TY - GEN
T1 - A High-Density and Dual-Frequency PMUT Array Based on Thin Ceramic PZT for Endoscopic Photoacoustic Imaging
AU - Wang, Haoran
AU - Feng, Philip X.L.
AU - Xie, Huikai
N1 - Publisher Copyright:
© 2021 IEEE.
PY - 2021/1/25
Y1 - 2021/1/25
N2 - Photoacoustic imaging can be used for in vivo early cancer diagnosis due to its cross-sectional imaging capability and high contrast, but there always exists a tradeoff between resolution and imaging depth. For that piezoelectric micromachined ultrasonic transducer (pMUT) arrays with both higher-frequency and lower-frequency pMUT elements are needed for achieving high resolution and large imaging depth simultaneously. In this paper, we present the design, fabrication, and characterization of a high-density and dual-frequency pMUT array based on thin ceramic PZT, which consists of 128 pMUTs operating at 1.2 MHz and 128 pMUTs operating at 3.4 MHz. By using wafer bonding and chemical mechanical polishing techniques, ceramic PZT with high piezoelectric coefficients was thinned down to only 4 μm and employed as the piezoelectric layer of the designed pMUT array. The dual-frequency performance of the pMUT array was characterized with electrical impedance, vibration modes, cross-coupling, and acoustic sensing measurements. With a chip size of 7 ×7 mm and integration of 256 pMUTs with two operating frequencies into one array, the developed pMUT array shows a great potential for endoscopic photoacoustic imaging to achieve high-resolution and large imaging depth simultaneously.
AB - Photoacoustic imaging can be used for in vivo early cancer diagnosis due to its cross-sectional imaging capability and high contrast, but there always exists a tradeoff between resolution and imaging depth. For that piezoelectric micromachined ultrasonic transducer (pMUT) arrays with both higher-frequency and lower-frequency pMUT elements are needed for achieving high resolution and large imaging depth simultaneously. In this paper, we present the design, fabrication, and characterization of a high-density and dual-frequency pMUT array based on thin ceramic PZT, which consists of 128 pMUTs operating at 1.2 MHz and 128 pMUTs operating at 3.4 MHz. By using wafer bonding and chemical mechanical polishing techniques, ceramic PZT with high piezoelectric coefficients was thinned down to only 4 μm and employed as the piezoelectric layer of the designed pMUT array. The dual-frequency performance of the pMUT array was characterized with electrical impedance, vibration modes, cross-coupling, and acoustic sensing measurements. With a chip size of 7 ×7 mm and integration of 256 pMUTs with two operating frequencies into one array, the developed pMUT array shows a great potential for endoscopic photoacoustic imaging to achieve high-resolution and large imaging depth simultaneously.
KW - Piezoelectric micromachined ultrasonic transducer (pMUT)
KW - ceramic PZT
KW - dual-frequency
KW - endoscopic imaging
KW - pMUT array
KW - photoacoustic imaging
UR - http://www.scopus.com/inward/record.url?scp=85103451957&partnerID=8YFLogxK
U2 - 10.1109/MEMS51782.2021.9375356
DO - 10.1109/MEMS51782.2021.9375356
M3 - Conference contribution
AN - SCOPUS:85103451957
T3 - Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS)
SP - 891
EP - 894
BT - 34th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2021
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 34th IEEE International Conference on Micro Electro Mechanical Systems, MEMS 2021
Y2 - 25 January 2021 through 29 January 2021
ER -
