Author: Stephen Ornes / Source: Science News for Students
Inspiration often comes from unusual sources. Nelson Sepúlveda knows this firsthand. He got his big idea for a new source of power simply by looking out the window at the right time.
Sepúlveda is an engineer at Michigan State University in East Lansing. He studies materials that can be used to build tiny electronic devices. Those devices need power. But Sepúlveda doesn’t want to power them with batteries, which are bulky and wear out. He wanted to find something better.
In 2012, he realized one such power source was closer than he’d imagined. He had been discussing his research with a group of scientists. During the meeting, he looked out the window as a student ran by, wearing headphones. Her arms and legs swung back and forth. This jogger’s feet rose and struck the ground, up and down, again and again.
Suddenly it dawned on Sepúlveda: “There’s a lot of energy in that movement that’s not being used.”
He was looking at mechanical energy, the type associated with movement. It’s plentiful in every jogger — and every pedestrian. With that glance out the window, the engineer pictured a plentiful and renewable energy source. One day, he mused, that jogger’s movements could generate electricity to power the device connected to her headphones. But first, he realized, he’d need “to find ways to harvest this energy.”
Fast forward a few years. Sepúlveda’s vision is now much closer to reality.
In December 2016, his research team introduced a keyboard that generates an electric current as it is squished or expanded. It also can pull small bits of energy from the motion of each keystroke. If the material he used was adapted to be the screen on a smartphone, a swipe across it could help power the phone. A flexible computer screen, when folded up and placed in a shoe, could later charge as someone walks.
The possible uses for such technologies are limitless, muses Sepúlveda.
Last year, his group showed how a similar device could work as a portable, sheet-like speaker — one you might use to play music. But until it’s needed, the user could just fold it up and store it in a pocket.
Sepúlveda is one of many researchers building devices to turn everyday movements into abundant energy without making pollution. Nano means “tiny.” A generator is a machine that produces electric current. His nanogenerators aren’t really tiny. They just make electricity using tiny particles.
Researchers are inventing more and more creative ways to capture energy from our everyday motions. Some have created devices that can be installed in shoes, clothing and other items that people wear. Others have found ways to capture energy from motions such as falling rain, evaporating water or the rotating tires of a moving car. And on July 20, university researchers in Pennsylvania and Utah unveiled an energy harvester that can be worn like a watch. Walking or jogging while wearing it could generate enough power to run a small device. What type? It might power something to monitor someone’s health, according to Susan Trolier-McKinstry. She’s a co-developer and engineer at Pennsylvania State University in University Park.
Any movement is a potential source of energy, says Xing Fan. He is a mechanical engineer at Chongqing University in China. He helped develop a fabric that can capture some of this wasted energy. Special threads within it conduct electricity. Shirts made from such a material could generate power from the natural activity of whoever wears it.
“You move your body every day,” Fan says. So there’s no limit to the amount of mechanical energy available. The tricky part, he concedes, is figuring out how to get your devices to use it.
A recipe for electricity
Indeed, the challenge for researchers like Fan and Sepúlveda is figuring out how to translate — change — that energy into a form that devices recognize and can use.
The body stores and uses mechanical energy. Devices use a different form of energy: electricity. How do you transform one to the other?
You can…
The post What powers these electronics? We do! appeared first on FeedBox.