逆反射超构表面的驻波声悬浮研究

Standing wave acoustic levitation performed using retroreflection metasurface

声悬浮是一种非常重要的无接触式微粒悬浮技术,这种技术是利用声辐射力将微粒悬浮在空气中并可以用来控制微粒的运动状态.微粒在声场中的运动与声场的分布形式密切相关,由于声学超构表面的发展,声场更容易被人为调控,所以将声学超构表面引入到声悬浮技术的开发中可以将其在更多的环境中运用.本文就根据逆反射超构表面的基本理论和微粒在声场中的受力特点,数值模拟了不同入射角度下的驻波声悬浮,获得了超构表面作用下的逆反射声场和该声场中微粒随时间变化的运动状态.研究结果表明:超构表面可以用于斜入射形式下的驻波声悬浮,并且微粒在模拟中体现出了较好的声悬浮效果.从而有机会将超构表面应用到声悬浮技术中来实现特殊情况下的微粒操控,进而在医疗、化学分析和空间技术等领域发挥有益作用.

Acoustic levitation is a significant non-contact technology for suspending particles in air.This technology can suspend particles and control their motion based on the acoustic radiation force.The particle motion is closely related to the distribution of a sound field.Owing to the development of an acoustic metasurface,the sound field can be easily manipulated such that acoustic levitation can be utilized in different conditions.Based on the acoustic metasurface retroreflector theory and force on objects in the sound field,we simulate acoustic levitation with different incident angles of acoustic waves.We study the retroreflective sound field generated by a metasurface and the motion of the particles in the sound field.Our results show that the retroreflection metasurface forms a standing wave and realizes particle suspension at oblique incident angles.The application of an acoustic metasurface to acoustic levitation allows particle manipulation to be used in special conditions,which will have benefits in medical research,chemical analysis,and space technology in the future.