Alan Windle and his team of researchers at the University of Cambridge have set a new record for length of produced carbon nanotube fibers.
A thread of carbon nanotubes more than 100 metres long has been pulled from a fiery furnace. The previous record holder was a mere 30 centimetres long.
"This is ground-breaking research - but it's early days" says Harry Swan, whose company Thomas Swan of Consett, UK, is helping to finance the development of the new manufacturing technique.
So far, the fibres aren't outstandingly strong — they're no better than typical textile fibres. But Windle thinks that there's still plenty of scope for improving the process to make stronger fibres, for example by finding ways to make the nanotubes line up better. In Kevlar it's the good alignment of molecules that generates the high strength.
If Windle's group can improve the strength of the fibers produced by this approach then nanotube fibers could finally move into use in industrial applications. The potential exists to lower the cost of cars, aircraft, trains, suspension bridges, an a large assortment of other vehicles and stationary structures. Work on making nanotube strands line up better to increase their strength is also showing signs of making progress. If carbon nanotube fibers ever achieve sufficient strength (and lots of scientists believe they can) then construction of a space elevator becomes possible. That would lower the cost of getting into space by 2 or 3 orders of magnitude.
One of the biggest obstacles in the use of nanotechnology is the cost of manufacture. Scientists working in labs come up with all sorts of interesting nanomaterials that have qualities superior to existing materials for many applications. These discoveries regularly receive glowing media reports. But too many such discoveries are going unused because of a lack of ways to make these nanomaterials cheaply in bulk. Nanotubes are a great example. They are considered to have enormous promise but in spite of the interest they have attracted no team has found a cheap way to make them. Therefore reports of nanotech production cost reduction advances are important.
UCLA chemists report in the Feb. 28 issue of Science a room-temperature chemical method for producing a new form of carbon called carbon nanoscrolls. Nanoscrolls are closely related to the much touted carbon nanotubes -- which may have numerous industrial applications -- but have significant advantages over them, said Lisa Viculis and Julia Mack, the lead authors of the Science article and graduate students in the laboratory of Richard B. Kaner, UCLA professor of chemistry and biochemistry.
"If nanotubes can live up to all their predicted promise, then we believe that we have a method for making analogous materials for a fraction of the cost," Mack said.
Nanotubes are pure carbon sheets in a tubular form, capped at each end. Viculis and Mack's carbon nanoscrolls are also pure carbon but the sheets are curled up, without the caps on the ends, potentially allowing access to significant additional surface area. While nanotubes are normally made at high temperatures, nanoscrolls can be produced at room temperature.
"Our method involves scrolling sheets of graphite, which could give us a much higher surface area," Viculis said.
"If we can access the entire surface area on both sides of the carbon sheets -- unlike with carbon nanotubes, where only the outside surface is accessible -- then we could adsorb twice the amount of hydrogen -- an enormous increase," Mack said, "improving on hydrogen storage for fuel (an alternative to fossil fuels)."
"Nanoscrolls can be made by a relatively inexpensive and scalable process at low temperatures," Mack said. "Our starting materials are just graphite and potassium metal. The idea is beautiful in its simplicity."
"Carbon surfaces are known to adsorb hydrogen. A difficulty with using hydrogen as a fuel source for cars, instead of gas, is obtaining a material capable of storing enough hydrogen to make the approach feasible," Viculis said.
"Carbon nanoscrolls could make pollution-free, hydrogen-powered cars better than they would otherwise be," said Kaner, the third co-author on the Science paper. "This research is a good start. We have a long way to go. For this approach to work well, we need to get down to individual carbon layers, and we are not there yet. On average, the nanoscrolls are 40 layers thick. We have not yet realized the full surface area or all the properties we are after. The challenge is to reduce the nanoscrolls to individual layers. We have many good leads, and have started new collaborations."
The research may lead to numerous applications.
"For electronic applications, nanotubes may work well," Kaner said. "For applications where high surface area is important -- such as hydrogen storage, or energy storage in super-capacitors -- these nanoscrolls may be better."
Other possible applications for nanoscrolls, Kaner said, include lightweight but strong materials for planes and cars, and improved graphite-based tennis rackets and golf clubs.
The use of nanoscrolls for energy storage is especially interesting. Liquifying hydrogen requires considerable energy expenditure to cool it and also requires extremely well insulated tanks to hold it. But gaseous hydrogen takes up too much space. If nanoscrolls could be used either to store hydrogen densely at room temperature or to make a better kind of battery then they'd be very attractive.
