A team of Canadian researchers created a chin strap made from piezoelectric fiber composites (PFCs) that can generate electricity from jaw movements. When the strap is stretched by talking or chewing, an electrical charge is generated and could produce approximately 7 mW of power.
The researchers tested the how much power was generated when chewing gum for one minute while wearing the chin strap. The power output was ten µW, currently not sufficient for powering electrical devices. The team is working to increase the amount of power harvested by adding additional layers of PFCs to the strap to be able to adequately charge electronic devices.
Read more about the energy harvesting chin strap.