Thin ceramic PZT dual-and multi-frequency pMUT arrays for photoacoustic imaging  

作　　者：Qincheng Zheng Haoran Wang Hao Yang Huabei Jiang Zhenfang Chen Yao Lu Philip X.-L.Feng Huikai Xie 

机构地区：[1]School of Integrated Circuits and Electronics,Beijing Institute of Technology(BIT),100081 Beijing,China [2]Department of Electrical and Computer Engineering,University of Florida,Gainesville,FL 32611,USA [3]Department of Medical Engineering,University of South Florida,Tampa,FL 33620,USA [4]MEMS Engineering and Materials Inc.,Sunnyvale,CA 94086,USA [5]BIT Chongqing Institute of Microelectronics and Microsystems,400030 Chongqing,China

出　　处：《Microsystems & Nanoengineering》2022年第6期23-34,共12页微系统与纳米工程（英文）

基　　金：the National Institutes of Health(NIH)under award#R01EB020601;the National Key R&D Program of China under award#2018YFF01010904.

摘　　要：Miniaturized ultrasonic transducer arrays with multiple frequencies are key components in endoscopic photoacoustic imaging(PAI)systems to achieve high spatial resolution and large imaging depth for biomedical applications.In this article,we report on the development of ceramic thin-film PZT-based dual-and multi-frequency piezoelectric micromachined ultrasonic transducer(pMUT)arrays and the demonstration of their PAI applications.With chips sized 3.5mm in length or 10mm in diameter,square and ring-shaped pMUT arrays incorporating as many as 2520 pMUT elements and multiple frequencies ranging from 1 MHz to 8 MHz were developed for endoscopic PAI applications.Thin ceramic PZT with a thickness of 9μm was obtained by wafer bonding and chemical mechanical polishing(CMP)techniques and employed as the piezoelectric layer of the pMUT arrays,whose piezoelectric constant d_(31)was measured to be as high as 140 pm/V.Benefiting from this high piezoelectric constant,the fabricated pMUT arrays exhibited high electromechanical coupling coefficients and large vibration displacements.In addition to electrical,mechanical,and acoustic characterization,PAI experiments with pencil leads embedded into an agar phantom were conducted with the fabricated dual-and multi-frequency pMUT arrays.Photoacoustic signals were successfully detected by pMUT elements with different frequencies and used to reconstruct single and fused photoacoustic images,which clearly demonstrated the advantages of using dual-and multi-frequency pMUT arrays to provide comprehensive photoacoustic images with high spatial resolution and large signal-to-noise ratio simultaneously.

关 键 词：CERAMIC PIEZOELECTRIC DUAL 

分 类 号：TQ174[化学工程—陶瓷工业]