TY - JOUR
T1 - Design and analysis of a PZT-based micromachined acoustic sensor with increased sensitivity
AU - Wang, Zheyao
AU - Wang, Chao
AU - Liu, Litian
N1 - Funding Information:
Manuscript received April 20, 2004; accepted February 28, 2005. This work was supported in part by the Fundamental Science Foundation of Tsinghua University under Grant JC2003061, and National Natural Science Foundation under Grant 60401009.
PY - 2005/10
Y1 - 2005/10
N2 - The ever-growing applications of lead zirconate titanate (PZT) thin films to sensing devices have given birth to a variety of microsensors. This paper presents the design and theoretical analysis of a PZT-based micro acoustic sensor that uses interdigital electrodes (IDE) and in-plane polarization (IPP) instead of commonly used parallel plate-electrodes (PPE) and through-thickness polarization (TTP). The sensitivity of IDE-based sensors is increased due to the small capacitance of the interdigital capacitor and the large and adjustable electrode spacing. In addition, the sensitivity takes advantage of a large piezoelectric coefficient d 33 rather than d 31, which is used in PPE-based sensors, resulting in a further improvement in the sensitivity. Laminated beam theory is used to analyze the laminated piezoelectric sensors, and the capacitance of the IDE is deduced by using conformal mapping and partial capacitance techniques. Analytical formulations for predicting the sensitivity of both PPE- and IDE-based microsensors are presented, and factors that influence sensitivity are discussed in detail. Results show that the IDE and IPP can improve the sensitivity significantly.
AB - The ever-growing applications of lead zirconate titanate (PZT) thin films to sensing devices have given birth to a variety of microsensors. This paper presents the design and theoretical analysis of a PZT-based micro acoustic sensor that uses interdigital electrodes (IDE) and in-plane polarization (IPP) instead of commonly used parallel plate-electrodes (PPE) and through-thickness polarization (TTP). The sensitivity of IDE-based sensors is increased due to the small capacitance of the interdigital capacitor and the large and adjustable electrode spacing. In addition, the sensitivity takes advantage of a large piezoelectric coefficient d 33 rather than d 31, which is used in PPE-based sensors, resulting in a further improvement in the sensitivity. Laminated beam theory is used to analyze the laminated piezoelectric sensors, and the capacitance of the IDE is deduced by using conformal mapping and partial capacitance techniques. Analytical formulations for predicting the sensitivity of both PPE- and IDE-based microsensors are presented, and factors that influence sensitivity are discussed in detail. Results show that the IDE and IPP can improve the sensitivity significantly.
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U2 - 10.1109/TUFFC.2005.1561640
DO - 10.1109/TUFFC.2005.1561640
M3 - Article
C2 - 16382637
AN - SCOPUS:28444485365
SN - 0885-3010
VL - 52
SP - 1840
EP - 1850
JO - IRE Transactions on Ultrasonic Engineering
JF - IRE Transactions on Ultrasonic Engineering
IS - 10
ER -