Sneakers that store energy and charge smartphone batteries

Researchers from the University of Wisconsin-Madison, United States, have developed footwear capable of charging batteries ( tennis that stores energy ). The technology captures and stores the mechanical energy produced in the foot, converting it into electrical charge.

The power generated is enough to power a variety of mobile devices, such as smartphones, tablets, laptops, and flashlights. According to the responsible engineers, the project can serve as an energy source in remote or developing locations.

Tennis that stores energy

The duo responsible for the invention consists of Tom Krupenkin, professor of mechanical engineering, and J. Ashley Taylor, senior scientist in the department. In 2011, the two discovered the phenomenon known as " reverse electrohumidification , " one of the great enablers of power generation shoe manufacturing.

In preliminary experiments, testing the prototype can generate 10 watts per square meter. "A total of 20 watts gained on foot is no small feat, especially compared to most of the power requirements of modern mobile devices, " said Krupenkin, noting that a current cell phone requires less than 2 watts.

The device comprises two flat plates separated by a small space filled with a conductive liquid. The bottom plate is full of small holes through which bubbles form a gas under pressure. These bubbles grow until they touch the top plate, causing the explosion. The repeatability and speed of the bubble growth and collapse process pushes the electrical charge generated by the conductive fluid back and forth.

In the near future, shoes may be used by soldiers, for example, who need to carry a heavy battery for power radios, GPS, and night vision goggles. Technology can also mean a cheap source of energy for developing countries or communities in remote locations.