Liu Yue, Zhou Yuying, Zhang Wenchang, Chen Shaohua, Liang Shengfa
School of Instrumentation Science & Opto Electronics Engineering, Beijing Information Science and Technology University, Beijing 100101, P. R. China.
School of Integrated Circuits, University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi. 2024 Oct 25;41(5):919-925. doi: 10.7507/1001-5515.202401076.
Ultrasonic microfluidic technology is a technique that couples high-frequency ultrasonic excitation to microfluidic chips. To improve the issues of poor disturbance effects with flexible tip structures and the susceptibility of bubbles to thermal deformation, we propose an enhanced ultrasonic microchannel structure that couples flexible tips with bubbles aiming to improve the disturbance effects and the stability duration. Firstly, we used finite element analysis to simulate the flow field distribution characteristics of the flexible tip, the bubble, and the coupling structure and obtained the steady-state distribution characteristics of the velocity field. Next, we fabricated ultrasonic microfluidic chips based on these three structures, employing 2.8 μm polystyrene microspheres as tracers to analyze the disturbance characteristics of the flow field. Additionally, we analyzed the bubble size and growth rate within the adhering bubbles and coupling structures. Finally, we verified the applicability of the coupling structure for biological samples using human red blood cells (RBCs). Experimental results indicated that, compared to the flexible tip and adhering bubble structures, the flow field disturbance range of the coupling structure increased by 439.53% and 133.48%, respectively; the bubble growth rate reduced from 14.4% to 3.3%. The enhanced ultrasonic microfluidic structure proposed in this study shows great potential for widespread applications in micro-scale flow field disturbance and particle manipulation.
超声微流控技术是一种将高频超声激发与微流控芯片相结合的技术。为改善柔性尖端结构干扰效果不佳以及气泡易受热变形影响的问题，我们提出了一种将柔性尖端与气泡相结合的增强型超声微通道结构，旨在提高干扰效果和稳定持续时间。首先，我们使用有限元分析来模拟柔性尖端、气泡及耦合结构的流场分布特性，并获得了速度场的稳态分布特性。接下来，我们基于这三种结构制作了超声微流控芯片，采用2.8μm聚苯乙烯微球作为示踪剂来分析流场的干扰特性。此外，我们分析了附着气泡和耦合结构内气泡的大小及生长速率。最后，我们使用人红细胞（RBC）验证了耦合结构对生物样品的适用性。实验结果表明，与柔性尖端结构和附着气泡结构相比，耦合结构的流场干扰范围分别增加了439.53%和133.48%；气泡生长速率从14.4%降至3.3%。本研究提出的增强型超声微流控结构在微尺度流场干扰和颗粒操控方面具有广泛应用的巨大潜力。