The MIT Institute for Soldier Nanotechnologies will offically open April 2003.
Researchers are working to develop sensor patches and reactive coating that could respond to chemical and biological agents with antidotes or determine whether a soldier is dehydrated and adjust accordingly. They are trying to make soft materials rigid, to recycle water from a soldier's body, and to create "intelligent" fabric by weaving computer and communications technology into a uniform.
See a previous post for more details on this project.
The US Army is funding the MIT Institute for Soldier Nanotechnologies (ISN) to develop all the supersoldier gadgets that Hollywood shows in movies.
Jan. 6, 2002 – In the not-too-distant future, American soldiers may wear Kevlar vests that will protect against biological agents as well as stop bullets. With the flick of a switch, the sleeves of their uniform may stiffen into anti-shrapnel armor or a medical splint. They may carry night-vision contacts lenses, while a patch on their shoulder or helmet signals their position to their commander.
The article doesn't name the type of material that comes incredibly stiff when a magnetic field is applied but they are probably referring to magneto-rheological fluids.
Interesting excerpts from the MIT ISN web site FAQ answers:
The ISN’s role is one of basic and applied research. The primary goal is to create an expansive array of innovations in nanoscience and nanotechnology in a variety of survivability-related areas that will be harvested by the industrial partners for future Army application. The research will integrate a wide range of functions, including multithreat protection against ballistics, sensory attack, chemical and biological agents; climate control (cooling, heating, and insulating), possible chameleon-like garments; biomedical monitoring; and load management. The objective is to enable a revolutionary advance in soldier survivability through the development of novel materials for integration into the future warrior systems.
The focus of the ISN is soldier survivability. The intent is to improve the ability of the soldier to perform their mission in the battlespace where somebody is actively trying to locate and kill them. The first of the research areas, listed above, looks at both ballistic and directed energy protection of the soldier. Mechanically Active Materials simultaneously looks at mechanical actuators for armour or exoskeletal support (either for load carrying systems or wound compresses and splints), and pressure/motion sensors to monitor the soldier. Signature and Detection Management looks at active camouflage and sensor systems to detect enemy rangefinding or target designation probes. The Soldier Medical Technology thrust focuses attention of soldier triage and automatic "first aid" for a wounded or disabled soldier. The final two areas are crosscutting areas intended to provide enabling technologies for the other thrust areas.
From the results of current DoD sponsored nanoscience research a number of potential applications have been developed. One is a semi-permeable membrane with molecular scale pores that open to allow passage of water but remain closed to other molecules. This would have application to water filtration and purification systems or for chemical/biological protective clothing. Molecular scale rotors on a 3d grid array so that they can pivot and block off high intensity laser light – a molecular scale Venetian blind – to protect soldier eyes from laser blinding or to act as high-speed switches in opto-electronic circuits. Nanoparticles of gold in solution, linked together by strands of DNA that are specifically encoded to respond to the DNA of biological agents, that produce dramatic optical colour changes to allow reliable field detection of biological warfare agents at very low sample sizes, or rapid, reliable screening for such diseases as flu, strep etc. Nanoporous antenna ground planes that reflect all electromagnetic energy with very low absorption, to increase the net transmission power of cell-phones and small radios. Nanoporous electrodes for batteries to increase power density and efficiency – this list grows longer every day.
Super soldiers must be able to leap tall walls with a single bound.
Thomas even spoke of soldiers being able to leap over 20-foot walls by "building up energy storage in shoes." Thomas went on to note that MIT researchers have recently created "world-record actuator materials" that are "better than human muscles."
One of the most intriguing ideas mentioned is to make optical bar codes visible only to one's own troops in order to reduce friendly fire casualties.
On the battlefield or on patrol, soldiers risk being separated from their own troops. They need a way to distinguish their side from the enemy. So scientists at the Massachusetts Institute of Technology’s (MIT) Institute for Soldier Nanotechnologies (in partnership with the U.S. Army) set out to create a fabric that carried an optical bar code, visible only to someone wearing special goggles.
NASA announces the use of genetic engineering to customize a protein to make it more useful for nanostructure construction.
Scientists from NASA's Ames Research Center, Moffett Field, CA, have invented a biological method to make structures that could be used to produce electronics 10 to 100 times smaller than today's components.
As part of their new method, the scientists genetically engineered proteins from "extremophile" microbes to grow onto semiconductor materials.
