Pacific Northwest National Laboratory scientists are developing an electrode with lots of surface area to efficiently purify water. This image, taken at the Environmental Molecular Sciences Laboratory, shows what is called polypyrrole conductive polymer-coated carbon nanotubes grown on a carbon fiber. They say that these coated nanotubes could be used as an electrochemically switched ion-exchange electrode for water purification. Conductive polypyrrole is also being investigated for use in fuel cells, sensors and electronics. Larger image available here.