Vortex generation in electroosmotic flow in a straight polydimethylsiloxane microchannel with different polybrene modified-to-unmodified section length ratios
- 90 Downloads
Previous studies on electrokinetically generated vortices generally involve using relatively complicated heterogeneous surface charge patterns (with zeta potentials of different polarities). In this paper, vortex formation in a straight channel with zeta potentials of two different values, but the same polarity was investigated. Particularly, the effects of the length ratio of the polybrene (PB)-modified section to the unmodified section on vortex formation in electroosmotic flow in a straight polydimethylsiloxane (PDMS) microchannel were studied numerically and experimentally. The numerical results show that for the 5% PB-modified channel (with a zeta potential of about − 5 mV), a vortex will be formed when the length ratio of the modified section to the unmodified section was larger than 4. Such results were experimentally verified with tracing particles. The critical length ratio decreases with the decrease in the absolute value of the zeta potential of PB-modified section and increases with the increased channel width. The results presented in this paper are valuable for understanding vortex formation in a straight channel which is partially modified with PB.
KeywordsElectroosmotic vortex PDMS microchannel Polybrene Surface modification Length ratio
The authors wish to thank the financial support of the National Natural Science Foundation of China (51679023) and Liaoning BaiQianWan Talents Program to Y. Song, the Fundamental Research Funds for the Central Universities (3132018261) and the Natural Sciences and Engineering Research Council of Canada through a research grant (RGPIN-03622) to D. Li is greatly appreciated.
Compliance with ethical standards
Conflict of interest
The authors have declared no conflict of interest.
- Al-Asadi MT, Alkasmoul FS, Wilson MCT (2016) Heat transfer enhancement in a micro-channel cooling system using cylindrical vortex generators. Int Commun Heat Mass Transf 74:40–47. https://doi.org/10.1016/j.icheatmasstransfer.2016.03.002 CrossRefGoogle Scholar
- Hau WLW, Lee LM, Lee Y-K et al (2003a) Experimental investigation of electrokinetically generated in-plane vorticity in a microchannel. In: IEEE 12th international conference on transducers, solid-state sensors, actuators and microsystems, pp 651–654Google Scholar
- Hunter RJ (1981) Zeta potential in colloid science: principles and applications. Academic press, LondonGoogle Scholar
- Lee CY, Lin CF, Hung MF et al (2006) Experimental and numerical investigation into mixing efficiency of micromixers with different geometric barriers. Mater Sci Forum 505–507:391–396. https://doi.org/10.4028/www.scientific.net/MSF.505-507.391 CrossRefGoogle Scholar
- Tang LH, Chu WX, Ahmed N, Zeng M (2016) A new configuration of winglet longitudinal vortex generator to enhance heat transfer in a rectangular channel. Appl Therm Eng 104:74–84. https://doi.org/10.1016/j.applthermaleng.2016.05.056 CrossRefGoogle Scholar
- Tsai R-T, Wu C-Y (2011) An efficient micromixer based on multidirectional vortices due to baffles and channel curvature an efficient micromixer based on multidirectional vortices due to baffles and channel curvature. Biomicrofluidics 5:014103. https://doi.org/10.1063/1.3552992 CrossRefGoogle Scholar
- Wang C, Song Y, Pan X, Li D (2019) Translational velocity of a charged oil droplet close to a horizontal solid surface under an applied electric field. Int J Heat Mass Transf 132:322–330. https://doi.org/10.1016/j.ijheatmasstransfer.2018.11.127 CrossRefGoogle Scholar