The day may soon come when your cellphone - or just about any other portable electronic device - could be powered by simply taking a walk, two US scientists say.
Tom Krupenkin and J. Ashley Taylor, both engineering researchers at the University of Wisconsin-Madison, have described a new energy-harvesting technology that promises to dramatically reduce our dependence on batteries and instead capture the energy of human motion to power portable electronics.
"Humans, generally speaking, are very powerful energy-producing machines," said Krupenkin, a UW-Madison professor of mechanical engineering. "While sprinting, a person can produce as much as a kilowatt of power."
Capturing even a small fraction of that energy, Krupenkin points out, is enough to power a host of mobile electronic devices - everything from laptop computers to cell phones to flashlights.
In their study, Krupenkin and Taylor describe a novel energy-harvesting technology known as "reverse electrowetting," where mechanical energy is converted to electrical energy by using a micro-fluidic device consisting of thousands of liquid micro-droplets interacting with a novel nano-structured substrate.
This technology could enable a novel footwear-embedded energy harvester that captures energy produced by humans during walking, which is normally lost as heat, and converts it into up to 20 watts of electrical power that can be used to power mobile electronic devices, they said.
Even though energy harvesting is unlikely to completely replace batteries in the majority of mobile applications, the UW-Madison researchers believe it can play a key role in reducing cost, pollution and other problems associated with battery use.
"Humans, generally speaking, are very powerful energy-producing machines," said Krupenkin, a UW-Madison professor of mechanical engineering. "While sprinting, a person can produce as much as a kilowatt of power."
Capturing even a small fraction of that energy, Krupenkin points out, is enough to power a host of mobile electronic devices - everything from laptop computers to cell phones to flashlights.
In their study, Krupenkin and Taylor describe a novel energy-harvesting technology known as "reverse electrowetting," where mechanical energy is converted to electrical energy by using a micro-fluidic device consisting of thousands of liquid micro-droplets interacting with a novel nano-structured substrate.
This technology could enable a novel footwear-embedded energy harvester that captures energy produced by humans during walking, which is normally lost as heat, and converts it into up to 20 watts of electrical power that can be used to power mobile electronic devices, they said.
Even though energy harvesting is unlikely to completely replace batteries in the majority of mobile applications, the UW-Madison researchers believe it can play a key role in reducing cost, pollution and other problems associated with battery use.
