Researchers Create Body-Powered Electronic Implant

Posted by Bob Michaels on November 9, 2012
A close-up of a chip, equipped with a radio transmitter, that is powered by a natural battery found in the mammalian ear. (Image by Patrick P. Mercier)
Managing a power source for a medical implant has been a daunting challenge for many healthcare researchers and scientists. However, new technology from the Massachusetts Eye and Ear Infirmary (Boston) and the Division of Health Sciences and Technology at Harvard-MIT (Cambridge) may change that.

Scientists at the shared research center created a specialized microchip that is powered by the body’s natural chemistry. While the microchip is only able to generate a very small current, the device generated enough current to power a small radio transmitter.

The microchip works by exploiting concentration gradients of potassium and sodium ions in the ear. When an ear is functioning properly, it converts mechanical sound vibrations into an electrochemical signal. This signal can then be sent directly to the brain. One important part of the ear is the cochlea. In the cochlea is a membrane that pumps sodium and potassium ions to create a gradient.

This imbalance of ions creates an electrical voltage that can be exploited by small electronic implants. According to researchers, this voltage is the highest that can be found anywhere in the body. However, this voltage is still extremely low.

To avoid hearing loss, researchers could only exploit a small amount of this electrical current. By creating a small radio transmitter that sent signals every few minutes, researchers were able to power the device without causing negative changes in hearing. To date, the technology has been successfully tested in guinea pigs.

For more information on this technology, visit the MIT News.