It may not be a very aesthetic accessory, but it can be useful: a strap that fits over the chin and converts jaw movements into electricity.
Thus, chewing could produce the energy needed to charge small devices, such as hearing aids.
That is the invention of a team of engineers, who created the strap with a "smart" material that charges with electricity when stretched.
The researchers, who specialize in hearing technology, want to make use of that energy so as not to rely on disposable batteries.
How does it work:
Researchers at the École de Technologie Supérieure in Montreal, Canada, used a piezoelectric material for the strap and attached it to earmuffs to make their prototype.
Thus, chewing gum for 60 seconds, they obtained 18 microwatts of electricity.
This may not be much: to power something as small as a hearing aid would take 20 of these straps.
But engineers say this could be fixed by adding more layers of the material to the belt.
20 layers could power a 200 microwatt smart headphones. The strap would remain comfortable, according to its creators.
The results of the experiment are published in the specialized journal Smart Materials and Structures, of the international organization Institute of Physics.