Experimental Investigation and Simulation of Controlled Size Droplet Formation in a Capillary Microdevice

Document Type : Article

Authors

1 PhD Student of Faculty of Mechanical Engineering, University of Tehran, Tehran, Iran

2 Bachelor Student of Faculty of Mechanical Engineering, University of Tehran, Tehran, Iran

3 Associate Professor of Faculty of Mechanical Engineering, University of Tehran, Tehran, Iran

10.24200/j40.2024.64794.1714

Abstract

This study focuses on the precise production of droplets in a droplet-based microfluidic device, where monodisperse oil-in-water emulsions with controlled droplet sizes are generated. The primary objective is to achieve uniform emulsions by examining key parameters such as additives in the continuous aqueous phase, internal phase flow rates, and the microfluidic device's geometric characteristics. Initially, the geometric parameters of the microchip for emulsion formation were selected using numerical simulations, and the results were validated through experimental tests of emulsion production with the microchip. The precision of the outcomes is enhanced using an innovative 3D printing method for microchip manufacturing, enabling the creation of identical microdevice copies. In the experimental phase, the optimal conditions for producing uniform droplets were identified by examining the effects of various additives in the external aqueous phase, different internal phase flow rates, and the geometric parameters of the microfluidic device. The results demonstrate that the distance between the two capillaries can control droplet size and frequency, the internal phase flow rate, and the type of additive in the external phase, allowing for emulsions with droplet sizes ranging from 500 to 1000 microns. Specifically, the distance between the capillary tubes significantly affects droplet size, contributing to 30% of the variation when this distance is increased sixfold. Additionally, the study reveals that the increase in droplet diameter due to a higher internal phase flow rate varies with different additives in the external phase. For instance, sodium dodecyl sulfate (SDS) results in a 6.65-fold increase in droplet production frequency with a sixfold increase in the internal phase flow rate. Furthermore, the type of additive in the external phase can independently control droplet size. For example, with a specific internal-to-external phase ratio, oil droplets measure 600.8 μm in an external phase containing SDS, 582.2 μm with polyvinyl alcohol (PVA), and 615.4 μm with Triton X-100. This method can precisely control droplet size and frequency, making it suitable for generating precursor emulsions for engineered micro- and millimeter-sized polymer particles aimed at drug delivery or cell culture applications. The study successfully ensures consistent and uniform emulsions by manipulating these critical parameters through this combined approach of numerical simulations and experimental validation.

