Embedded electronic implants have long been confined to the realm of science fiction, but the development of a new stretchable battery could soon make them a reality. A pair of scientists have developed a new type of lithium-ion battery that can stretch up to three times its original length and can be recharged wirelessly. The new battery, which is being developed by Northwestern University’s Yonggang Huang and the University of Illinois’ John A. Rogers, could signal a major breakthrough for electronics that can be implanted in the human body, like bionic eyes and heart monitors.
Scientists have developed flexible batteries in the past, but none of them are as stretchable as Huang’s – and they couldn’t be recharged wirelessly. The battery is just as powerful as a standard lithium-ion battery of a comparable size, the only difference being that Huang’s and Rogers’ new battery can stretch up to 300 percent its original size. The researchers expect that the new batteries could be used to power wearable technology and bionic implants.
Huang and his colleagues embedded tiny lithium-ion batteries in a highly flexible silicone sheet. They used a network of metal wires that are arranged in a repeating “S” shape; within the large “S” there are smaller “S’s”, which stretch out and interconnect when the sheet is stretched. “We start with a lot of battery components side by side in a very small space, and we connect them with tightly packed, long wavy lines,” said Huang in a press release. “These wires provide the flexibility. When we stretch the battery, the wavy interconnecting lines unfurl, much like yarn unspooling. And we can stretch the device a great deal and still have a working battery.”