Advertisement

Flexible device harvests energy from basic motions -- like a finger swipe

"It may be small enough to put in a specially made heel of your shoe so it creates power each time your heel strikes the ground," said researcher Nelson Sepulveda.

By Brooks Hays

LANSING, Mich., Dec. 9 (UPI) -- Engineers at Michigan State University have developed a flexible, film-like device that turns simple human motion into usable energy.

The movement of a finger across a smartphone screen could soon keep that very device running indefinitely. Keyboards could render power from typing fingers and feed it to laptop batteries; fitness trackers could be powered by the kinetics of jogging feet.

Advertisement

"We're on the path toward wearable devices powered by human motion," lead researcher Nelson Sepulveda, associate professor of electrical and computer engineering at Michigan State, said in a news release.

The device consists of a silicone wafer, the layers of which are interspaced with thin slices of silver, polyimide and polypropylene ferroelectret. The layers are infused with ions. When compressed, the film-like substrate generates electric energy.

Researchers described the new technology -- called a biocompatible ferroelectret nanogenerator, or FENG -- in the journal Nano Energy. The study's authors believe the device's potential is aided by its light weight, simplicity and scalability.

Impressively, the device's power-generating potential doubles each time it is folded.

"Each time you fold it you are increasing exponentially the amount of voltage you are creating," Sepulveda explained. "You can start with a large device, but when you fold it once, and again, and again, it's now much smaller and has more energy. Now it may be small enough to put in a specially made heel of your shoe so it creates power each time your heel strikes the ground."

Advertisement

Sepulveda and his colleagues are now working on technology to wirelessly transfer energy generated from the power device to wearable technologies -- from the heel of a running shoes to headphones or fitness tracker, for example.

Latest Headlines