超声换能器的超构透镜设计与制备  

Design and fabrication of metalens for ultrasonic transducers

作　　者：朱志强[1] 安志武[2] 李威[3] ZHU Zhiqiang;AN Zhiwu;LI Wei(Liaoning University of Technology,Jinzhou 121001,China;State Key Laboratory of Acoustics and Marine Information,Institute of Acoustics,Chinese Academy of Sciences,Beijing 100190,China;Tianjin University,Tianjin 300072,China)

机构地区：[1]辽宁工业大学,锦州121001 [2]中国科学院声学研究所声学与海洋信息全国重点实验室,北京100190 [3]天津大学,天津300072

出　　处：《应用声学》2025年第2期513-518,共6页Journal of Applied Acoustics

基　　金：国家自然科学基金项目(12334019)。

摘　　要：高强度聚焦超声是一种新型的体外无创治疗肿瘤技术。为实现超声的超近聚焦,现有的方法主要为超声聚焦透镜或超声相控阵。超声聚焦透镜多为凹面镜,其表面的非平面结构会加强空化效应,进而损害透镜,缩短其使用寿命,且非平面结构不利于换能器表面与机体的耦合。超声相控阵为多阵元编程控制,存在阵元一致性差和栅瓣角度过小而进入目标范围等问题。为此,该文提出通过超构材料构建超声透镜(超构透镜),实现超声换能器的超近聚焦,即通过不同超构结构的相位延迟作用,实现不同位置处超声信号的相位调制,进而实现超近聚焦效果。该文利用上述方案设计制备了1MHz的超声换能器,并测得超构透镜的F数(聚焦深度与孔径之比)为2.5,与几何超声透镜相当。该文工作可为新型超声聚焦换能器的开发提供参考。High intensity focused ultrasound(HIFU)is a novel non-invasive tumor treatment technology per formed outside the body.To achieve super-close focusing,existing methods include ultrasound focusing lenses and ultrasound phased arrays.Ultrasound focusing lenses are mostly concave mirrors,their non-planar surface structures may intensify cavitation effects and damage the lenses,shortening their service life,and the non planar structures are not conducive to the coupling between the transducer surface and the body.The phased array of ultrasound is a multi-source programming control,and there are problems such as poor consistency of the sources and too small grating lobe angle entering the target range.Therefore,this paper proposes to build an ultrasound lens through metamaterials to achieve the super-close focusing of the ultrasound transducer(Metalens),that is,by the phase delay action of different metamaterial structures,the phase modulation of ultrasound signals at different positions is realized,thereby achieving the super-close focusing effect.Based on a 1 MHz ultrasound transducer,the specific scheme design was carried out,and the F-Number(focusing depth-to-aperture ratio)is 2.5,which is comparable to the geometric ultrasound lens.This work may provide a reference for the development of new ultrasonic focusing transducers.

关 键 词：高强度聚焦超声 超近聚焦 超构材料 超构透镜 

分 类 号：TB552[理学—物理]