Ear Canal Insertion-Type Piezoelectric Bone Conduction Actuator of Bridge Structure

Abstract

Hearing loss in people is increasing because of a rise in the usage of wireless audio multimedia devices. Hearing aids are used as representative hearing rehabilitation devices. Bone conduction hearing aids are recommended for problems in the eardrum and middle ear. Bone conduction is classified according to the driving method into two types, electromagnetic and piezoelectric. Electromagnetic bone conduction causes skin disease and aesthetic problems due to transplantation, high power consumption, and external interference. Piezoelectric bone conduction converts electrical energy into mechanical vibrations, and the characteristics change linearly with size. However, the driving force of ear canal insertion of the piezoelectric body is limited because of the ear canal anatomy. In this paper, a piezoelectric actuator with a bridge structure inserted into the ear canal is proposed. The proposed method is that the displacement amplification ratio was derived using the formula of a bridge-type structure, and the displacement and resonance frequency were derived by finite element analysis (FEA) using different variables. The piezoelectric actuator was fabricated on the basis of FEA simulation results and verified through an artificial mastoid for stimulation in the ear canal. It is expected that the proposed piezoelectric actuator can be used in the various fields for sound and precision control.

Finite Element Modeling and Test of Piezo Disk with Local Ring Electrodes for Micro Displacement

“…Such actuators can convert electrical energy into mechanical energy under an electric field and produce precision mechanical displacement [1][2][3]. High precision micro-drive and micro-positioning technology are needed in the technical fields of optical engineering [4], microelectronic manufacturing [5], aerospace [6], ultra-precision manufacturing [7], micro-robotics [8,9], medicine and genetic engineering [10,11]. Precision actuators with a piezoelectric component as the core show micro/nano displacement resolution.…”