Electrokinetic flow in the U-shaped micro-nanochannels

作     者：Bilong Qiu Lingyan Gong Zirui Li Jongyoon Han 

作者机构：Institute of Laser and Optoelectronic Intelligent Manufacturing College of Mechanical and Electrical Engineering Wenzhou University Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Department of Biological Engineering Massachusetts Institute of Technology 

出 版 物：《Theoretical & Applied Mechanics Letters》 (力学快报（英文版）)

年 卷 期：2019年第9卷第1期

页      面：36-42,I0005页

核心收录：

学科分类：08[工学] 0831[工学-生物医学工程（可授工学、理学、医学学位）] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0707[理学-海洋科学] 0815[工学-水利工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0813[工学-建筑学] 0802[工学-机械工程] 0824[工学-船舶与海洋工程] 0814[工学-土木工程] 0825[工学-航空宇航科学与技术] 0836[工学-生物工程] 0701[理学-数学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the Intergovernmental International Science,Technology and Innovation Cooperation Key Project of the National Key R&D Programme(2016YFE0105900) the National Natural Science Foundation of China(21576130and 11372229) Kuwait Foundation for the Advancement of Sciences(Kuwait-MIT signature project,Project code:P31475EC01) 

主　　题：U-shaped micro-nanochannels Electrokinetic flow Maximum shear stress U 

摘      要：U-shaped micro-nanochannels can generate significant flow disturbance as well as locally amplified electric field, which gives itself potential to be microfluidic mixers, electrokinetic pumps,and even cell lysis process. Numerical simulation is utilized in this work to study the hidden characteristics of the U-shaped micro-nanochannel system, and the effects of key controlling parameters(the external voltage and pressure) on the device output metrics(current, maximum values of electric field, shear stress and flow velocity) were evaluated. A large portion of current flowing through the whole system goes through the nanochannels, rather than the middle part of the microchannel, with its value increasing linearly with the increase of voltage. Due to the local ion depletion near micro-nanofluidic junction, significantly enhanced electric field(as much as 15 fold at V=1 V and P_0=0) as well as strong shear stress(leading to electrokinetic flow) is *** increasing external pressure, both electric field and shear stress can be increased initially(due to shortening of depletion region length), but are suppressed eventually at higher pressure due to the destruction of ion depletion layer. Insights gained from this study could be useful for designing nonlinear electrokinetic pumps and other systems.