TY - GEN
T1 - Optical sensing in a directional MEMS microphone inspired by the ears of the parasitoid fly, Ormia Ochracea
AU - Cui, Weili
AU - Bicen, Baris
AU - Hall, Neal
AU - Jones, Stephen A.
AU - Degertekin, F. Levent
AU - Miles, Ronald N.
PY - 2006
Y1 - 2006
N2 - The fabrication and characterization of a biomimetic MEMS directional microphone with integrated optical readout is presented. The use of diffraction-based optical interferometric detection with this novel microphone diaphragm avoids key limitations imposed by capacitive sensing, which is commonly used in miniature microphones. In this study, a biologically-inspired microphone with inter-digitated fingers is fabricated on a silicon substrate using a combination of surface and bulk micromachining techniques. The 1mm×2mm microphone diaphragm is made of polysilicon and has stiffeners and carefully designed hinge supports to ensure that it responds like a rigid body on flexible hinges. The diaphragm is designed to respond to pressure gradients, giving it a first-order directional response to incident sound. This mechanical structure is integrated with a compact optoelectronic readout system. The directivity measurements show the expected figure-8 directivity pattern with a 21dB difference between the maximum and minimum at the first diaphragm resonance frequency of 2 kHz. This concept has the potential of allowing the fabrication of low noise, directional miniature microphones with high sensitivity for hearing aid applications.
AB - The fabrication and characterization of a biomimetic MEMS directional microphone with integrated optical readout is presented. The use of diffraction-based optical interferometric detection with this novel microphone diaphragm avoids key limitations imposed by capacitive sensing, which is commonly used in miniature microphones. In this study, a biologically-inspired microphone with inter-digitated fingers is fabricated on a silicon substrate using a combination of surface and bulk micromachining techniques. The 1mm×2mm microphone diaphragm is made of polysilicon and has stiffeners and carefully designed hinge supports to ensure that it responds like a rigid body on flexible hinges. The diaphragm is designed to respond to pressure gradients, giving it a first-order directional response to incident sound. This mechanical structure is integrated with a compact optoelectronic readout system. The directivity measurements show the expected figure-8 directivity pattern with a 21dB difference between the maximum and minimum at the first diaphragm resonance frequency of 2 kHz. This concept has the potential of allowing the fabrication of low noise, directional miniature microphones with high sensitivity for hearing aid applications.
UR - https://www.scopus.com/pages/publications/33750099837
M3 - Conference contribution
SN - 0780394755
SN - 9780780394759
T3 - Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)
SP - 614
EP - 617
BT - 19th IEEE International Conference on Micro Electro Mechanical Systems
T2 - 19th IEEE International Conference on Micro Electro Mechanical Systems
Y2 - 22 January 2006 through 26 January 2006
ER -