Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China.
Key Laboratory of Instrumentation Science & Dynamic Measurement, North University of China, Ministry of Education, Taiyuan 030051, China.
Biosensors (Basel). 2022 Jun 10;12(6):399. doi: 10.3390/bios12060399.
As a basis for biometric and chemical analysis, issues of how to dilute or concentrate substances such as particles or cells to specific concentrations have long been of interest to researchers. In this study, travelling surface acoustic wave (TSAW)-based devices with three frequencies (99.1, 48.8, 20.4 MHz) have been used to capture the suspended Polystyrene (PS) microspheres of various sizes (5, 20, 40 μm) in sessile droplets, which are controlled by acoustic field-induced fluid vortex (acoustic vortex) and aggregate into clusters or rings with particles. These phenomena can be explained by the interaction of three forces, which are drag force caused by ASF, ARF caused by Leaky-SAW and varying centrifugal force. Eventually, a novel approach of free transition between the particle ring and cluster was approached via modulating the acoustic amplitude of TSAW. By this method, multilayer particles agglomerate with 20 μm wrapped around 40 μm and 20 μm wrapped around 5 μm can be obtained, which provides the possibility to dilute or concentrate the particles to a specific concentration.
作为生物特征和化学分析的基础，如何将颗粒或细胞等物质稀释或浓缩到特定浓度的问题一直是研究人员关注的焦点。在这项研究中，研究人员使用基于 travelling surface acoustic wave (TSAW) 的三种频率（99.1、48.8、20.4 MHz）的设备来捕获悬浮在液滴中的各种尺寸（5、20、40 μm）聚苯乙烯（PS）微球，这些液滴由声场诱导的流体涡流（声涡流）控制，并与颗粒聚集形成簇或环。这些现象可以用三种力的相互作用来解释，即 ASF 引起的阻力、漏声表面波引起的 ARF 和变化的离心力。最终，通过调节 TSAW 的声幅，实现了粒子环和簇之间的自由转换的新方法。通过这种方法，可以得到多层粒子聚集物，例如将 20 μm 的粒子包裹在 40 μm 的粒子周围，或者将 20 μm 的粒子包裹在 5 μm 的粒子周围，这为将粒子稀释或浓缩到特定浓度提供了可能。
