Title:

Micromachined Optical Microphones for Acoustic Instrumentation and Hearing Aid Applications

Speaker:

Dr. Levent Degertekin

Affiliation:

The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology

When:

Thursday, February 24, 2011 at 11:00:00 AM   Add to Calendar

Where:

Love Building, Room 109

Host:

Timothy Hsu
tissue@gatech.edu

Abstract

Micromachined silicon microphones based on capacitive detection are now widely used in cell phones and other high volume acoustics applications. Despite this success, these microphones are limited in their noise and bandwidth for applications requiring small size and high performance. With our collaborators, we have been working on optical detection schemes for realizing low noise micromachined microphones based on the high sensitivity of interferometric displacement detection. In this talk, we will first discuss the diffraction based optical detection method with its advantages and limitations. We will describe mm size omni-directional microphones which can achieve 20dBA noise with 20kHz or more bandwidth. These microphones are currently being commercialized. We will then move on to a biomimetic directional microphone based on the ears of a parasitoid Ormia Ochracea, and motivate its applications in hearing aids and acoustic intensity probes. These microphones provide highly sensitive pressure gradient measurements with a very small size. Finally, we will discuss how we use integrated electrostatic actuators of the microphones in a feedback loop to electronically control both the frequency response and the directivity of these biomimetic microphones.

Biography

See Dr. Levent Degertekin's webpage

Notes

Refreshments will be served.