Development of a micromachined piezoelectric microphone for aeroacoustics applications.
This paper describes the design, fabrication, and characterization of a bulk-micromachined piezoelectric microphone for aeroacoustic applications. Microphone design was accomplished through a combination of piezoelectric composite plate theory and lumped element modeling. The device consists of a 1.80-mm-diam, 3-microm-thick, silicon diaphragm with a 267-nm-thick ring of piezoelectric material placed near the boundary of the diaphragm to maximize sensitivity. The microphone was fabricated by combining a sol-gel lead zirconate-titanate deposition process on a silicon-on-insulator wafer with deep-reactive ion etching for the diaphragm release. Experimental characterization indicates a sensitivity of 1.66 microVPa, dynamic range greater than six orders of magnitude (35.7-169 dB, re 20 microPa), a capacitance of 10.8 nF, and a resonant frequency of 59.0 kHz.
Horowitz
Stephen
S
Department of Mechanical and Aerospace Engineering, Interdisciplinary Microsystems Group, University of Florida, Gainesville, Florida 32611-6250, USA.
Nishida
Toshikazu
T
Cattafesta
Louis
L
Sheplak
Mark
M
D000162:Acoustics / Q000295:instrumentation*; D000401:Aircraft; D001274:Atmospheric Pressure; D025802:Electric Capacitance; D017097:Electric Impedance; D004867:Equipment Design; D020342:Finite Element Analysis; D007854:Lead / Q000737:chemistry*; D008904:Miniaturization; D008956:Models, Chemical; D009622:Noise; D015203:Reproducibility of Results; D012825:Silicon / Q000737:chemistry*; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D014732:Vibration; D015040:Zirconium / Q000737:chemistry*
C065536:lead titanate zirconate; D007854:Lead; D015040:Zirconium; D014025:Titanium; D012825:Silicon