利用人工结构实现有限衍射声束及其对颗粒操纵的实验研究

As a contactless particles manipulation method and it unique advantages, acoustic radiation force has been becoming a research hotspot in the field of physics. Conventional sound beams only implement particles transport along a straight line, recent theoretical researches discover that a class of non diffracted beam can overcome this limitation and is expected to realize particle bending transport and acceleration and etc. However, the experiment fabrication of this acoustic beam by traditional methods has become a big problem. This project is based on the new concept of acoustic artificial structure, by use of novel structures such as acoustic metamaterials, metasurface, gradient structure and quasi-like periodic, aiming to experimentally realize limited diffraction beams such as Bessel beam, Airy beam and vortex beam, and then to study its mechanics effects on particles including positive or negative radiation force by the momentum and the torque by the orbital angular momentum of the beam, and finally to experimentally realize particles manipulation such as trapping, dragging and pulling, bending and acceleration motion by applying the constructed limited diffraction beams. The research of this project can not only provide a new method to realize the limited diffraction beams, and can also offer a new way of particles manipulation. Meanwhile, the project may also have potential prospect of applications, e.g. target transport of drugs, medical imaging, tissue characterization and so on.

声辐射力作为一种无接触的颗粒操纵手段及其独特优势，一度成为物理学界的研究热点。传统的声束只能实现粒子沿直线传输，最近理论发现，一类无衍射束可克服这一局限，有望实现粒子的曲线及加速运动等。然而利用传统的方法从实验上构造该类声束成为一大难题。本项目立足于声学人工结构新概念，利用声学超材料、超表面、梯度结构及类准周期等新颖结构从实验上实现有限衍射声束（如贝塞尔束、艾里束及涡旋束等），并研究该有限衍射声束的动量和轨道角动量对颗粒的正或负辐射力、力矩等力学效应，进一步利用构建的有限衍射声束实验上实现对粒子的俘获、拖拽、曲线及加速运动等操纵。本项目的研究不仅能提供有限衍射声束的构建新方法，而且能提供颗粒操控的新途径，同时还可能具有潜在应用如药物的定点传送、医学成像、组织定征等。

本项目通过设计并制备声人工结构实现了有限衍射声束，并利用该声束实现了对颗粒的操纵，主要研究内容包括：利用声学超材料、超表面、梯度结构等新颖结构从实验上实现有限衍射声束（如贝塞尔束、艾里束及涡旋束等），研究该有限衍射声束的动量和轨道角动量对颗粒的正或负辐射力、力矩等力学效应，并进一步利用构建的有限衍射声束实验上实现了对粒子的俘获、拖拽、曲线及加速运动等操纵。对本项目的研究取得了一些有意义的研究成果。到目前为止，在该基金支持下，已发表SCI论文15篇，包括Nature Physics 1篇，Phys. Rev. Applied 1篇，Phys. Rev. B & E 2篇， Appl. Phys. Lett. 6篇及Adv. Mater. Technol.1篇。