The microbes' environments are "extreme" to us -- near-boiling, acidic hot springs -- but just right for the biological organisms to grow mesh-like structures, known as "chaperonins," presumably for their accompanying role.
"We took a gene from a single-celled organism, Sulfolobus shibatae, which lives in near-boiling acid mud, and changed the gene to add instructions that describe how to make a protein that sticks to gold or semiconductors," said Andrew McMillan, a leader of the project.
"What is novel in our work," he continued, "is that we designed this protein so that when it self-assembles into a two-dimensional lattice or template, it also is able to capture metal and semiconductor particles at specific locations on the template surface."
The genetically engineered proteins form lattice-like structures that act as templates, and particles of gold or semiconductor material (cadmium selenide/zinc sulfide) stick to them. According to McMillan, the minute pieces that adhere to the protein lattice are "quantum dots" that are about one to 10 nanometers across. Today's standard computer chips have features that are roughly 130 nanometers apart.
The proteins can be used to make highly patterned structures.
"The cage-like chaperonin provides an ideal structure that we envisioned as being a vessel or container to use to organize nanophase materials," McMillan told nanotechweb.org. "The higher-order crystalline structures that these protein-cages can be induced to form closely resemble similar patterns that the electronics industry uses, namely in the formation of precise, regular arrays of materials on substrates."
Here, we fabricated nanoscale ordered arrays of metal and semiconductor quantum dots by binding preformed nanoparticles onto crystalline protein templates made from genetically engineered hollow double-ring structures called chaperonins. Using structural information as a guide, a thermostable recombinant chaperonin subunit was modified to assemble into chaperonins with either 3 nm or 9 nm apical pores surrounded by chemically reactive thiols.
Eric Smalley in Technology Research News has interviewed other researchers in the field who provide important qualifiers on the usefulness of the research.
Proteins are particularly useful because researchers can modify their structures in precise locations without significantly altering their folding behavior, said Zhang. "This tailor-made approach will have tremendous impact on the growth of nanotechnology and nanobiotechnology," he said. "However, much effort is still needed to reduce the high cost of production and [improve the] stability of proteins in their complexes," said Zhang.
Proteins are obviously going to turn out to be important tools for creating nanostructures. Biotechnology is probably going contribute more to nanotechnology than vice versa for some years to come. A huge number of types of proteins already exist which perform an enormous variety of molecule-level transformations Also, the machinery whereby cells synthesize proteins can be used to make whatever modified and customized proteins look like they might be useful. The techniques exist to change DNA sequences. So customized genes can be used to make customized proteins.
The Economist reports that the venture capitalists are still not pouring a lot of money into nanotechnology
Lured by such large numbers, and always on the look-out for the next big thing, venture capitalists are fervently courting nanotechnologists. But as one pundit put it, so far there are more meetings on investing in nanotechnology than there are serious opportunities to punt. Investors are finding that business plans are often little more than repackaged research-grant proposals. And many of the top “nanotechnology” companies are actually developing more conventional microsystems.
However, industrial concerns which do a lot of business in chemicals and materials are spending a lot of money on nanotech in order to make better products in their traditional product markets. BASF is spending $100 million per year on Nanotech research and development.
The company is also developing a water-repelling and self-cleaning film that mimics the nanoscale features present on the surface of the lotus flower leaf. Any water on the surface beads up and rolls off because of the water – repelling nature of the material. Instead of sliding off the water, the droplet rolls off, collecting dirt particles on its surface as it does so. The film is based on a combination of nanoscale crystals developed using technical waxes and a polymer such as polyethylene or polypropylene.
BASF is also developing nanomaterials to generate different colors in polymers without the use of dyes. The colors are generated by forming a film of ordered nanoscale crystals set at a specific angle to the light. Different uniform particle sizes generate different colors. The crystalline film is composed of a polystyrene core surrounded by a shell of polybutyl acrylate. The film is sprayed onto a surface in liquid form and dries into ordered crystals. Applications could include packaging films, decorative papers, and cosmetic applications, including nail polish and hairspray, BASF says.
For many companies the best path toward further refinement of their products is to work with increasingly smaller materials and to manipulate materials on a smaller scale. The development of nanotech doesn't need venture capital funding in order to happen. A lack venture capital funding might be a sign that most of the obvious next steps in development are already being undertaken by existing companies.
