The material can be turned from liquid to solid (or vice versa) in 1/10th of a second, the group reports online 5 October in Nature Materials. The researchers measured the material’s strength by electrifying it between two parallel plates, which they either pulled apart or slid past each other with increasing force. The new material increases in strength with the applied field, up to the strength of hard rubber, they found. Some electric smart fluids get nearly as hard, but only at high pressure. The urea coating is key to the enhanced effect, the researchers say.

“This does suggest a new route to [smart electric] fluids that may have useful properties,” says John Ginder, a physicist in Research and Advanced Engineering at Ford Motor Co. But he adds that the material would have to withstand even higher sheer to survive in clutches or shock absorbers. Bill Bullough, an independent engineer and consultant at the University of Sheffield, U.K., says he has performed such tests on the fluid “and it does work well. It’s a big improvement.”