The thread is about the thickness of a human hair, but has the conductivity of metal and the strength of carbon fiber. A promising material for smart clothing and other digital textiles.
The best way to appreciate the remarkable properties of Rice’s nanotube thread is to watch the video below. At around the 0:45 mark you can see an LED lamp that’s being suspended, and powered, by the thread.
We have long known about the remarkable properties of carbon nanotubes (CNTs) — they’re among the strongest and most conductive materials known to man. Up until now, though, it has proven very, very hard to produce high-quality, long-length CNTs that retain these superior qualities.
Rice’s breakthrough stems from the fact that the researchers are using a wet method to produce the CNT thread. While almost every other research group uses a dry method to create bulk CNTs — usually chemical vapor deposition — Rice uses a “wet spinning” method that it pioneered back in 2003. Wet spinning is basically what it sounds like: Clumps of nanotubes are dissolved in a bath of chlorosulfonic acid, and then squirted through small holes to create long strands of CNTs. These long strands — which can be hundreds of meters in length — are then wound onto a big spool to dry out.
It just so happens that Rice’s method of producing CNT thread is very similar to how aramid fibers, such as Kevlar, are produced. Teijin, an Israeli company that produces a material similar to Kevlar called Twaron, supported Rice University with this research. While it hasn’t yet been confirmed, there is a strong chance that Rice and Teijin will be able to use existing equipment and expertise to mass-produce this CNT yarn — and that’s a very exciting prospect indeed.
All told, these long nanotube threads have comparable electrical conductivity to copper, gold, and aluminium alloy — but its thermal conductivity is best-in-class and its tensile strength is four times that of aluminium alloy, or more than 20 times that of copper. Because copper is so weak, copper wires must be fairly thick to withstand manufacturing processes. At its most basic, thin CNT thread could be used in the place of these thick copper wires, resulting in svelter data cables, and perhaps a minimization of some consumer electronics devices too.
Perhaps more important, though, is that this thread is exactly what we need to create smart clothes — clothing with built-in sensors and computers. Rice’s nanotube thread is strong enough and conductive enough that it could be woven into your sweater or jacket. While we’re still some way away from flexible computers, we’re very close to wearable sensors — and, anyway, if you need a computer, it wouldn’t be hard to connect your smartpants to your smartphone.