The Energy Scavengers
By harvesting the everyday energy of static electricity, scientists may have found the world’s most plentiful source of renewable, sustainable power.
The plastic gizmo in Zhong Lin Wang’s hand doesn’t look like tomorrow’s solution to our looming energy crisis. It’s about the size and shape of a small grapefruit, but smooth and translucent. As he shakes it, a smaller ball inside bounces around freely.
“If you’re out of power, you’re out of everything,” says Wang, speaking in a fierce whisper that demands listeners lean in. He stands perfectly still, but the shaking makes the interior ball clatter around like a frustrated piece of popcorn. In his other hand, Wang holds a small circuit board with a blinking LED light in the middle. A wire connects the plastic sphere to the light. The more he shakes, the louder the clatter, and the faster the white light blinks on and off.
We’re in a windowless basement room on Georgia Tech’s Atlanta campus. A trio of fresh-faced researchers stand nearby in white lab coats, watching and smiling. One holds a keyboard, and another a piece of red and yellow fabric.
“In our environment, everything is moving, everything is changing,” Wang says, still shaking. “It’s all energy, and so much is wasted.” He wants to do something about that. For the last decade and a half, Wang, an electrical engineer and nanotechnologist, has sought ways to scavenge energy from the movements of ordinary life.
His timing couldn’t be better. The energy problem is big: We need power in large doses to keep our cities lighted and cars running, and we need electricity in small doses — lots of them — to recharge batteries in our phones, fitness trackers and tablets. Those demands have a cost. Last year in the United States, about two-thirds of the total energy demand required burning fossil fuels like coal and natural gas, a process that releases carbon dioxide and other greenhouse gases into the atmosphere, where they’re reshaping the climate.
Renewable power sources, including sun, wind and water, provided another 17 percent or so of total energy demand. But harnessing the forces of nature involves challenges that are formidable — and currently unsolved. Even the bike lights and elliptical machines that convert exercise into electricity need a lot of OOMPH to work.
Instead, Wang is pioneering an engineering effort to generate electricity with a small oomph. Like from footsteps. Or raindrops hitting a car. Or the effort required to press keys on a keyboard. Or the small vibrations of a shirt, worn through the day. These ordinary motions, and others, could charge our devices and light our homes.