Human Motions Could Soon Power Smartphones, Wearable Devices

Engineering researchers from the Michigan State University have developed a pioneering nanotechnology that may soon power up smartphones and wearable devices using simple human motions, such as walking and swiping.

The new nanotechnology, described in a paper published in the journal Nano Energy, was able to successfully operate an LCD touch screen, a bank of 20 LED lights and a flexible keyboard with the help of simple touching and pressing motions, even without the aid of a battery.

"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, in a press release. "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."

Dubbed as biocompatible ferroelectret nanogenerator or FENG, the new device is as thin as a sheet of paper and can be molded to adapt to many applications and sizes. The researchers noted that the film-like nanogenerator is a low-cost device that becomes more powerful and efficient when folded.

The innovative device is consisted of a silicone wafer fabricated with several thin layers that include silver, polyimide and polypropylene ferroelectret. These layers are all environmentally friendly. Ions were added to each layer, making the device contain charged particles. FENG produces electrical energy when human motions or mechanical energy compresses the layers.

Due to the ability of FENG to become more powerful when folded, the researchers noted that it can start as a large device then be folded again and again to make a smaller more powerful device. Each fold is said to exponentially increase the amount of voltage the device can create. Furthermore, FENG is considered to be "a promising and alternative method in the field of mechanical-energy harvesting" due to its many advantages, such as being lightweight, flexible, biocompatible, scalable, low-cost and robust.