Finger Swipe-Powered Phone? We're 1 Step Closer

Michigan State University scientists have created a new way to harvest energy from human motion, using a thin, non-toxic device that can be folded to create more power

Credit: MSU

The groundbreaking findings, published in the journal Nano Energy, suggest “we’re on the path toward wearable devices powered by human motion,” said Nelson Sepulveda, associate professor of electrical and computer engineering and lead investigator of the project.

“What I foresee, relatively soon, is the capability of not having to charge your cell phone for an entire week, for example, because that energy will be produced by your movement,” said Sepulveda, whose research is funded by the National Science Foundation.

The innovative process starts with a silicone wafer, which is then fabricated with several layers, or thin sheets, of environmentally friendly substances including silver, polyimide and polypropylene ferroelectret. Ions are added so that each layer in the device contains charged particles. Electrical energy is created when the device is compressed by human motion, or mechanical energy.

The completed device is called a biocompatible ferroelectret nanogenerator, or FENG. The device is as thin as a sheet of paper and can be adapted to many applications and sizes. The device used to power the LED lights was palm-sized, for example, while the device used to power the touch screen was as small as a finger.

The press of a palm creates the energy to activate these 20 LED lights, thanks to a groundbreaking new way to harvest energy from human motion created by Michigan State University’s Nelson Sepulveda and his team of engineering researchers.

Advantages such as being lightweight, flexible, biocompatible, scalable, low-cost and robust could make FENG “a promising and alternative method in the field of mechanical-energy harvesting” for many autonomous electronics such as wireless headsets, cell phones and other touch-screen devices, the study says.

Remarkably, the device also becomes more powerful when folded.

This LCD touch-screen contains no battery, but it does contain an innovative device created by Michigan State University engineers that allows it to harvest the energy created by the touch of a finger.

“Each time you fold it you are increasing exponentially the amount of voltage you are creating,” Sepulveda said. “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.”

Sepulveda and his team are developing technology that would transmit the power generated from the heel strike to, say, a wireless headset.
Contacts and sources:
Nelson Sepulveda

Andy Henion
Michigan State University