d33 mode piezoelectric diaphragm based acoustic transducer with high sensitivity

Abstract This paper presents the design, fabrication, and characterization of an acoustic transducer using a piezoelectric freestanding bulk diaphragm as the sensing element. The diaphragm bearing the spiral electrode operates in d 33 mode, which allows the in-plane deformation of the diaphragm to be converted to the out-of-plane deformation and generates an acoustic wave in the same direction. A finite element code is developed to reorient the material polarization distribution according to the poling field calculated. The first four resonance modes have been simulated and verified by impedance and velocity spectra. The sensitivity and the sound pressure level of the transducer were characterized. The realized sensitivity of 126.21 μV/Pa at 1 kHz is nearly twenty times of the sensitivity of a sandwich d 31 mode transducer.

[1]  R. Paradies,et al.  Finite element modeling of piezoelectric elements with complex electrode configuration , 2009 .

[2]  Eunki Hong.  Surface micromachined peristaltic pumps using lead zirconate titanate film , 2003 .

[3]  Jianmin Miao,et al.  Displacement and resonance behaviors of a piezoelectric diaphragm driven by a double-sided spiral electrode , 2012 .

[4]  Paul Muralt,et al.  Piezoelectric actuation of PZT thin-film diaphragms at static and resonant conditions , 1996 .

[5]  Sang-Gook Kim,et al.  MEMS power generator with transverse mode thin film PZT , 2005 .

[6]  R. Paradies,et al.  Numerical Stress Investigation for Piezoelectric Elements with a Circular Cross Section and Interdigitated Electrodes , 2007 .

[7]  Robert T. Effinger,et al.  Radial Field Piezoelectric Diaphragms , 2004 .

[8]  R. Smith,et al.  Vibration of micromachined circular piezoelectric diaphragms , 2006, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[9]  A. Safari,et al.  Piezoelectric and Acoustic Materials for Transducer Applications , 2008 .

[10]  S. Trolier-McKinstry,et al.  Micromachined piezoelectric diaphragms actuated by ring shaped interdigitated transducer electrodes , 2005 .

[11]  M. Okuyama,et al.  Diaphragm deflection control of piezoelectric ultrasonic microsensors for sensitivity improvement , 2007 .

[12]  Jianmin Miao,et al.  Acoustic transducers with a perforated damping backplate based on PZT/silicon wafer bonding technique , 2009 .

[13]  Jianmin Miao,et al.  Fabrication of piezoelectric MEMS devices-from thin film to bulk PZT wafer , 2010 .