Once in a while it’s useful to note when science transitions to technology and when some technologies leave the laboratory and enter production. Nanotechnology has a good track record in this regard. Born in experiments with molecular chemistry, the science of nanotechnology has found many routes into high-tech products. Here’s a recent case in point: fuzzy fiber. If it sounds like a brand name or marketing moniker, that’s because it is. Its real name is Nano Adaptive Hybrid Fabric (NAHF-X, which is actually trademarked), and it was developed about seven years ago by Khalid Lafdi and colleagues at the University of Dayton Research Institute (Ohio, USA). It took seven years from laboratory experiments, to prototypes, to testing samples, to pilot production, and now – full commercial production.
There are many labs working on growing carbon nanotubes (tiny tubes sized less than 1/100,000th of a human hair) on some kind of substrate (a film, or skin, or layer). The idea is to use the many electrical and chemical properties of nanotubes over larger areas, with the substrate acting as fabric to hold things together. These days there are many industries using metal composites because they are light weight but comparatively strong, however it has been difficult for these composites to retain the electrical properties of the original metal. This is something that carbon nanotubes grown on individual carbon fibers can address – a fabric with the lightweight composition but the electrical characteristics of metals. That is, if the fabric can be manufactured in quantities and sizes that are useful for commercial products.
That’s where most of the seven years went for the University of Dayton team – scaling – in developing the processes that allow for uniform, reliable growth of nanotubes on carbon fibers that can then be made into wide fabrics. Their research continually developed manufacturing techniques that improved from individual fibers, to carbon fiber yarn, and finally to engineered textiles. A prototype production plant was built in Dayton, Ohio where 12 inch (30 cm) wide fuzzy fabric was produced in lengths up to 500 feet (152 m). Now, with additional grants from the state of Ohio, the U.S. military and private industry a new full production plant will be built to produce fabric 60 inches (1.5 m) wide.
Fuzzy fabric can easily be incorporated into resin products that can be tailored for electrical and thermal conductivity, with applications in chemical and biological sensing, energy storage and conversion, and thermal management – among many other things. One of the first large-scale uses of fuzzy fiber will be in UAVs (Unmanned Aerial Vehicles, a.k.a. drones) where the conductive ‘skin’ of fuzzy fiber can serve for the plane’s power, sensor, and communications, thereby cutting weight.
You’ll notice the involvement of government, in this case the military, in the funding and application of fuzzy fiber. That’s quite typical. Though there is often a potential for large-scale application in many nanotechnologies, the road to large-scale production is tricky – and expensive. For one thing, the unusual and beneficial properties exhibited by materials at the nano-scale, and usually tested in the laboratory at that same scale, often behave differently when aggregated into larger pieces. There’s a risk in trying to move nanotechnology from lab to factory, a risk that sometimes only government is willing to shoulder.
Lafdi called the material “game-changing” because of its ability to be produced in continuous sheets to desired sizes like other fabrics. “Everybody is growing carbon nanotubes on substrates,” Lafdi said. “We’re the only people who are producing them on a large-scale and continuous process, and not just in batches. This means we can produce the material at a low cost, and it also means we can produce pieces big enough to cover an aircraft.”
[Source: University of Dayton]