cMUT阵元的声学分析与环形扫描成像  

Sound analysis of cMUT element and circular scanning imaging

作　　者：高鹏飞[1] 何常德[1] 张彦军[1] 张文栋[1] 王红亮[1] 任勇峰[1] 党荣 李一凡 王子渊 孟亚楠 沈姝君 GAO Pengfei;HE Changde;ZHANG Yanjun;ZHANG Wendong;WANG Hongliang;REN Yongfeng;DANG Rong;LI Yifan;WANG Ziyuan;MENG Yanan;SHEN Shujun(State Key Laboratory of Dynamic Testing Technology,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学省部共建动态测试技术国家重点实验室,太原030051

出　　处：《应用声学》2022年第2期293-300,共8页Journal of Applied Acoustics

基　　金：国家重点研发计划项目(2018YFF0110500);中北大学电子测试技术国家重点实验室项目(6142001200408);国家重大科学仪器研制项目(61927807);山西省“1331工程”重点学科建设计划项目。

摘　　要：电容式微机械超声换能器(cMUT)具有宽带宽、灵敏度高、机械阻抗低和与电子电路集成制造等优点。由于超声换能器声场设计的好坏决定了成像质量的优劣,为了明确阵元参数与辐射声场的关系,该文对不同的阵元参数进行了计算仿真。与压电陶瓷超声换能器的结构不同,cMUT阵元是由多个电容单元(cell)并联构成。因此分析了cell的半径、cell数量、间距、振动频率等阵元参数与辐射声场分布、远近场分界点、辐射声压、指向性的关系,并进行了声轴声压与指向性实验测试验证。理论与实验测试结果基本一致。通过仿真计算,选用一种已制备的指向性强、发射性能好的cMUT单阵元器件对鸡骨进行了环形扫描和成像,实现了对生物体组织横截面的超声CT成像,验证了所制备的cMUT器件的可用性。此研究对工业与医学成像领域具有重要的参考价值。Capacitive micromechanical ultrasonic transducer(cMUT)has the advantages of wide bandwidth,high sensitivity,low mechanical impedance and integrated manufacturing with electronic circuits.Because the sound field design of ultrasonic transducer determines the imaging quality,in order to clarify the relationship between array parameters and radiated sound field,different array parameters are calculated and simulated in this paper.Different from the structure of the piezoelectric ultrasonic transducer,cMUT element is made up of multiple(cell)shunt capacitor unit.Therefore,the relationship between cell parameters such as cell radius,cell number,spacing and vibration frequency and radiated sound field distribution,far-near field boundary point,radiated sound pressure and directivity is analyzed,and the experimental test of sound axis sound pressure and directivity is carried out.The theoretical results are basically consistent with the experimental results.Through simulation calculation,a prepared cMUT single array component with strong directivity and good emission performance was selected to scan and image the chicken bone,which realized the ultrasonic CT imaging of the cross section of biological tissue,and verified the availability of the prepared cMUT device.This research has important reference value for the field of industrial and medical imaging.

关 键 词：电容式微机械超声换能器 声场 指向性 轴向声压 环形扫描成像 

分 类 号：TB552[理学—物理] TB559[理学—声学]