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[Image above] Credit: Michigan Engineering; YouTube 

Piezoelectricity literally means electricity from pressure, and that’s just what it is—piezoelectric materials accumulate electric charge in response to mechanical stress. Many ceramics exhibit the piezoelectric effect, as do some naturally occurring crystals (like quartz) and several biological materials, such as dry bone, tooth component dentin, and even DNA. 

Because these materials have such interesting properties, piezoelectrics have been proposed as components in a wide range of energy-mindful devices, gadgets, and gizmos—including piezo-powered light-up running belts, cookware, shoes, backpacks, dance floors, roads, and more.

University of Michigan researchers are now putting piezoelectric materials to flight as part of a new design for morphing aircraft wings. The wings, which will likely find their way into unmanned aircraft sooner and manned aircraft later, would help lighten aircraft, saving energy and fuel, and allow more agile fliers. Watch this short three-minute video to learn more.

Credit: Michigan Engineering; YouTube 

And speaking of the promise of piezoelectrics, researchers from Sonomax-ÉTS Industrial Research Chair in In-ear Technologies (CRITIAS) at École de technologie supérieure (ÉTS) in Montreal, Canada have fashioned a piezoelectric fiber composite chinstrap that collects energy as you chew.

The awkward looking device—a single layer of PFC attached to earmuffs—generated up to 18 μW of power, although it issued a more standard output of about 10 μW, from just 60 seconds of chewing.

“The power level we achieved is hardly sufficient for powering electrical devices at the moment; however, we can multiply the power output by adding more PFC layers to the chinstrap. For example, 20 PFC layers, with a total thickness of 6 mm, would be able to power a 200 µW intelligent hearing protector,” says co-author Aidin Delnavaz in an Institute of Physics press release.

The paper, published in Smart Materials and Structures, is “Flexible piezoelectric energy harvesting from jaw movements” (DOI: 10.1088/0964-1726/23/10/105020).

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A piezoelectric chinstrap harvests energy from jaw movement. Credit: IOP