Design of Highly Sensitive and Area Efficient Titanium Based MEMS Capacitive Pressure Sensor for Cochlear Implants

Cochlear implants have been widely used as a hearing aid for all age groups. In this paper, the design, simulation, and analysis of a highly sensitive, area efficient MEMS capacitive pressure sensor for cochlea implants is presented. The proposed sensor consists of a fixed electrode and a suspended diaphragm which deflects in response to applied pressure, altering the capacitance between the electrodes. The sensor's membrane was analysed and simulated using COMSOL software for rectangular and circular geometries using Titanium, Silicon and Silicon nitride as materials and their electrostatic behavior under various operating conditions were observed. The results demonstrates that with 100kPa input pressure, the circular membrane made of titanium performed better with sensitivity of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$5.27\times 10^{-19}\text{pF}/\text{Pa}$</tex> and a wide dynamic range of 70MPa. The findings from this proposed study provides a critical observation and enhancement for the optimization of MEMS capacitive sensors and their integration in cochlea implants application.