Nano-Electrodeposits of MEMS Directional Microphones for Hearing Aid Optimization
S.-S. Je, J. Kim, M.N. Kozicki, J. Chae
Arizona State University, US
Keywords: hearing aids, fitting, MEMS, microphone, nano-electrodeposits
Abstract:We present an in-situ non-electronic method for MEMS (Micro-Electro-Mechanical-Systems) microphone optimization by sensitivity adjustment via the growth/retraction of nano-electrodeposits to achieve high directionality in hearing aid applications. Using a DC bias at room temperature, nano-electrodeposits are electrochemically deposited/dissolved on a Ag-doped GeSe solid electrolyte film on a microphone diaphragm. The growth/retraction of the nano-electrodeposits generates mass/stress redistribution on the diaphragm, tuning the microphone sensitivity to incoming acoustic sources. Acoustic measurements demonstrate that the directional microphone can achieve a 1.3dB Directivity Index (DI) improvement.