DocumentCode :
813038
Title :
A Compact, Low-Power, and Electromagnetically Actuated Microspeaker for Hearing Aids
Author :
Je, Sang-Soo ; Chae, Junseok
Author_Institution :
Dept. of Electr. Eng., Arizona State Univ., Tempe, AZ
Volume :
29
Issue :
8
fYear :
2008
Firstpage :
856
Lastpage :
858
Abstract :
In this letter, we present an electromagnetically actuated microspeaker with microelectromechanical systems (MEMS) technology to reduce form factor, cost, and power consumption in hearing aid applications. The microspeaker has multilayer copper coils, a NiFe soft magnet on a polyimide membrane, and a NdFeB permanent magnet on the perimeter. The coil impedance is measured at 1.5 Omega and shows a very flat response across the audio frequency range. The device operates at a very low power, the lowest in MEMS speakers, comparable to that of the macro- size counterparts. A single-turn microspeaker with a diameter of 2.5 mm consumes 11.6 and 0.13 mW to generate a sound pressure level of 129 and 106 dB at 1 kHz, respectively. The measurement uncertainty is less than 10%, and the reproducibility is within 36% among the tested devices.
Keywords :
biomedical electronics; hearing aids; iron compounds; loudspeakers; low-power electronics; measurement uncertainty; microactuators; neodymium compounds; nickel compounds; permanent magnets; MEMS technology; NdFeB; NiFe; electromagnetically actuated microspeaker; frequency 1 kHz; hearing aids; measurement uncertainty; microelectromechanical system; multilayer copper coil; permanent magnet; polyimide membrane; power 0.13 mW; power 11.6 mW; size 2.5 mm; soft magnet; Auditory system; Coils; Copper; Costs; Energy consumption; Hearing aids; Magnetic multilayers; Microelectromechanical systems; Micromechanical devices; Soft magnetic materials; Acoustic device; acoustic device fabrication; actuator; hearing aids; loudspeaker; microactuators; microelectromechanical systems (MEMS); micromachining; microspeaker;
fLanguage :
English
Journal_Title :
Electron Device Letters, IEEE
Publisher :
ieee
ISSN :
0741-3106
Type :
jour
DOI :
10.1109/LED.2008.2000948
Filename :
4571131
Link To Document :
بازگشت