Oct 222007

Gizmag reports that researchers at the University of Michigan have used nanoscale fabrication techniques to create a light-weight transparent composite plastic that’s as strong as steel.

The interdisciplinary team of scientists solved a problem that has confounded engineers and scientists for decades: individual nano-size building blocks such as nanotubes, nanosheets and nanorods are ultrastrong, but larger materials made out of bonded nano-size building blocks were comparatively weak – until now. “When you tried to build something you can hold in your arms, scientists had difficulties transferring the strength of individual nanosheets or nanotubes to the entire material,” Engineering professor Nicholas Kotov said. “We’ve demonstrated that one can achieve almost ideal transfer of stress between nanosheets and a polymer matrix.” The researchers created this new composite plastic with a machine they developed that builds materials one nanoscale layer after another. The robotic machine consists of an arm that hovers over a wheel of vials of different liquids. In this case, the arm held a piece of glass about the size of a stick of gum on which it built the new material. The arm dipped the glass into the glue-like polymer solution and then into a liquid that was a dispersion of clay nanosheets. After those layers dried, the process repeated. It took 300 layers of each the glue-like polymer and the clay nanosheets to create a piece of this material as thick as a piece of plastic wrap.

For further info see the U-M website. There’s also an abstract of the article here and an informative discussion by Roland Piquepaille on the topic here.