Category: Nanodot

RobertBradbury writes "The Univ. of Michigan has announced the ability to do nanoscale milling (down to 20nm) using ultra-short laser pulses. Interestingly according to the abstract they aren't exactly sure how it works. This is a new approach to top-down nanotechnology (lithography is also top-down and is currently pushing towards 70nm). In contrast biotechnology, mechanosynthesis and complex chemical methods can be considered bottom-up methods. From a size scale perspective 20nm is slightly smaller than a ribosome and roughly the diameter of Eric's nanomanipulator arm described in Nanosystems (Figure 13.11). So a top-down milling machine methodology might allow the production of a scaled-up nanomanipulator arm which in turn could be used to produce increasingly smaller versions of itself."

WillWare writes "Nature reports that Alan Windle and colleagues at the University of Cambridge, UK, have created unusually long nanotubes. "The team mix ethanol ó the carbon source ó with a catalyst called ferrocene and another chemical called thiophene that helps the threads to assemble. The mixture is squirted into a hot furnace in a jet of hydrogen gas. Nanotubes form as a tangled mass, rather like candyfloss, and are then wound onto a spindle to form strands… So far, the fibres aren't outstandingly strong ó 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.""