Keywords

Main Subjects

References

1. Shum, H. C., Rowat, A. C., Lee, D., Agresti, J. J., Utada, A. S., and Weitz, D. A. (2008). Designer emulsions using microfluidics. Materials Today, 11(4), 18–27. https://doi.org/10.1016/S1369-7021(08)70053-1 2. Maan, A. A., Schroën, K., and Boom, R. (2011). Spontaneous droplet formation techniques for monodisperse emulsions preparation – Perspectives for food applications. Journal of Food Engineering, 107(3–4), 334–346. https://doi.org/10.1016/J.JFOODENG.2011.07.008. 3. Umbanhowar, P. B., Prasad, V., and Weitz, D. A. (1999). Monodisperse Emulsion Generation via Drop Break Off in a Coflowing Stream. Langmuir, 16(2), 347–351. https://doi.org/10.1021/LA990101E 4. Zhu, P., Tang, X., & Wang, L. (2016). Droplet generation in co-flow microfluidic channels with vibration. Microfluidics and Nanofluidics, 20(3), 1–10. https://doi.org/10.1007/S10404-016-1717-2/FIGURES/5 5. Dewandre, A., Rivero-Rodriguez, J., Vitry, Y., Sobac, B., and Scheid, B. (2020). Microfluidic droplet generation based on non-embedded co-flow-focusing using 3D printed nozzle. Scientific Reports 2020 10:1, 10(1), 1–17. https://doi.org/10.1038/s41598-020-77836-y 6. Erkal, J. L., Selimovic, A., Gross, B. C., Lockwood, S. Y., Walton, E. L., McNamara, S., Spence, D. M. (2014). 3D printed microfluidic devices with integrated versatile and reusable electrodes. Lab on a Chip, 14(12), 2023–2032. https://doi.org/10.1039/C4LC00171K 7. Venzac, B., Deng, S., Mahmoud, Z., Lenferink, A., Costa, A., Bray, F., and Le Gac, S. (2021). PDMS Curing Inhibition on 3D-Printed Molds: Why? Also, How to Avoid It? Analytical Chemistry, 93(19), 7180–7187. https://doi.org/10.1021/acs.analchem.0c04944 8. Vedhanayagam, A., Golfetto, M., Ram, J. L., and Basu, A. S. (2023). Rapid Micromolding of Sub-100 µm Microfluidic Channels Using an 8K Stereolithographic Resin 3D Printer. Micromachines, 14(8), 1519. https://doi.org/10.3390/MI14081519/S1 9. Wu, L., Qian, J., Liu, X., Wu, S., Yu, C., and Liu, X. (2023). Numerical Modelling for the Droplets Formation in Microfluidics - A Review. Microgravity Science and Technology 2023 35:3, 35(3), 1–21. https://doi.org/10.1007/S12217-023-10053-0 10. Hernández-Cid, D., Pérez-González, V. H., Gallo-Villanueva, R. C., González-Valdez, J., and Mata-Gómez, M. A. (2022). Modeling droplet formation in microfluidic flow-focusing devices using the two-phases level set method. Materials Today: Proceedings, 48, 30–40. https://doi.org/10.1016/J.MATPR.2020.09.417 11. Oveysi, M., Karim Khani, M. M., Bazargan, V., Nejat, A., and Marengo, M. (2024). Multiple emulsions: A new level-set based two-and-three dimensional simulation of multiphase immiscible flows for droplet formation. International Journal of Multiphase Flow, 170, 104645. https://doi.org/10.1016/J.IJMULTIPHASEFLOW.2023.104645 12. Yu, W., Liu, X., Zhao, Y., and Chen, Y. (2019). Droplet generation hydrodynamics in the microfluidic cross-junction with different junction angles. Chemical Engineering Science, 203, 259–284. https://doi.org/10.1016/J.CES.2019.03.082 13. Nabavi, S. A., Vladisavljević, G. T., Gu, S., and Ekanem, E. E. (2015). Double emulsion production in glass capillary microfluidic device: Parametric investigation of droplet generation behaviour. Chemical Engineering Science, 130, 183–196. https://doi.org/10.1016/J.CES.2015.03.004 14. Nabavi, S. A., Vladisavljević, G. T., Bandulasena, M. V., Arjmandi-Tash, O., and Manović, V. (2017). Prediction and control of drop formation modes in microfluidic generation of double emulsions by single-step emulsification. Journal of Colloid and Interface Science, 505, 315–324. https://doi.org/10.1016/J.JCIS.2017.05.115 15. Brackbill, J. U., Kothe, D. B., & Zemach, C. (1992). A continuum method for modeling surface tension. Journal of Computational Physics, 100(2), 335–354. https://doi.org/10.1016/0021-9991(92)90240-Y 16. Raad, M., Rezazadeh, S., Jalili, H., and Abbasinezhad Fallah, D. (2021). A numerical study of droplet splitting in branched T-shaped microchannel using the two-phase level-set method. Advances in Mechanical Engineering, 13(11). https://doi.org/10.1177/16878140211045487/ASSET/IMAGES/LARGE/10.1177_16878140211045487-FIG17.JPEG 17. Pan, X., Wang, Y., and Shen, M. (2022). A conservative level set approach to non-spherical drop impact in three dimensions. Micromachines 2022, Vol. 13, Page 1850, 13(11), 1850. https://doi.org/10.3390/MI13111850 18. Hu, Q., Jiang, T., and Jiang, H. (2020). numerical simulation and experimental validation of liquid metal droplet formation in a co-flowing capillary microfluidic device. Micromachines 2020, Vol. 11, Page 169, 11(2), 169. https://doi.org/10.3390/MI11020169 19. M. J. Rosen, and J. T. Kunjappu. (2012). Surfactants and Interfacial Phenomena (4th ed.). Hoboken, New Jersey: John Wiley and Sons., 4, 33–34. Retrieved from https://doi.org/10.1002/9781118228920. 20. Hunger, Klaus. (2003). Industrial dyes : chemistry, properties, applications. Wiley-VCH. https://doi.org/10.1002/3527602011. 21. Trinh, T. N. D., Do, H. D. K., Nam, N. N., Dan, T. T., Trinh, K. T. L., and Lee, N. Y. (2023). Droplet-Based Microfluidics: Applications in Pharmaceuticals. Pharmaceuticals 2023, Vol. 16, Page 937, 16(7), 937. https://doi.org/10.3390/PH16070937 22. Amirifar, L., Besanjideh, M., Nasiri, R., Shamloo, A., Nasrollahi, F., De Barros, N. R., and Khademhosseini, A. (2022). Droplet-based microfluidics in biomedical applications. Biofabrication, 14(2), 022001. https://doi.org/10.1088/1758-5090/AC39A9
Sharif Journal of Mechanical Engineering
Volume 40, Issue 2 - Serial Number 2
December 2024
Pages 76-84

Files

Share

How to cite

Statistics