Abstract:Objective To design an improvement plan of piezoelectric actuator with displacement magnification structure, so as to reduce power consumption of the existing incus-stimulating piezoelectric actuator for middle ear implant. Methods First, based on anatomical structure of human ear, the piezoelectric actuator with displacement magnification structure and the one just composed of piezoelectric stack were designed, respectively, and the corresponding coupled mechanical models of the middle ear and the piezoelectric actuator were established. By comparing the calculation results from the two types of coupling mechanical models, the hearing compensation property and power consumption of the actuator before and after the implantation of displacement magnification structure were analyzed. Results After adding the displacement magnification structure, the sound pressure level (SPL) at 1 kHz frequency was increased from 100 dB to 113 dB, when the piezoelectric actuator was stimulated by 10.5 V effective voltage. In addition, when the actuator was stimulated by the piezoelectric stack, its power consumption at the frequency of 1, 2 and 4 kHz were 6.42, 1.56 and 0.28 mW, respectviely; after introducing the displacement magnification structure, power consumption at the above-mentioned 3 frequencies decreased to 0.39, 0.09 and 0.01 mW, resepectively. Conclusions Piezoelectric actuator with displacement magnification structure in this study can improve hearing compensation ability of the incus-stimulating middle ear implant and effectively reducing the power consumption. The research findings will help to further improve the structure design of middle ear implant, thus achieving better hearing compensation effect.