Development of a Polyimid Membrane for Electromagnetic Middle- Ear Actuators

For a middle ear microactuator for the stimulation of the round window, based on the principle of the "balanced armature", the manufacturing routes and characterization of two main components are presented and discussed. The parts of a polyimide membrane pre-stressed on a frame and a spacer for magnetic components were processed using micro technology and 3D printing. The resonance frequency, the spring constant, the extensional stiffness and the elastic modulus of the membrane was analysed via laser Doppler vibrometry and nanoindentation. Simulations determined that the membrane ought to have a spring constant of 1.6 kN/m, which were not yet achieved in the final membranes with 1.05 kN/m and 1.33 kN/m. Therefore, further development is necessary to meet the exact requirements for the actuator.