Boffins get their circuits in a twist
Stretchy, bendy wires promise flexible electronics
A Baltimore research team has developed a technique for building electrical circuitry that can bend and stretch like rubber. It could be used to make artificial nerves, rubbery needles or wearable electronics.
The researchers used extremely thin gold wire, bent into a wave-like pattern, according to Nature. Thinner wires broke less than thicker ones, so the team sent the current along several parallel wires, each 20 times thinner than a human hair. They found that the spring-like characteristics of this arrangement could cope with levels of twisting or stretching that would destroy normal circuits.
Previously, stretchable conductors have been made by embedding metal particles in a stretchy material. This is of limited use, however, since once the material is stretched, the particles separate at the cost of conductivity. This time, the team made the wires by electroplating gold onto a sheet of silver, surrounding the gold with a stretchy polymer and then stripping the silver away.
Christopher Chen at Johns Hopkins University, Baltimore, says he can imagine plenty of applications for the technique.
For example, surgeons could attach flexible electrodes to a beating heart to monitor for emerging problems. Bendy wires could be used to make rubbery needles that would be safer and more reliable in the treatment of Parkinsons disease, where doctors insert probes into the sufferer's brain. Wiring like this might also find a place in sports kit which monitors its wearer's performance.
Chen told Nature: "We joke about making electrical devices that you can throw against a wall: instead of breaking they would bounce back at you. But we have no idea if that is possible." ®