Development and Characterization of Piezoelectric Artificial Cochlear with Micro Actuator Mimicking Human Cochlear

This paper presents the development of piezoelectric artificial cochlear (P-AC) capable of analyzing incoming acoustic or mechanical signals without external power source. The P-AC consists of membrane part and package part. The package part provides liquid environment through which the incoming signal is transmitted to membrane part. The membrane part responds to the transmitted signal and local area of the membrane part vibrates differently depending on its local resonant frequency. Previously in our group, we have demonstrated the feasibility of the P-AC with trapezoidal membrane part as sound analyzer by using mouth simulator as a sound input. In this research, we modified the P-AC to have the membrane part of logarithmically varying width. Also by incorporating mico-actuator into the package part that mimic the function of stapes bone in middle ear, we created similar environment to cochlear where human basilar membrane vibrates. The fabricated P-AC successfully demonstrates frequency separation of incoming mechanical signal from microactuator into several frequency bands within human hearing range.