Writing in Prospect Magazine Michael Gross surveys the field of nanotechnology and points out a surprising (at least to me) widely available use of nanotechnology:
The first nanotechnology breakthrough outside the information technology market is the microfabricated impact sensor to trigger airbags in cars. The new kind of sensor is based on a Mems (micro-electromechanical system) device, which means that it is fabricated by the same kind of technology as a computer chip, only that its function is mainly mechanical rather than electronic. When it was introduced in 1995, it turned out to be not only smaller and more efficient than the sensors previously available, but also 100 times cheaper. Understandably, it took over the world market in a matter of months.
But how about products designed from molecules upwards? There is at least one that you can buy already. It is the self-cleaning window. It uses a combination of two clever molecular tricks. First, it contains a catalyst that uses the energy of light to oxidise common kinds of dirt, to convert them into smaller, more soluble molecules that wash away with rain water. At this point, the second trick comes in. Ordinary glass is fairly water-repellent (hydrophobic), which means that water does not cover it smoothly, but tends to form droplets. The surface of self-cleaning glass, however, is coated in molecules that attract water and encourage it to spread out. So, instead of sitting around as drops which leave drying spots when they evaporate, the rain will cover the surface evenly, dissolve what the photocatalyst made of the dirt, and run off. Simple. Yet it would not be possible without molecular design on the nanometre scale.
Do you all remember the Star Trek episode "Is There No Truth In Beauty" in the original series with Diana Muldaur as the blind Miranda Jones who wore a cape over her that served as a sensor net that allowed her to see? Real life is starting to catch up with science fiction:
The aim of STRETCH (not an acronym) is to develop large e-textile fabrics that will look like typical military equipment, such as tents or camouflage nets. The electronic wires and sensors woven into the fabric will perform the complex procedure of listening for the faint sounds of distant vehicles being deployed by the enemy.
Within the fabric, the sensors and their connecting wires will communicate with one another to create patterns of information. This information can then be translated by computer software into images that will enable soldiers to determine the location of detected sounds.
"We're designing and constructing a 30-foot-long prototype for the STRETCH fabric," Jones said. "The goal of the project is to develop a low-cost, flexibly deployable e-textile system that has low power requirements and doesn't rely on radio waves." The Virginia Tech and ISI researchers plan to test the prototype in November.
The military already has sound detection systems that rely on radio waves, but communication via radio waves can alert an adversary to a military unit's location. The e-textiles system being developed as part of STRETCH produces no detectable energy and also requires less power than radio-wave-operated systems.
"Cloth has properties that can be useful for certain electronic applications," said Robert Parker, director of ISI and co-principal investigator on the STRETCH project. "We can easily and cheaply make large pieces of cloth, light and strong, that can be stretched over frames into any desired shape."
Sound detection is not the only potential use for the STRETCH e-textile system. Fabrics can be woven with sensors that can detect chemicals, pick up satellite signals, and perform other feats. Jones and his colleagues also foresee numerous industrial uses.
Jones and Martin also have received a $400,000 National Science Foundation Information Technology Research (ITR) grant to design wearable computers made of e-textiles.
The generic concept of wearable computers is a small CPU in a fanny-pack connected to a cumbersome head gear that holds a display screen at eye-level. The Virginia Tech ITR project is something completely different.
Because the wires and sensors in e-textiles are woven into the fabric, wearable computers could be constructed much like normal-looking shirts or hats or other types of cloth apparel. These computers wouldn't connect users to the internet or send and receive e-mail, but would perform specific functions necessary to the wearers.
"Wearable computers constructed of e-textiles offer context awareness," Martin said. "They can be designed to be aware of the user's motions and of his surroundings."
For example, sensors called accelerometers -- which are used to cue airbags to deploy -- can detect changes in speed and direction. There are visual sensors that can project images to tiny displays clipped to eye glasses. An e-textile shirt for a blind user might include tiny vibrating motors that would provide cues about approaching objects.
Of course this opens up some interesting possibilities. These textiles will eventually become very advanced. You could leave your jacket in your chair in a business meeting, step out temporarily, and be able to come back and ask your jacket later what people said while you were gone. Or of you were trying to leave the house and couldn't figure out where you left your jacket you could yell out and ask it where it was. If it was smart enough it could recognize your voice (you'd have to give it a name too in order to call to it) and respond. Plus, you could have an artificially intelligent talking couch. It could warn someone if they were falling asleep with a lit cigarette in their hand: "Wake up you idiot, you're about to burn me!".
There would also be the erotic talking towel that would go ooh and aah as a person toweled off after a shower. Then there'd be the hat that could tell you that someone was coming up on you from behind. Or how about the computer chair that a man's wife might get him that would tell him he's spending too much time in front of the computer and to get out and work on the yard?
