简介: |
Abstract
Hearing loss is a common disability in aging seniors and people who work long hours in noisy environments. For patients who are nearly deaf, surgeons often place an electrode array in cochlea, known as a cochlear implant, to stimulate auditory nerves by electric current. Recent medical research indicates that combination of a cochlear implant (electric-based) and a traditional hearing aid (acoustic-based) has proved to enhance speech recognition significantly. A grand challenge is to develop an intra-cochlear acoustic microactuator to realize the combined stimulations in cochlea.
In this presentation, I will discuss design, fabrication, and testing of a piezoelectric-based intra-cochlear microactuator. The microactuator employs a PZT thin film to transversely vibrate a diaphragm to generate pressure waves in cochlea. Major challenges affecting its vibration performance include electric circuit layout, electrode size, residual stresses, piezoelectric coefficients measurements, and fabrication processes. Testing in an aqueous environment shows that surrounding liquid presents significant added mass. Experimental measurements also indicate that the acoustic microactuator may experience a snap-through phenomenon. Finally, an acute animal test confirms that the intra-cochlear microactuator does produce pressure waves audible to the animal.
Biography
Dr. I. Y. (Steve) Shen is a Professor of Mechanical Engineering Department of the University of Washington. He is a Fellow of American Society of Mechanical Engineers (ASME), and is currently the Technical Editor of ASME Journal of Vibration and Acoustics. Professor Shen is a recipient of ASME N. O. Myklestad Award and IBM Partnership Award. Dr. Shen's general research area is vibration, dynamics, sensing, and actuation. In particular, his expertise includes PZT thin-film micro-sensors/actuators, insect dynamics, and spindle and rotor dynamics. In the areas of PZT thin films, he is developing micro-sensors and actuators for various future applications, such as intra-cochlear hearing aids, hybrid cochlear implants and structural health monitoring sensors. In the area of insect dynamics, he is studying vibration of flapping wings and pulsating thorax in order to develop sensors and actuators for motion control and guidance of flapping-wing micro-aerial vehicles. In the area of spindle and rotor dynamics, he is developing computational algorithms to predict vibration of complex rotating machines, such as hard disk drives and cyclic symmetric rotors. |
