Quantification of Vortex Generation Due to Non-Equilibrium Electrokinetics at the Micro/Nanochannel Interface: Particle Tracking Velocimetry

Micromachines

Tae-Joon Jeon¹  Sun Min Kim²  Kilsung Kwon³  Daejoong Kim³  Seung Jun Lee³ 

[1] Department of Biological Engineering, Inha University, Incheon 22212, Korea;Department of Mechanical Engineering, Inha University, Incheon 22212, Korea;Department of Mechanical Engineering, Sogang University, Seoul 04107, Korea;

关键词: vortex generation;    nanochannel;    microparticle;    particle tracking velocimetry;   

DOI  :  10.3390/mi7070127

来源: DOAJ

【 摘 要 】

We describe a quantitative study of vortex generation due to non-equilibrium electrokinetics near a micro/nanochannel interface. The microfluidic device is comprised of a microchannel with a set of nanochannels. These perm-selective nanochannels induce flow instability and thereby produce strong vortex generation. We performed tracking visualization of fluorescent microparticles to obtain velocity fields. Particle tracking enables the calculation of an averaged velocity field and the velocity fluctuations. We characterized the effect of applied voltages and electrolyte concentrations on vortex formation. The experimental results show that an increasing voltage or decreasing concentration results in a larger vortex region and a strong velocity fluctuation. We calculate the normalized velocity fluctuation—whose meaning is comparable to turbulent intensity—and we found that it is as high as 0.12. This value is indicative of very efficient mixing, albeit with a small Reynolds number.

【 授权许可】

Unknown