientists at the Fraunhofer Institute for Material and Beam Technology IWS in Dresden are now working on a non-destructive method for rendering these works visible, which involves the use of terahertz (THz) radiation. In the TERAART project funded by the German federal ministry of education and research (BMBF) they are cooperating with Dresden University of Technology, the FIDA Institute for Historic Preservation in Potsdam and the Dresden Academy of Fine Arts.

»We use THz radiation because it can penetrate the plaster and lime wash even if the layer is relatively thick. Unlike UV radiation for example, THz radiation does not damage the work of art. Infrared beams cannot be considered because they do not penetrate deep enough. Microwaves offer no alternative either, because they do not achieve the necessary width and depth resolution,« explains Dr. Michael Panzner, scientist at the IWS. A mobile system that can be used anywhere was developed to conduct the examinations. It consists of a scanner with two measuring heads which travels contactlessly over the wall. One measuring head transmits the radiation, the other picks up the reflected beams. The researchers were supported by the Fraunhofer Institute for Physical Measurement Techniques IPM, which built the adapted THz component.

»To produce the THz radiation we use a femtosecond laser incorporating the design principle of a fiber laser. The THz time domain spectroscopy technique applied by us utilizes the short electromagnetic pulses with a duration of just one to two picoseconds produced by the femtosecond laser. Each layer and each pigment reflects these pulses differently so that both a picture contrast as well as depth information can be obtained,« says Panzner. »The measured results provide information for example about the thickness of the layers, what pigments were used and how the colors are arranged. A specially developed software system puts the measured results together to form a picture displaying the structure of the concealed paintings.«

On a test wall, on which paintings in various types of paint were painted over with distemper, the scientists have already succeeded in revealing the structures of the concealed pictures. The next step will be to conduct a practical test in a church. The experts are also confident of being able to use THz radiation to detect the presence of carcinogenic biocides on and in works of art made of wood or textiles. »Preservationists will be very interested in our reveal-all-scanner for works of art, « affirms Panzner.

March 9, 2010

More on electric fabrics

Filed under: et.al. — Tags: , , , , — David Kirkpatrick @ 5:18 pm

This time from Cornell, and sounds practically market-ready. Hit this link for previous blogging on the topic of electric fabrics.

From the first link, the release:

Cotton is the fabric of your lights…your iPod…your MP3 player…your cell phone

ITHACA, N.Y. — Consider this T-shirt: It can monitor your heart rate and breathing, analyze your sweat and even cool you off on a hot summer’s day. What about a pillow that monitors your brain waves, or a solar-powered dress that can charge your ipod or MP4 player? This is not science fiction – this is cotton in 2010.

Now, the laboratory of Juan Hinestroza, assistant professor of Fiber Science and Apparel Design, has developed cotton threads that can conduct electric current as well as a metal wire can, yet remain light and comfortable enough to give a whole new meaning to multi-use garments. This technology works so well that simple knots in such specially treated thread can complete a circuit – and solar-powered dress with this technology literally woven into its fabric will be featured at the annual Cornell Design League Fashion Show on Saturday, March 13 at Cornell University’s Barton Hall.

Using multidisciplinary nanotechnology developed at Cornell in collaboration with the universities at Bologna and Cagliari, Italy, Hinestroza and his colleagues developed a technique to permanently coat cotton fibers with electrically conductive nanoparticles. “We can definitively have sections of a traditional cotton fabric becoming conductive, hence a great myriad of applications can be achieved,” Hinestroza said.

“The technology developed by us and our collaborators allows cotton to remain flexible, light and comfortable while being electronically conductive,” Hinestroza said. “Previous technologies have achieved conductivity but the resulting fiber becomes rigid and heavy. Our new techniques make our yarns friendly to further processing such as weaving, sewing and knitting.”

This technology is beyond the theory stage. Hinestroza’s student, Abbey Liebman, was inspired by the technology enough to design a dress that actually uses flexible solar cells to power small electronics from a USB charger located in the waist. The charger can power a smartphone or an MP3 player.

“Instead of conventional wires, we are using our conductive cotton to transmit the electricity — so our conductive yarns become part of the dress,” Hinestroza said. “Cotton used to be called the ‘fabric of our lives’ but based on these results, we can now call it ‘The fabric of our lights.'”

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For more information about the Cornell Design League annual fashion show, visit: http://www.rso.cornell.edu/CDesignL/shows.php

February 12, 2010

Nanogenerators and electric clothes

(Number two of two posts on nanotechnology and electricity. Hit this link for part one)

The idea of smart clothes has been around for ages. Looks like this might just be a breakthrough to electric clothing becoming a reality.

