Comparative analysis of mechanical characteristics of different topologies of the cantilever beam to mimic the function of the cochlea

According to the World Health Organization (WHO), approximately 5% of the world’s population has a hearing loss disability caused by various reasons. The cochlea is a spiral-shaped bone found in the inner ear that is capable of doing exceptional sound analysis, in terms of both frequency and intensity which allows the perception of sound frequency in the range of 20 Hz to 20 kHz. An artificial basilar membrane having various shapes has been developed but none of those covers the whole human audible frequency range. This paper compares the mechanical characteristics of the rectangular and taper piezoelectric cantilever to develop an artificial basilar membrane that mimics the human cochlea with high sensitivity. The cantilever beam is made up of molybdenum (Mo), aluminum nitride (AlN), tungsten (W) and the desired frequency range is obtained by varying the length and thickness of the cantilever beams. The 3D design and simulations were performed by COMSOL Multiphysics to study the Eigen frequency, displacement, and stress measurements of the cantilever. The Eigen frequency is observed to be increased with an increase in the thickness and decrease in the length for both rectangular and taper cantilever beam. The rectangular beam showed higher sensitivity and lower stresses compared to the taper beam. Therefore, the rectangular cantilever beam is more suitable to mimic the basilar membrane of the human cochlea.