Everlasting Power

by Caroline Williams New Scientist, 25 Mar 2006 "It looked like a slug moving along the lab bench," says Jeffrey Cheung, a materials scientist at Rockwell Scientific in Los Angeles. "My first reaction was -- oh my goodness someone forgot to turn off the sprinkler outside, and this thing has crawled into the lab. The strange thing was, when I moved to the right or the left, it always followed my movements." Then he leaned over to take a closer look. To his surprise, the slug shot off the workbench and rocketed straight at his midriff. That day, Cheung had been doing some experiments using a commercial ferrofluid. As fate would have it, he made two crucial errors. First he lost a bar magnet, which he had borrowed from a colleague for the experiment. Then he spilt a beakerful of the fluid over his lab bench, leaving it covered with a thick layer of reddish-brown goo. Read more