That oughta bring a whole new meaning to “social networking.” Thank you, thank you, I’ll be here all weekend. Be sure and come back tomorrow for the complimentary Saturday buffet and half-price happy hour.

The release:

New fiber nanogenerators could lead to electric clothing

By Sarah Yang, Media Relations | 12 February 2010

BERKELEY — In research that gives literal meaning to the term “power suit,” University of California, Berkeley, engineers have created energy-scavenging nanofibers that could one day be woven into clothing and textiles.

These nano-sized generators have “piezoelectric” properties that allow them to convert into electricity the energy created through mechanical stress, stretches and twists.

“This technology could eventually lead to wearable ‘smart clothes’ that can power hand-held electronics through ordinary body movements,” said Liwei Lin, UC Berkeley professor of mechanical engineering and head of the international research team that developed the fiber nanogenerators.

Because the nanofibers are made from organic polyvinylidene fluoride, or PVDF, they are flexible and relatively easy and cheap to manufacture.

Although they are still working out the exact calculations, the researchers noted that more vigorous movements, such as the kind one would create while dancing the electric boogaloo, should theoretically generate more power. “And because the nanofibers are so small, we could weave them right into clothes with no perceptible change in comfort for the user,” said Lin, who is also co-director of the Berkeley Sensor and Actuator Center at UC Berkeley.

The fiber nanogenerators are described in this month’s issue of Nano Letters, a peer-reviewed journal published by the American Chemical Society.

The goal of harvesting energy from mechanical movements through wearable nanogenerators is not new. Other research teams have previously made nanogenerators out of inorganic semiconducting materials, such as zinc oxide or barium titanate. “Inorganic nanogenerators — in contrast to the organic nanogenerators we created — are more brittle and harder to grow in significant quantities,” Lin said.

The tiny nanogenerators have diameters as small as 500 nanometers, or about 100 times thinner than a human hair and one-tenth the width of common cloth fibers. The researchers repeatedly tugged and tweaked the nanofibers, generating electrical outputs ranging from 5 to 30 millivolts and 0.5 to 3 nanoamps.

Furthermore, the researchers report no noticeable degradation after stretching and releasing the nanofibers for 100 minutes at a frequency of 0.5 hertz (cycles per second).

Lin’s team at UC Berkeley pioneered the near-field electrospinning technique used to create and position the polymeric nanogenerators 50 micrometers apart in a grid pattern. The technology enables greater control of the placement of the nanofibers onto a surface, allowing researchers to properly align the fiber nanogenerators so that positive and negative poles are on opposite ends, similar to the poles on a battery.

Without this control, the researchers explained, the negative and positive poles might cancel each other out and reducing energy efficiency.

The researchers demonstrated energy conversion efficiencies as high as 21.8 percent, with an average of 12.5 percent.

“Surprisingly, the energy efficiency ratings of the nanofibers are much greater than the 0.5 to 4 percent achieved in typical power generators made from experimental piezoelectric PVDF thin films, and the 6.8 percent in nanogenerators made from zinc oxide fine wires,” said the study’s lead author, Chieh Chang, who conducted the experiments while he was a graduate student in mechanical engineering at UC Berkeley.

“We think the efficiency likely could be raised further,” Lin said. “For our preliminary results, we see a trend that the smaller the fiber we have, the better the energy efficiency. We don’t know what the limit is.”

Other co-authors of the study are Yiin-Kuen Fuh, a UC Berkeley graduate student in mechanical engineering; Van H. Tran, a graduate student at the Technische Universität München (Technical University of Munich) in Germany; and Junbo Wang, a researcher at the Institute of Electronics at the Chinese Academy of Sciences in Beijing, China.

The National Science Foundation and the Defense Advanced Research Projects Agency helped support this research.

fiber nanogenerator
Shown is a fiber nanogenerator on a plastic substrate created by UC Berkeley scientists. The nanofibers can convert energy from mechanical stresses and into electricity, and could one day be used to create clothing that can power small electronics. (Chieh Chang, UC Berkeley)

December 4, 2009

Macro yarn from nano fibers

Step aside Kevlar, your replacement just clocked in.

This nanotech product looks to have immediate practical applications. Anyone who was a serious tennis player quite some ago ought to remember the Prince Boron racket. Outrageously priced at $500 in a time when cracking three figures was very, very expensive for tennis equipment. I wonder how much an updated version using this boron nitride nanofiber yarn would command?

From the first link, the release:

Visualization of helium-4 and beryllium nuclei.

A yarn spun of boron-nitride nanotubes suspends a quarter.

NEWPORT NEWS, VA, Dec. 2 –Researchers have used lasers to create the first practical macroscopic yarns from boron nitride fibers, opening the door for an array of applications, from radiation-shielded spacecraft to stronger body armor, according to a just-published study.

