The liquid-metal antenna could also "heal" itself when damaged. When exposed to air, the alloy forms a thin oxidized coat that keeps it from flowing freely. Knowing this, Dickey cut through the antenna with a razor blade to test its ability to heal. The oxide layer kept the liquid metal within the PDMS, and once the razor was removed, in many cases the two ends spontaneously reformed a single, conducting wire. In the other instances, the researchers had to press the severed ends together to reestablish a connection.

Dickey says that it would be easy to mass-produce this kind of antenna: a whole sheet of PDMS forms could be made at once and then cut up into individual devices. The researchers are also evaluating other polymers, since PDMS might interfere with the efficiency of some forms of antennas, such as the loops, helices, or patches used more commonly in communications devices such as cell phones and radio or TV transceivers. In addition, Dickey says, other polymers could allow the antennas to stretch even further than PDMS before tearing apart.

Researchers who are developing flexible electronics are interested in the possibilities opened up by the new antenna. "It's a really clever way to address an important problem," say John Rogers, an engineering professor at the University of Illinois at Urabana-Champaign who is developing soft materials for flexible and stretchable electronics.

Juan Hinestroza, an assistant professor of fiber science at Cornell University, raises the idea of incorporating Bluetooth or cell-phone antennas into clothing. "Because of the flexibility, there will be negligible effects on the draping properties of the material, and the antenna can go unnoticed to the observers and the wearer," he says.