The US military is funding the development of nanotech smart coatings might contain switches, gears, and motors that would be used to report problems, do repairs, and even rapidly change appearances:
U.S. Army experts are trying to embed microscopic electromechanical machines in paint that could detect and heal cracks and corrosion in the bodies of combat vehicles, as well as give vehicles the chameleon-like quality of rapidly altering camouflage to blend in with changing operating environments.
Officials of the Army Tank-automotive and Armaments Command's Armament Research, Development and Engineering Center (TACOM-ARDEC) at Picatinny Arsenal, N.J., are working with scientists at the New Jersey Institute of Technology in Newark, N.J., to develop nanotechnology-based "smart" coatings for Army vehicles and other materiel.
If the coatings are going to be that sophisticated it also seems reasonable to expect the coatings will eventually embed sensors as well.
The military might want to consider incorporating some of the ideas that Jonathan Dordick is working on for self cleaning surfaces. The ability of surfaces to kill pathogens on contact would be great for defense against bioweapons:
Nov. 8, 2002 – Detergent manufacturers have long used enzymes in their formulations for fighting really tough dirt. Jonathan Dordick, a chemical engineer at Rensselaer Polytechnic Institute in Troy, N.Y., is taking the battle against dirt a step further, using nanotechnology to design a self-cleaning plastic in which the enzyme molecules are an integral part of the material. When the plastic comes into contact with bacteria or other pathogens, the enzymes attack the microbes and destroy their ability to bind to its surface.
This is even more useful for bioweapons defense than it appears at first glance. If a vehicle has travelled thru an area that has airborne bioweapons in it and if the vehicle is sealed its occupants might be safe. But eventually they have to get out wearing their bioweapons gear and then get back in. Now the inside of the vehicle is contaminated by the outer coatings of their protective suits and they can't take off their suits. The ability of surfaces to self-sanitize would be a great time and life saver.
These developments demonstrate just how different the future will be. Will we need to take our cars to the car washer? Or will we just have to flip a switch and suddenly energy will flow across the surfaces of cars powering nanotech cleaners that will clear off cars in a minute? Or how about self cleaning bathtubs, toilets, sinks and floors? Picture a floor that collects up and moves the dust and dirt in a wave into a corner where a nanotech processor ejects the dirt into an outside receptacle.
Also, will houses of the future still have to be repainted periodically? Or will an underlying nanotech layer create a huge surface network that will transport repair material to wherever a wind blown branch has created a scratch? Will nanotech surfaces in the house also clean the smears off of walls and repair scratches there as well? Will one be able to change the color of the house inside and out just by dialing a switch?
What the article doesn't say is whether this approach can be used to build larger batteries that would have higher power density than existing conventional large batteries. My guess is that the answer is Yes but it is not clear. Anyone know? Prototype devices are expected in 3 years:
All batteries consist of two electrodes, an anode and a cathode, and an electrolyte solution. UF researchers have created both nano-anodes and nano-cathodes, or anodes and cathodes measured on the scale of billionths of a meter. They've shown in tests that these electrodes are as much as 100 times more powerful than traditional ones.
The electrodes also have a unique and promising structure.
"The UF progress is very significant," said Bruce Dunn, a professor of materials science and engineering at the University of California-Los Angeles, the lead institution in the project. "(Martin's) work, the fabrication and testing of nano-dimensional cathodes and anodes, represents the key elements of his concentric tube battery approach, which represents a novel three-dimensional configuration."
Martin and his colleagues create the nano-electrodes using a technique he pioneered called template synthesis. This involves filling millions of tiny "nanoscopic" holes in a centimeter-sized plastic or ceramic template with a solution that contains the chemical components that make up the electrode. After the solution hardens, the researchers remove the template, leaving only the electrodes. The next challenge is to find a way to put together the nano-anode and nano-cathode with a nano-electrolyte and other components.
"We've proposed a totally new design for a battery where all the components are nanomaterials, and we have succeeded in making nearly all of these components," Martin said. "We have not yet developed the technologies to assemble these components, and that's what we're working on."
Robbie Sides, a UF doctoral student in chemistry and one of the researchers in Martin's lab, said UF's nano-anodes and nano-cathodes are not only more powerful than traditional ones, they're also hardier. Lithium-ion battery electrodes might sustain an average of 500 charges and discharges before wearing out, he said. In tests done by another UF chemistry doctoral student on Martin's team, the nano-electrodes sustained as many as 1,400 charges.