Randomness and chaos in nature, as it turns out, can be a good thing—especially when trying to harvest energy from the movements of everyday activities. Duke University engineers believe they have come up with the theoretical underpinning that could lead to the development of energy-harvesting devices that are not only more versatile than those in use today, but also should be able to wring out more electricity from the motions of life.

Energy harvesting is the process of converting one form of energy, such as motion, into another form of energy, in this case electricity. Typically, energy harvesters make use of a piezoelectric material, which is usually a man-made laminate that produces small amounts of electricity when stressed or strained.

However, current energy-harvesting devices have been unable to efficiently make this energy conversion because the devices can only be “tuned” to a single frequency, or size of vibration. These so-called “linear” devices work well, for example, if the wind blows at a constant predetermined speed, or a person walks at a steady pace.

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