The nightmare of your mobile phone running out of power mid-conversation could be over, for researchers at the University of Wisconsin have invented a device that, placed in a shoe，can harvest the kinetic energy from walking to power a mobile phone。
Scientists have been working for years on trying to harness the energy produced from walking, which theoretically is sufficient to power a light bulb, smart phone or even a laptop。
But until now their solutions have been too cumbersome, or have not produced enough power to be useful。
藏在鞋子中的行走充电装置
Now, engineering experts Tom Krupenkin and Ashley Taylor say they have come up with a technology which can produce as much as a hefty 10 watts of power。
After testing various liquids, the researchers chose a metal alloy called Galinstan. Used in thermometers, it is similar to mercury but not poisonous。
Two small pouches, placed in the bottom of a shoe, are filled with the fluid and generate a current whenever they are compressed by the foot’s up and down motion。
Transferring the energy from a device in a foot to a phone in the hand presents an obvious hurdle。
Rather than plugging a cable into a shoe, the Wisconsin researchers suggest installing a wireless transmitter in the heel. This could make radio contact with mobile phone base stations。
Professor Krupenkin said: "Humans were‘very powerful energy-producing machines’ that could produce as much as a kilowatt of power while sprinting."