Wittmann Leonie, Krucker-Velasquez Emily, Schaupp Julia, Westphal Laura, Swan James W, Alexander-Katz Alfredo, Bazant Martin Z, Schwaminger Sebastian P, Berensmeier Sonja
Technical University of Munich, TUM School of Engineering and Design, Chair of Bioseparation Engineering, Boltzmannstr. 15, 85748 Garching, Germany.
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nanoscale. 2025 Jan 16;17(3):1574-1584. doi: 10.1039/d4nr02225d.
This work explores the complex hydrodynamics in magnetophoretic microfluidic processes, focusing on the interplay of forces and particle concentrations. The study employs a combined simulation and experimental approach to investigate the impact of magnetophoresis on magneto-responsive nanoparticles (MNPs) and their environment, including non-magneto-responsive nanoparticles (non-MNPs) in a microfluidic system. Our findings reveal that the motion of MNPs induces a hydrodynamic convective motion of non-MNPs, significantly affecting the separation efficiency and purity of the particles. The separation efficiency of MNPs increases with the Péclet number, reflecting the increase in the magnetophoretic force, but decreases with lower concentrations. Conversely, non-MNPs exhibit high and constant separation efficiency with increasing Péclet number, independent of the magnetophoretic force. In a mixture, the separation efficiency of non-MNPs decreases, suggesting that non-MNPs drag along MNPs. The Mason number, representing the ratio between shear and magnetophoretic force, also plays a crucial role in the separation process. The results underscore the need for careful control and optimization of the Péclet and Mason numbers, as well as particle concentrations, for efficient magnetophoretic microfluidic processes. This study provides valuable information on the underlying principles of magnetophoresis in microfluidic applications, with implications for biochemistry, biomedicine, and biotechnology.
这项工作探索了磁泳微流体过程中的复杂流体动力学，重点关注力与粒子浓度之间的相互作用。该研究采用模拟与实验相结合的方法，来研究磁泳对微流体系统中磁响应纳米粒子（MNPs）及其环境（包括非磁响应纳米粒子（非MNPs））的影响。我们的研究结果表明，MNPs的运动会引发非MNPs的流体动力对流运动，这对粒子的分离效率和纯度有显著影响。MNPs的分离效率随佩克莱数增加，这反映了磁泳力的增加，但在较低浓度下会降低。相反，非MNPs随着佩克莱数增加呈现出高且恒定的分离效率，与磁泳力无关。在混合物中，非MNPs的分离效率会降低，这表明非MNPs会拖拽MNPs。代表剪切力与磁泳力之比的梅森数在分离过程中也起着关键作用。结果强调了为实现高效磁泳微流体过程，需要仔细控制和优化佩克莱数、梅森数以及粒子浓度。这项研究为微流体应用中磁泳的基本原理提供了有价值的信息，对生物化学、生物医学和生物技术具有重要意义。
