空气中一维声栅对微粒的声操控  

Acoustic manipulation of particles by a resonant one-dimensional grating in air

作　　者：黄先玉[1,2] 蔡飞燕[2] 李文成[1] 郑海荣[2] 何兆剑[1] 邓科[1] 赵鹤平[1] 

机构地区：[1]吉首大学物理与机电工程学院,吉首416000 [2]中国科学院深圳先进技术研究院,劳特伯生物医学成像中心,深圳518055

出　　处：《物理学报》2017年第4期150-155,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11274008,11325420,11404363,11564012,11304119,11304351);深圳基础研究计划(批准号:JCYJ20150521094519482);湖南省自然科学基金(批准号:2016JJ2100);湖南省教育厅科研项目(批准号:16A170)资助的课题~~

摘　　要：本文对一维空气声栅表面微粒受到的声辐射力进行了详细的理论研究.首先采用有限元方法研究一维声栅的透射性质及表面声场分布,然后将有限元与动量张量积分结合研究处于一维声栅表面微粒受到的声辐射力特征.声栅共振透射增强是表面周期衍射波与狭缝Fabry-Perot共振耦合形成的,并且与声栅周期和厚度密切相关.研究发现,当共振波长与声栅周期相当时,微粒在其表面可受到指向声栅板面的声吸引力;当共振波长为声栅周期的二倍及以上,微粒可受到指向狭缝中的吸引力,且强度远小于第一种情况的吸引力.因此,在声栅处于共振波长与周期相当的共振模式时,可以在空气中利用声栅表面操控、吸引和排列微粒.It is well known that acoustic wave carries momentum and energy. An object in a sound field, which absorbs or reflects sound energy, can be subjected to the acoustic radiation force （ARF）, and thus can be manipulated in the contactless and noninvasive manners. This effect has potential applications in the fields of environment monitoring, microbiology, food quality control, etc. Obtaining a tunable trapping or pushing ARF should enable the design of an incident beam profile. However, the conventional acoustic manipulation system with plane wave, standing waves or Gaussian beams, which is usually generated directly by acoustic transducer, cannot be redesigned easily, nor can the corresponding ARF be modulated efficiently. Phononic crystals, which are artificial periodic structure materials, exhibit great advantages in modulating the propagation and distribution of acoustic wave compared with conventional materials, and thus have potential applications in tunable particle manipulation. Here, we present a theoretical study of the ARFs exerted on a cylindrical polystyrene foam particle near the surface of a one-dimensional （1D） grating in air. By using the finite element method （FEM） to investigate the transmission spectra and field distribution of the 1D grating and the FEM combined with momentum-flux tensor to obtain the ARF on the particle, we find that there are two resonance modes in the 1D grating, which origin from the coupling between the diffractive waves excited from the export of periodic apertures and the Fabry-Perot resonance mode inside the apertures. In addition, it can be seen from field distribution that in the first resonant mode, the resonance wavelength is approximate to the period of grating, and the enhanced spatial confinement of acoustic wave is located at the surface of the plate besides in the aperture. In the second resonant mode, the corresponding wavelength is more than twice the period of grating, and the enhanced spatial confinement of acoustic wave is mainly located in the

关 键 词：声操控 声辐射力 微粒俘获 一维声栅 

分 类 号：O42[理学—声学]