Mechanical and thermal simulations of a microactuator for the Stimulation of the Perilymph

The design of a microactuator serving as an implantable hearing aid to overcome ambylacousia was conducted by executing mechanical and thermal Finite Element Method (FEM) analyses using the ANSYS^® software simulation tool. To do so, the deflection conditions to be fulfilled by the system were determined. The two challenges were to achieve a sufficiently high resonance frequency and to accommodate the physiological restrictions in the middle ear and the cochlea defining the maximal size of the microactuator. A model of the mechanical system was created and modal analyses were carried out. In the next step, the force required to deflect the membrane in the static case and under damping of the cochlea was simulated. In a last step, a 3-D thermal model of the complete system including the micromagnetics was created to investigate the temperature rise in the system. This is important with respect to the implantation of the actuator into the human body, avoiding a necrosis of the human tissue.