Chewing Gum to Power Your Hearing Aids

Whether it's gum, tobacco or a piece of steak, every one of us chews something.
As outlandish as it may sound, researchers in Canada have used technology to turn mastication – and other movements of the jaw – into a source of electricity that could transform the way people power a range of electronic devices such as hearing aids.
"The human body has abundant sources of energy from the leg movements, or the arms swinging or general body motion," Aidin Delnavaz, Research Associate at Montreal's École de Technologie Supérieure, told CNBC.com in a phone interview. "In the region of the head… the most promising source of energy is the jaw movement."
Delnavaz and colleagues have designed a headset with a chinstrap made out of piezoelectric fiber composites (PFC) – material that can generate an electrical charge when it is stretched or put under stress – that is able to harvest energy as the jaw moves.
The headset's design consists of conventional elastic side straps, as well as 'smart' straps that fit under the chin and a head mounted device similar to headphones, helmets or earmuffs. When a user of the device chews, electricity is generated.
How much electricity could chewing generate? "We have an estimation of around seven milliwatts, which… in the scale of the small electronic devices is really huge," Delnavaz said. "For example, the power consumption of… hearing aid is about one milliwatt, so in this case we have enough energy in the jaw movement to power the hearing aid," he added.

While the potential of chewing is obvious, currently, the device can only create, "around ten microwatts," of harvestable energy, Delnavaz said.
To improve the capacity of the device, Delvanaz told CNBC.com that the PFC material used in the chinstrap – which is incredibly thin – could be 'thickened'. "We can actually 'stack up' several layers of PFC in the device and… add to the power output of the system," he said.
If it were fully developed, the device could help to lessen society's reliance on disposable batteries, helping people both save money and the environment. "Hearing aids rely on using batteries, either rechargeable batteries or disposable batteries," Delvanaz said.
"The problem for the consumer of these devices is… changing or recharging the battery for every two or three days. It's expensive and it also has some environmental effect, because dangerous chemicals exist in the batteries," he added.