It's a tall order: make a material that conducts electricity, stretches like rubber, expands and contracts when hit with electric current, and is clear as glass. There have been many attempts, but they've all fallen short.
Now a Harvard University team has done it by combining a transparent hydrogel with a conductive polymer that behaves like a motor. The work could lead to artificial muscles, transparent loudspeakers and power sources that generate electricity when squeezed or stretched.
The study, led by Zhigang Suo, professor of mechanics and materials, appears in this week's journal Science.
"Suo and his team combined, in a very clever way, two known things," said John Rogers, a materials science professor at the University of Illinois, who has done extensive work on flexible, implantable devices. "The result -- a transparent, artificial muscle -- is something that is new, and potentially important as a technology for noise cancelling windows, haptic display interfaces, tunable optics and others." Rogers was not involved in this study.