'Smart' chin strap can generate power as you eat

Imagine generating power to charge your smartphone as you munch your favourite chocolate, pizza or by talking to your girlfriend. With the 'smart' chin strap, the improbable is now possible.

Canadian researchers have created a 'smart' chin strap that can harvest energy from jaw movements.

In their study, researchers from the Ecole de technologie superieure (ETS) in Montreal, Canada, created an energy harvesting chin strap made from a single layer of piezoelectric fiber composites (PFCs).

They attached it to a pair of ear muffs using a pair of elastic side straps.

To ensure maximum performance, the chin strap was fitted snugly to the user, so when the user's jaw moved it caused the strap to stretch.

To test the performance of the device, the subject was asked to chew gum for 60 seconds while wearing the head-mounted device.

The maximum amount of power that could be harvested from the jaw movements was around 18 AuW.

"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 chin strap," explained study co-author Aidin Delnavaz.

For example, 20 PFC layers, with a total thickness of six mm, would be able to power 200 AuW.

The only expensive part of the energy harvesting device is the single PFC layer which costs around $20.

The device can generate electricity from eating, chewing and talking and power a number of small-scale implantable or wearable electronic devices, such as hearing aids, cochlear implants, electronic hearing protectors and communication devices, researchers emphasised.

Jaw movements have proved to be one of the most promising candidates for generating electricity from human body movements, with researchers estimating that an average of around 7 mW of power could be generated from chewing during meals alone.

The results of the device's performance were published in the journal Smart Materials and Structures.