Researchers at NASA’s Langley Research Center, the Department of Energy’s Thomas Jefferson National Accelerator Facility and the National Institute of Aerospace created a new technique to synthesize high-quality boron-nitride nanotubes (BNNTs). They are highly crystalline and have a small diameter. They also structurally contain few walls and are very long. Boron nitride is the white material found in clown make-up and face powder.

“Before, labs could make really good nanotubes that are are short or really crummy ones that are long. We’ve developed a technique that makes really good ones that are really long,” said Mike Smith, a staff scientist at NASA’s Langley Research Center.

The synthesis technique, called the pressurized vapor/condenser (PVC) method, was developed with Jefferson Lab’s Free-Electron Laser and later perfected using a commercial welding laser. In this technique, the laser beam strikes a target inside a chamber filled with nitrogen gas. The beam vaporizes the target, forming a plume of boron gas. A condenser, a cooled metal wire, is inserted into the boron plume. The condenser cools the boron vapor as it passes by, causing liquid boron droplets to form. These droplets combine with the nitrogen to self-assemble into BNNTs.

Researchers used the PVC method to produce the first high-quality BNNTs that are long enough to be spun into macroscopic yarn, in this case centimeters long. A cotton-like mass of nanotubes was finger-twisted into a yarn about one millimeter wide, indicating that the nanotubes themselves are about one millimeter long.

Size of the EMC effect vs. average nuclear density.

Fibrils of boron-nitride nanotubes are formed through the pressurized vapor/condenser method. The nanotube fibrils are produced when the FEL laser beam strikes a target of pressed boron powder. The number indicates laser power level in arbitrary units; about 1.5 kW in actuality. The target rotates to distribute the laser heat evenly.
(click image to view the video)

“They’re big and fluffy, textile-like,” said Kevin Jordan, a staff electrical engineer at Jefferson Lab. “This means that you can use commercial textile manufacturing and handling techniques to blend them into things like body armor and solar cells and other applications.”

Transmission electron microscope images show that the nanotubes are very narrow, averaging a few microns in diameter. TEM images also revealed that the BNNTs tended to be few-walled, most commonly with two-five walls, although single-wall nanotubes were also present. Each wall is a layer of material, and fewer-walled nanotubes are the most sought after.

The researchers say the next step is to test the properties of the new boron-nitride nanotubes to determine the best potential uses for the new material. They are also attempting to improve and scale up the production process.

“Theory says these nanotubes have energy applications, medical applications and, obviously, aerospace applications,” said Jordan.

Smith agreed, “Some of these things are going to be dead ends and some are going to be worth pursuing, but we won’t know until we get material in people’s hands.”

The research will be published in the December 16 issue of the journal Nanotechnology. The article is available for a short time online. It will also be presented at the 2009 Materials Research Society Fall Meeting on December 3.

The research was supported by the NASA Langley Creativity and Innovation Program, the NASA Subsonic Fixed Wing program, DOE’s Jefferson Lab and the Commonwealth of Virginia. The experiments were hosted at Jefferson Lab.

November 10, 2009

Carbon nanotubes are the wiring of the future

Filed under: et.al. — Tags: , , , , — David Kirkpatrick @ 3:16 pm

Previously I’ve blogged about carbon nanotubes replacing copper wiring, and here’s news of a new manufacturing technique that gets that idea closer to the mainstream. This shift in wiring is most likely a “when” instead of an “if.”

From the second link:

A new method for assembling carbon nanotubes has been used to create fibers hundreds of meters long. Individual carbon nanotubes are strong, lightweight, and electrically conductive, and could be valuable as, among other things, electrical transmission wires. But aligning masses of the nanotubes into well-ordered materials such as fibers has proven challenging at a scale suitable for manufacturing. By processing carbon nanotubes in a solution called a superacid, researchers at Rice University have made long fibers that might be used as lightweight, efficient wires for the electrical grid or as the basis of structural materials and conductive textiles.

Others have made carbon-nanotube fibers by pulling the tubes from solid hair-like arrays or by spinning them like wool as they emerge from a chemical reactor. The problem with starting from a solid, says Rice chemical engineering professor Matteo Pasquali, is that “the alignment is not spectacular, and these methods are difficult to scale up.” The better aligned and ordered the individual nanotubes in a larger structure, the better the collective structure’s electrical and mechanical properties. Using the Rice methods, well-aligned nanotube fibers can be made on a large scale, shot out from a nozzle similar to a showerhead.

The late Nobel laureate Richard Smalley started the Rice project in 2001. Smalley knew solution-processing would be a good way to assemble nanotube fibers and films because of nanotubes’ shape. Carbon nanotubes are much longer than they are wide, so when they’re in a flowing solution, they line up like logs floating down a river. But carbon nanotubes aren’t soluble in conventional solvents. The Rice group laid the foundations for liquid processing of the nanotubes five years ago, when they discovered that sulfuric acid brings the nanotubes into solution by coating their surfaces with positively charged ions.


