期刊
ANALYTICAL CHEMISTRY
卷 93, 期 44, 页码 14667-14674出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.analchem.1c02849
关键词
-
资金
- ERDF
- Spanish Research Agency MCI [PGC2018099217-B-I00]
This paper investigates stationary electroosmotic flows of electrolytes around insulating constrictions induced by low frequency AC electric fields, introducing the concept of concentration-polarization electroosmosis. Experimental results are in qualitative agreement with the model predictions, but trapping of particles in shallow channels is also observed.
Electric fields are commonly used to trap and separate micro- and nanoparticles near channel constrictions in microfluidic devices. The trapping mechanism is attributed to the electrical forces arising from the nonhomogeneous electric field caused by the constrictions, and the phenomenon is known as insulator-based-dielectrophoresis (iDEP). In this paper, we describe stationary electroosmotic flows of electrolytes around insulating constrictions induced by low frequency AC electric fields (below 10 kHz). Experimental characterization of the flows is described for two different channel heights (50 and 10 mu m), together with numerical simulations based on an electrokinetic model that considers the modification of the local ionic concentration due to surface conductance on charged insulating walls. We term this phenomenon concentration-polarization electroosmosis (CPEO). The observed flow characteristics are in qualitative agreement with the predictions of this model. However, for shallow channels (10 mu m), trapping of the particles on both sides of the constrictions is also observed. This particle and fluid behavior could play a major role in iDEP and could be easily misinterpreted as a dielectrophoretic force.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据