Numerical Simulation of Electric Droplet Formation in a Flow-Focusing Microfluidic Device

Document Type : Research Article

Authors

1 School of Chemical Engineering Iran University of Science and Technology, Tehran, I.R. IRAN

2 School of Mechanical Engineering, Iran University of Science and Technology, Tehran, I.R. IRAN

Abstract

Droplet formation process is one of the most important steps in many microfluidic proceses with biological and chemical applications. Factors affecting the droplet formation process include the geometry of the device, fluid properties, operating parameters and external forces. Since the construction of many samples to optimize the microchannel geometry is required to incur heavy costs, in this study, with the help of computational fluid dynamics technique, the droplet formation process is studied. The purpose of this study is to numerically simulate flow-focusing microchannels to study microchannel dimensions and produce small droplets under the influence of an external electrical field. The innovative aspect of the present work is the study of parameters that have not been considered in open literachar. Numerical simulation of this chip was performed in two-dimensional space. According to the flow physics, the phases of the current are assumed to be incompressible. Two geometric parameters of flow concentrating region length and orifice length were investigated. The results of this study showed that for a length of 100 μm for the flow focusing region at high voltages, the droplet diameter can be reduced to less than 55 μm. The time difference between the formation of two consecutive drops for a length of 200 μm in this region at 300V increases to 0.178 seconds. It was shown that although the length of the orifice has no considerable effect on the droplet diameter, but at the length of 90 μm, droplets are formed after the orifice. It was also shown that when the distance between the electrodes is short, smaller droplets are formed due to the increase in electrical force applied to the common boundary of the two fluids. In fact, smaller droplets can be formed by selecting the appropriate configuration for the electrodes at lower voltages.

Keywords

Main Subjects

References

[1] Haghighinia A., Movahedirad S., Rezaei A.K., Mostoufi N., "On-Chip Mixing of Liquids with High-Performance Embedded Barrier Structure," International Journal of Heat and Mass Transfer, 158: 119967 (2020).
[2] Abalde-Cela S., Taladriz-Blanco P., de Oliveira M. G., Abell C., "Droplet Microfluidics for the Highly Controlled Synthesis of Branched Gold Nanoparticles," Scientific reports, 8(1): 1-6 (2018).
[3] Fery A., Dubreuil F., Möhwald H., "Mechanics of Artificial Microcapsules," New journal of Physics, 6(1): 18 (2004).
[4] Zhang X., Stefanick S., Villani F.J., "Application of Microreactor Technology in Process Development," Organic process research & development, 8(3): 455-460 (2004).
[5] Zhu P., Wang L., "Passive and Active Droplet Generation with Microfluidics: A Review," Lab on a Chip, 17(1): 34-75 (2017).
[6] Pekin D., Skhiri Y., Baret J-Ch., Le Corre D., Mazutis L., Ben Salem Ch., Millot F., El Harrak A., Brian Hutchison J.., Larson J.W.., Link D.R.., Laurent-Puig P., Griffiths A. D.., Taly V., "Quantitative and Sensitive Detection of Rare Mutations Using Droplet-Based Microfluidics," Lab on a Chip, 11(13): 2156-2166 (2011).
[7] Xi H.-D., Zheng H., Guo W., Gañán-Calvo A.M., Ai Y., Tsao Ch-W., Zhou J., Li W., Huang Y., Nguyen N-T., Tan S.H., "Active Droplet Sorting in Microfluidics: A Review," Lab on a Chip, 17(5): 751-771 (2017).
[8] Nie Zh., Seo M.S., Xu Sh., Lewis P.C.., Mok M., Kumacheva E., Whitesides G.M.., Garstecki P., Stone H.A.., "Emulsification in a Microfluidic Flow-Focusing Device: Effect of the Viscosities of the Liquids," Microfluidics and Nanofluidics, 5(5): 585-594 (2008).
[9] Gu Z., Liow J.-L., "Micro-Droplet Formation with Non-Newtonian Solutions in Microfluidic T-Junctions with Different Inlet Angles," in 2012 7th IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS), IEEE, 423-428 (2012).
[10] Sivasamy J., Wong T.-N., Nguyen N.-T., Kao L.T.-H., "An Investigation on the Mechanism of Droplet Formation in a Microfluidic T-Junction," Microfluidics and nanofluidics, 11(1): 1-10 (2011).
[11] Taassob A., Manshadi M.K.D., Bordbar A., Kamali R., "Monodisperse Non-Newtonian Micro-Droplet Generation in a Co-Flow Device," Journal of the Brazilian Society of Mechanical Sciences and Engineering, 39(6): 2013-2021 (2017).
[12] Li L. Zhang C., "Electro-Hydrodynamics of Droplet Generation in a Co-Flowing Microfluidic Device Under Electric Control," Colloids and Surfaces A: Physicochemical and Engineering Aspects, 586: 124258 (2020).
[13] Hatami M., Ramiar A., Ranjbar A.-A. J. C. E., Intensification P.-P., "Numerical Assessment of Different Parameters Affecting Droplet Production in an Electro-Hydrodynamic Flow Focusing Device," 131: 190-202 (2018).
[14] Rahimi M., Khorrami A.S., Rezai P.J.C., Physicochemical S.A., Aspects E., "Effect of Device Geometry on Droplet Size in Co-Axial Flow-Focusing Microfluidic Droplet Generation Devices," 570: 510-517 (2019).
[15] Yeh C.-H., Lee M.-H., Lin Y.-C. J. M., nanofluidics, "Using an Electro-Spraying Microfluidic Chip to Produce Uniform Emulsions Under a Direct-Current Electric Field," 12(1-4): 475-484 (2012).
[16] Tan S.H., Semin B., Baret J.-C. J. L. o. a. C., "Microfluidic Flow-Focusing in Ac Electric Fields," 14(6): 1099-1106 (2014).
[17] Li Y., Jain M., Ma Y., Nandakumar K. J. S. M., "Control of the Breakup Process of Viscous Droplets by an External Electric Field Inside a Microfluidic Device," 11(19): 3884-3899 (2015).
[18] Yin S., Huang Y., Wong T. N., Ooi K. T. J. I. J. o. M. F., "Dynamics of Droplet Formation in Flow-Focusing Microchannel under AC Electric Fields," 103212 (2020).
[19] Olsson E., Kreiss G., "A Conservative Level Set Method for Two Phase Flow," Journal of computational physics, 210(1): 225-246 (2005).
[20] Li Y., Jain M., Ma Y., Nandakumar K., "Control of the Breakup Process of Viscous Droplets by an External Electric Field Inside a Microfluidic Device," Soft Matter, 11(19): 3884-3899 (2015).
Nashrieh Shimi va Mohandesi Shimi Iran
Volume 42, Issue 4 - Serial Number 110
December 2023
Pages 205-217

Files

Share

How to cite

Statistics