Microfluidic co-flow of Newtonian and viscoelastic fluids for high-resolution separation of microparticles
Microfluidic co-flow of Newtonian and viscoelastic fluids for high-resolution separation of microparticles
复制标题
牛顿流体和粘弹性流体的微流体协同流动，用于微粒的高分辨率分离
DOI：
10.1039/c7lc00671c
复制
发表时间：
2017-09-21
期刊：
影响因子：
6.1
通讯作者：
Sun, Jiashu
中科院分区：
文献类型：
--
作者：
Tian, Fei;Zhang, Wei;Sun, Jiashu
微细颗粒的微流体被动控制在很大程度上依赖于牛顿流体和粘弹性流体等载体介质的流体动力学效应。然而，粘弹性/牛顿界面效应很少被研究，特别是在高分辨率颗粒分离方面。在这里，我们报告了一种牛顿流体(水或PBS)和粘弹性流体(PEO)的微流控共流，用于微粒的尺寸依赖分离。同向流动条件产生稳定的粘弹性/牛顿界面，产生与中心方向升力竞争的壁向弹性升力，并有效地阻止微粒以尺寸相关的方式从牛顿向粘弹性流体迁移。通过水和非常稀的PEO溶液(100ppm)的并流，可以几乎完全分离1微米和2微米聚苯乙烯颗粒的二元混合物，而单独使用水或PEO不能导致有效的分离。这种同向流动微流控系统也可用于分离金黄色葡萄球菌(1微米)和血小板(2-3微米)，分离效率和纯度均达到90%。
The microfluidic passive control of microparticles largely relies on the hydrodynamic effects of the carrier media such as Newtonian fluids and viscoelastic fluids. Yet the viscoelastic/Newtonian interfacial effect has been scarcely investigated, especially for high-resolution particle separation. Here we report a microfluidic co-flow of Newtonian (water or PBS) and viscoelastic fluids (PEO) for the size-dependent separation of microparticles. The co-flow condition generates a stable viscoelastic/Newtonian interface, giving rise to the wall-directed elastic lift forces that compete with the center-directed lift forces, and efficiently hinders the migration of microparticles from the Newtonian to the viscoelastic fluid in a size-dependent manner. An almost complete separation of a binary mixture of 1 mu m and 2 mu m polystyrene particles is achieved by the co-flow of water and a very dilute PEO solution (100 ppm), whereas the sole use of water or PEO could not lead to an efficient separation. This co-flow microfluidic system is also applied for the separation of Staphylococcus aureus (1 mu m) from platelets (2-3 mu m) with > 90% efficiencies and purities.