Flexible Battery Stretches Possibilities for Electronics
A new, ultra-stretchy battery could be used to power bionic eyes, robotic skins, and other biological implants.
CREDIT: Yonggang Huang
What if the batteries on a pacemaker could be recharged without worrisome cords or the need for surgery? The latest in electronics, a flexible battery that can be recharged wirelessly, could make such advancements possible in the near future.
Northwestern University’s Yonggang Huang and John Rogers, of the University of Illinois, recently demonstrated a stretchable lithium-ion battery that they say can be used anywhere, including inside the human body.
Implantable electronics, the researchers believe, might be used to monitor anything from brain waves to heart activity and could succeed where devices that require flat, rigid batteries fail.
Huang said the component parts of the battery are placed side by side in a very small space and then connected with long, wavy wires.
“These wires provide the flexibility,” Huang said. “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.”
The small, high-powered battery has a similar voltage to conventional lithium-ion batteries of the same size. But these new batteries use a design technique known as “ordered unraveling” to stretch up to 300 percent of their original size.
The long, wavy wires used to connect the component parts of the battery can be stretched tightly, until the wires between electrodes become taut. This “ordered unraveling” gives the new battery its noteworthy flexibility.
With room for inductive coils built into the design, the battery can also be recharged from an external source without the use of a power cord. This wireless capability makes the new battery, as well as its corresponding electronic hosts, ideal for use in medical implants and other devices that are difficult to charge using traditional methods.