Hearing aids have made life far more convenient for people with impaired hearing. They are one of the most common forms of wearable Health Tech devices, and continue to improve at an amazing rate. Miniaturized digital processing has made it possible to create nearly-invisible models that hide in the patient’s ear canal, and that can be tuned to the specific frequency ranges where help is needed.
For all their advanced technology, hearing aids still have a very old fashioned problem; they need batteries. And as the devices get smaller, it becomes increasingly difficult for older users to replace the batteries when needed.
Researchers at École de Technologie Supérieure in Quebec, Canada, are developing system that would eliminate the need for swapping batteries. They have created a way to harvest energy from jaw movement to provide electricity to a rechargeable battery. The ear canal changes shape as a person’s jaw opens and closes. The researchers used a piezoelectric film in the hearing aid body to generate electricity. Piezoelectric materials move when an electrical current is applied, and generate an electrical current when they are moved. In this case, the motion of the jaw can move the film in the hearing aid and generate power to recharge the device’s battery.
As a result, talking and eating will help keep the hearing aid charged, without any need for external wires or other connections. The self-contained hearing aid can run longer without the need to change batteries.