Remember your mom telling you to make sure you chewed your food throughly? It's seems that mother did know best since it turns out that chewing can do much more then power your metabolism. Drs Aidin Delnavaz and Jeremie Voix, mechanical engineers at the Ecole de Technologie Superieure in Canada have discovered that the energy harnessed from chewing can be used to vastly increase available energy needed for cochlear implants and could power some small devices to boot! Chewing can produce about 580 joules of energy in a day and utilizing that energy brings some exciting possibilities.

Through their work on auditory technology (powered ear-muffs and cochlear implants) they discovered that the chin strap used to attach experimental earmuffs were actually harvesting energy as their subjects quickly moved their jaws as in chewing motions! "we realized that when you're moving your jaw, the chin is really moving the furthest, and if you are wearing some safety gear the chin strap could harvest a lot of energy."
They decided to try and harvest energy from the chewing chin, using what is called the "piezoelectric effect": when certain materials are pressed or stretched ("piezo" comes from the Greek word for squeeze), they acquire an electrical charge.
By making a strap from commercially available piezoelectric material, then attaching it to earmuffs and fitting it snugly around Dr Delnavaz's chin, they built a prototype. When he chewed gum for 60 seconds, they measured up to 18 microwatts of generated power!
This might not sound like much but "We multiplied the power output by adding more "piezoelectric fibre composite layers to the chin strap," The strap is comfortable. Dr Delnavaz wore the prototype version "for many hours" for testing and never felt chewing or talking were restricted. The vision is mostly for situations where people are already wearing a chin strap, and could plug in a small but essential gadget.
It can greatly benefit military soldiers wearing head protection and communicating using earpieces. Voix says"I cycle to work every day, I wear my helmet... Why not have my bluetooth dongle recharged by that strap?" Pass the Double Bubble!