Researchers at Michigan State University have developed a way to harvest energy from human motion using a nanogenerator to power a smartphone.
The engineers involved in the project were able to successfully operate an LCD touchscreen, a bank of 20 light emitting diode (LED) lights and a flexible keyboard by simply touching or pressing motion and without the use of a battery.
They started with a silicone wafer that was fabricated with several layers of substances such as silver, polyimide and polypropylene ferroelectret. Ions were then added to each layer in the device containing charged particles and energy was created by compressing the device through mechanical energy, or human motion.
[insert finger here]”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 Nelson Sepulveda, associate professor of electrical and computer engineering at Michigan State.
The completed device is called a biocompatible ferroelectret nanogenerator (FENG) and is as thin as a sheet of paper and can be adapted to various sizes for various applications. The researchers used a palm-sized FENG to power the LED lights while the touchscreen was powered by a device as small as a finger.
Michigan State says this low-cost FENG with lightweight and flexible properties could allow mechanical energy harvesting for autonomous electronics such as wireless headsets, smartphones and other touchscreen devices. It could also usher in a host of new form factors for these devices as the FENG becomes more powerful when folded, according to researchers.
“Each time you fold it you are increasing exponentially the amount of voltage you are creating,” said Sepulveda. “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.”