Nanotube fiber: This fiber, which is about 40 micrometers in diameter, is made up of carbon nanotubes.
Credit: Rice University

November 25, 2008

Elmarco named November 08 Autodesk inventor of the month

Filed under: Business, et.al., Science, Technology — Tags: , , , , , , — David Kirkpatrick @ 1:31 pm

A release from this morning:

Nanotechnology Pioneer Shortens Concept-to-Manufacturing Process With Autodesk Digital Prototyping

Autodesk Names Elmarco as Inventor of the Month for November 2008

SAN RAFAEL, Calif., Nov. 25 /PRNewswire-FirstCall/ — Autodesk (NASDAQ: ADSK) has named Elmarco Ltd. (Elmarco), a Czech-based manufacturer of industrial machines for the production of nanofibers, Inventor of the Month for November 2008.

Elmarco relied on Autodesk Inventor software to develop its Nanospider line of machines, which make the production of nanofiber textiles possible on an industrial scale. Nanofiber textiles are highly breathable but have pore sizes that are small enough to prevent micro particles, bacteria or even viruses from passing through, making it ideal for air filtration systems in medical settings or in chip fabrication plants.

The Inventor of the Month program recognizes the most innovative design and engineering advancements made by the extensive community using Autodesk Inventor software–the foundation of the Autodesk solution for Digital Prototyping. A digital prototype allows users to design, visualize and simulate a product before it is built, reducing the reliance on constructing multiple physical prototypes.

“Inventor of the Month Elmarco is the first–and only–company in the world to offer customers machines for the industrial production of nanofibers,” said Robert “Buzz” Kross, senior vice president of Autodesk Manufacturing Solutions. “Inventor has helped Elmarco unleash its innovation in the nanofiber industry.”

Many times smaller than a human hair, nanofibers have a diameter of 200 to 500 billionths of a meter. The Nanospider machine produces these nanofibers through a patented electrospinning process, in which a rotating drum is partially submerged in a polymer solution and placed in a high-intensity electrostatic field. The resulting nanofibers are highly desirable for filtration and acoustic applications.

Simplifying with Digital Prototyping

Autodesk Inventor played a key role in helping Elmarco simplify the concept-to-manufacturing process of the Nanospider machines that mass-produce these nanofibers. The 12-member Elmarco design team uses Inventor to create 3D models of the spinning units and the overall machine body that it can easily share with other members of the organization, or reuse for later designs.

“Autodesk Inventor is easy to learn and very user friendly,” said Jan Cmelik, chief designer at Elmarco. “By leveraging its capabilities, we’re able to reuse existing designs for approximately 80 percent of the parts on our industrial production line.”

For the remaining 20 percent of the parts that must be custom developed–such as chemical distribution vehicles–Elmarco is able to take advantage of the powerful piping and tubing functionality in Inventor software, which helps pipe runs comply with design standards. Streamlining the process further, models of purchased components can be easily imported into Inventor to complete the final assembly. Because the Autodesk solution for Digital Prototyping employs a single digital model through all stages of production, it allows Elmarco to use Inventor software’s visualization tools to give demonstrations of the machine to customers, decreasing review times and improving Elmarco customers’ understanding of the design.

About the Autodesk Inventor of the Month Program

Each month, Autodesk selects an Inventor of the Month from the more than 700,000 users of Autodesk Inventor software, the foundation for Digital Prototyping. Winners are chosen for engineering excellence and groundbreaking innovation. For more information about Autodesk Inventor of the Month, contact us at IOM@autodesk.com.

About Elmarco Ltd.

Elmarco Ltd. is a leading producer of high-tech solutions for the nanofiber industry. Founded in 2000, Elmarco is headquartered in the Czech Republic and has annual revenues of US$23.3 million. For more information about Elmarco, visit www.elmarco.com.

About Autodesk

Autodesk, Inc., is the world leader in 2D and 3D design software for the manufacturing, construction, and media and entertainment markets. Since its introduction of AutoCAD software in 1982, Autodesk has developed the broadest portfolio of state-of-the-art Digital Prototyping solutions to help customers experience their ideas before they are built. Fortune 1000 companies rely on Autodesk for the tools to visualize, simulate and analyze real-world performance early in the design process to save time and money, enhance quality and foster innovation. For additional information about Autodesk, visit www.autodesk.com.

Autodesk, AutoCAD, Autodesk Inventor and Inventor are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names or trademarks belong to their respective holders. Autodesk reserves the right to alter product offerings and specifications at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document.

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