Energy Harvesting Journal
8 Jul 2014 | Canada
On a weekly basis, hundreds of millions of users worldwide must replace the button cell batteries in their hearing aids. Unfortunately, batteries are a source of environmental waste, a financial burden and somewhat time-consuming and requiring good dexterity to change. What if hearing-aids could be self-powered? Researchers at École de Technologie Supérieure are investigating energy harvesting to power hearing aids.
As alternatives to batteries, energy harvesting technologies are increasingly gaining interest. Energy harvesters, which are able to recover small amounts of energy from external sources such as solar power, thermal energy, or human body, are usually suitable for low power portable or wearable devices. Hearing aids are among wearable medical devices which have been substantially modified in recent years and are becoming less energy consuming.
Therefore, energy harvesting could be successfully applied to them. In addition to hearing aids, other types of in-ear devices such as electronic hearing protectors and communication earpieces could also benefit from energy harvesting technologies.
This research project to replace hearing aid batteries by energy harvesting technologies is important for Dr. Aidin Delnavaz, a postdoc researcher working on this project. It reminds him his grandmother who suffers from hearing loss and hardly goes anywhere without her hearing aids. "She always complained about her unit because of problems caused by batteries. Sometimes these hearing aids fail at parties, family evenings or during telephone conversation" explains Dr. Delnavaz.
Energy harvesting technologies for hearing aids The researchers have started by considering different sources of energy. Since the user wears the hearing aid, one possible power source would be the user and another would be the user's environment. Several innovative ideas have been recently proposed to use energy harvesting to power hearing aids. Light, body heat, electromagnetic waves, speaker vibrations, and radio frequency waves are sources of energy which have been already proposed for this application.