Designing a piezoelectric stack for incus driving actuator using finite element method

Design of a piezoelectric stack for incus driving actuator characterized by small size, low power consumption and broad frequency bandwidth for a middle ear implant was presented in this paper. To aid the design process, a coupling biomechanics model of the human middle ear and the piezoelectric stack actuator was constructed. This model was build based on a complete set of computerized tomography section images of a healthy volunteer´s left ear by reverse engineering technology. The result shows that the stapes footplate displacement stimulated by the designed piezo-stack actuator´s excitation at 10.5 V rms was equivalent to that from acoustic stimulation at 90 dB SPL, which is adequate stimulation to the ossicular chain. The corresponding power consumption is 0.03 mW per volt of excitation at 1 kHz, which is low enough for the actuator to be used in a middle ear implant.