Energy Harvesting for In-Ear Devices Using Ear Canal Dynamic Motion

In this paper, we study the possibility of using energy harvesting from ear canal dynamic motion as a source of power to replace the use of batteries for in-ear devices. Two hand-made micropower generators capable of scavenging energy from ear canal deformation are presented in this paper: 1) a hydroelectromagnetic energy harvester and 2) a flexible piezoelectric generator. The experimental results show that 3.3 mJ of energy per mouth opening and closing cycle is available from ear canal dynamic motion. If we consider that possibly thousands of such cycles occur daily, ear canal dynamic motion could prove to be a likely source of energy for in-ear applications.