smart currents on solids

Images of the killing machine in Terminator 2 came to mind when I first read this press release from the Hong Kong University of Science and Technology. The assassin-robot (right), you will recall, could turn from metal to liquid and back in a split second. That was supposed to be science fiction. It's reality now.

A team of physicists from the university have invented a 'smart' ER fluid, short for electrorheological fluid.

The liquid, which consists of tiny particles dispersed in silicon oil, solidifies instantly when an electric current is applied to it, but reverts to fluid immediately when supply is cut. 'Put your hand in the liquid there, boss. It feels nice.'