For the first time, scientists have demonstrated a "natural" battery for implantable electronic devices that is powered by the ear itself. The demonstration was tested on guinea pigs, and showed that implants can utilize the inner ear's electrical potential without disrupting hearing. The device has the potential to help millions of people.
This "natural battery" works via the cochlea, where the ear's battery pumps ions via cells in a membrane. Because there is an irregular level of potassium and sodium on opposing sides of the membrane, an electrical voltage is created. In order for a device to use that energy without interfering with hearing, it could only use a small amount of the "battery."
Konstantina Stankovic, a Massachusetts Eye and Ear Infirmary otologic surgeon, offered this statement. "In the past, people have thought that the space where the high potential is located is inaccessible for implantable devices, because potentially it's very dangerous if you encroach on it. We have known for 60 years that this battery exists and that it’s really important for normal hearing, but nobody has attempted to use this battery to power useful electronics."
Researchers implanted the device in the ears of guinea pigs, then monitored their wireless signals with external devices. The animals showed no signs of hearing trouble. Moving forward, this method could allow for the implantation of electronic devices in the ear, which would then send information about therapy responses and its chemical state.