The World's Longest Carbon Nanotube
Roland Piquepaille writes "As you probably know, carbon nanotubes have very interesting mechanical, electrical and optical properties. The problem, currently, is that they're too small (relatively speaking) to be of much use. Now, researchers at the University of Cincinnati (UC) have developed a process to build extremely long aligned carbon nanotube arrays. They've been able to produce 18-mm-long carbon nanotubes which might be spun into nanofibers. Such electrically conductive fibers could one day replace copper wires. The researchers say their nanofibers could be used for applications such as nanomedicine, aerospace and electronics."
That puts it in the area of useable length for macro-sized application.
Although the PR person who wrote this obviously thinks this is a major breakthrough, these guys are using a method which was originally invented by Japanese researchers three years ago (google for "CNT super growth"). The Japanese guys have since focused on getting the fastest growth rate possible (I think it's about 0.2mm/min... if you want to figure out how many, many years it would take to grow a space elevator). There are lots of people working on improving this growth method, 18mm arrays may be the longest, but it seems to be in the same range as other people working on the "super growth" method. That doesn't diminish this research, rather it means that this method is very likely to work in the long run for industrial scale growth of nanotubes for materials (more simply, it's easily reproducible, and people want "nano-enhanced" golf clubs).
Isolated nanotubes have been grown longer than this (I've grown isolated nanotubes longer than this, and I'm not a growth specialist), as have bundles of nanotubes. This is the longest array of pure, aligned, continuous nanotubes.
From wikipedia.