Acoustic Tweezers with Electrical Controllability on Rotation of Trapped Particle
Acoustic Tweezers with Electrical Controllability on Rotation of Trapped Particle
复制标题
具有电控捕获粒子旋转的声学镊子
DOI：
--
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
E. S. Kim
中科院分区：
文献类型：
--
作者：
Lurui Zhao;E. S. Kim
本文介绍了一种电控声镊，通过改变施加在声镊上的电压的频率，能够夹持和旋转毫米级颗粒。镊子由一对垂直放置的声学镊子组成，平行且中心对齐，使得每个镊子组的捕获区彼此重叠。每个单个换能器构建在2.03 mm厚的锆钛酸铅（PZT）基板上，该基板具有18个对称的波束成形扇区（当从顶部观察时为饼形），这些扇区被布置用于由空气腔声学透镜限定的3个焦距（17.0、18.5和20.0 mm）。从这对镊子产生的声波产生具有声能的贝塞尔光束区，其中颗粒被捕获并保持。一旦粒子被捕获，通过微调镊子的驱动频率来实现旋转操纵，这会对捕获区产生非常轻微的影响，使重力能够提供旋转被捕获粒子的不对称力。我们的实验表明，在1.17 MHz的驱动频率为两个换能器，和调谐的频率约100 Hz产生的旋转的捕获粒子的mm大小的颗粒的捕获。显示按需旋转操作在旋转mm尺寸的聚乙烯颗粒和1.3 - 1.5 mg重量的受精后24 - 36小时的斑马鱼胚胎中是有效的。
This paper describes an electrically controllable acoustic tweezers capable of holding and rotating mm-sized particles through varying the frequency of the electrical voltage applied to the tweezers. The tweezers is composed of a pair of vertically placed acoustic tweezers, in parallel and center aligned, so that the trapping zone of each of the tweezers set overlaps with each other’s. Each single transducer is built on a 2.03 mm thick lead zirconate titanate (PZT) substrate with 18 symmetric beamforming sectors (pie shaped when viewed from top) arranged for 3 focal lengths (17.0, 18.5 and 20.0 mm) defined by air-cavity acoustic lens. Acoustic waves generated from the pair of the two tweezers produce Bessel beam zone with acoustic energy well, where a particle gets trapped and held. Once a particle is captured, rotational manipulation is achieved by fine tuning the tweezers’ driving frequency, which impacts the trapping zone quite slightly, enabling gravity to provide an asymmetric force that rotates the trapped particle. Our experiments show that a trapping of mm-sized particle is achieved at 1.17 MHz driving frequency for both transducers, and tuning of the frequency by about 100 Hz generates rotation of the trapped particle. The on-demand rotational manipulation is shown to be effective in rotating mm-size polyethylene particles and 24 - 36 hours-post-fertilization zebrafish embryos that are 1.3 - 1.5 mg in weight.