Imagine never having to charge an iPod.
Duke researchers have brought this vision closer to reality through developing a device capable of harvesting energy from motion. The study, funded by the U.S. Office of Naval Research, used nonlinear interactions between magnets to gain energy from day-to-day activities such as walking.
“Most of the previous work done in this area has developed devices capable of pulling a relatively large amount of energy out of a small range of frequencies,” said Brian Mann, lead researcher in the study and assistant professor of mechanical engineering. “This device, however, can pull energy out of a much broader range.”
The device is able to do so because of the researchers’ unique approach, said Samuel Stanton, researcher in the study and a graduate student in engineering.
“Past studies have focused on using linear systems, which only allowed devices to be efficient within a narrow frequency,” he said.
This research team, however, was able to use nonlinear systems to their advantage.
“What we’re doing is embracing nonlinearity instead of trying to design around it or applying controls to mitigate it,” Stanton said.
As a result, the device is able to provide a renewable source of energy from activities that entail changing frequencies, such as the movement of a car. This holds many implications for the future of energy, potentially replacing the battery as a power source.
Possible future applications of the device range from powering iPods and cell phones to medical sensors and devices such as pacemakers, using the energy created from walking.
One of the major benefits of the device is its practicality. Mann said the device can be implanted into hard-to-reach places such as the inside of a bridge to power a structural health sensor, generating power from natural vibrations. He added that one will never have to go back to the sensor to replace a battery.
Mann said this may have a significant effect on the automotive industry. Instead of implementing extensive wiring throughout a car’s body to power functions such as electric window movement, the device could simply be implanted within a car door.
At this point in development, the device carries a low capacity for generating energy. Stanton said, however, that the principle behind the device is more significant than the device itself.
“The scale of the device would be more appropriate for small electronics, but the idea is more far-reaching,” he said.
Researchers also foresee a positive impact on the environment.
“It would reduce the environmental footprint by having devices that generate their own power, eliminating the need for lead acid batteries,” Stanton said.
Get The Chronicle straight to your inbox
Signup for our weekly newsletter. Cancel at any time.