Enhanced Detection in Droplet Microfluidics by Acoustic Vortex Modulation of Particle Rings and Particle Clusters via Asymmetric Propagation of Surface Acoustic Waves
Yukai Liu,
Miaomiao Ji,
Nanxin Yu,
Caiqin Zhao,
Gang Xue,
Wenxiao Fu,
Xiaojun Qiao,
Yichi Zhang,
Xiujian Chou,
Wenping Geng
Affiliations
Yukai Liu
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Miaomiao Ji
Key Laboratory of Instrumentation Science & Dynamic Measurement, North University of China, Ministry of Education, Taiyuan 030051, China
Nanxin Yu
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Caiqin Zhao
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Gang Xue
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Wenxiao Fu
School of Mechanical Engineering, North University of China, Taiyuan 030051, China
Xiaojun Qiao
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Yichi Zhang
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Xiujian Chou
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
Wenping Geng
Science and Technology on Electronic Test and Measurement Laboratory, North University of China, Taiyuan 030051, China
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.
