A team of American and Canadian scientists unveiled on Thursday a device that uses human walking to generate a usable supply of electricity. The smart device must be strapped on the knee.

Scientists have been working for a long time on ways to transform the human body’s motion power into electricity. And now, the adapted knee brace seems to be the long-waited for device to help people to effortlessly harvest energy from body movement. The other similar devices scientists thought at before creating the knee brace were a shoe-mounted device and a backpack device. But they all proved inefficient because of different causes: despite it was light and nice, the shoe-mounted device did not generate enough electricity, while the backpack device was too heavy to wear, although it generated a lot of electricity as it bounced up and down while the person was walking. So, the knee brace proved to be the best energy-capturing device, taking into account that it is relatively light and can generate significant amounts of energy.

According to the team of scientists involved in this project, it seems that the brand new device can generate enough energy to power a cell phone for 30 minutes from the first minute of walking.

According to Doctor Douglas Weber of University of Pittsburgh, one of the authors of the new study, the first people that should start wearing the knee brace would be amputees, who need increasingly sophisticated prosthetics that require important quantities of energy.

"You need power to run your neural interface; you need it to run your powered joint, and so on. Getting that power is going to be really important,” said Douglas Weber.