Abstract
In this paper, we report a fully microfabricated acoustic sensor for a novel artificial cochlear system. The developed sensor can detect the magnitude and the frequency of acoustic waves, and can convert the acoustic waves to the electric signals without any energy supply. The sensor is composed of a trapezoidal membrane made of P(VDF-TrFE) and a thin film electrode array on it. The membrane is designed to be vibrated by acoustic waves and to convert acoustic waves to electrical signals by virtue of the piezoelectric effect of the P(VDF-TrFE). In addition, the membrane detects the wave frequency according to the position of the resonating place which is realized by the varying membrane's width. To analyze the vibrating characteristics under the fluid-structure interaction, the sensor is mounted on a substrate including a fluid channel which is filled with a silicone oil of the lymph liquid model. The basic vibrating characteristics are evaluated by measuring the spatial distribution and the frequency dependence of the vibrating amplitude at various frequencies ranged from 0.50 to 10 kHz. The result shows that the sensor can realize the frequency selectivity at the frequencies ranged from 2.4 to 8.0 kHz.
