Harvesting Energy from Regular, Day-to-Day Motions

Friday, October 30 2009

Duke University engineers have developed a novel approach that they believe can more efficiently harvest electricity from the motions of everyday life. Although motion is an abundant source of energy, only limited success has been achieved because the devices used only perform well over a narrow band of frequencies.

These so-called “linear” devices can work well if the character of the motion is fairly constant, such as the cadence of a person walking. However, the pace of someone walking, as with all environmental sources, changes over time and can vary widely.

“The ideal device would be one that could convert a range of vibrations instead of just a narrow band,” said Samuel Stanton, graduate student in Duke’s Pratt School of Engineering, working in the laboratory of Brian Mann, assistant professor of Mechanical Engineering and Materials Sciences. The team also included undergraduate Clark McGehee.

“Nature doesn’t work in a single frequency, so we wanted to come up with a device that would work over a broad range of frequencies,” Stanton said. “By using magnets to ‘tune’ the bandwidth of the experimental device, we were able verify in the lab that this new non-linear approach can outperform conventional linear devices.”