Electric field and viscous fluid polarity effects on capillary-driven flow dynamics between parallel plates

Rizwan Ul Hassan; Shaheer Mohiuddin Khalil; Saeed Ahmed Khan; Joonkyeong Moon; Dae-Hyun Cho; Doyoung Byun

doi:10.1016/j.heliyon.2023.e16395

Electric field and viscous fluid polarity effects on capillary-driven flow dynamics between parallel plates

Heliyon. 2023 May 19;9(6):e16395. doi: 10.1016/j.heliyon.2023.e16395. eCollection 2023 Jun.

Authors

Rizwan Ul Hassan¹, Shaheer Mohiuddin Khalil², Saeed Ahmed Khan^{2

3}, Joonkyeong Moon², Dae-Hyun Cho^{4

5}, Doyoung Byun²

Affiliations

¹ Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
² Department of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
³ Department of Electrical Engineering, Sukkur IBA University, Sukkur 65200, Pakistan.
⁴ Department of Mechatronics Engineering, Gyeongsang National University, 33 Dongjin-ro, Jinju, Gyeongsangnam-do, 52725, Republic of Korea.
⁵ Department of Energy System Engineering, Gyeongsang National University, 501 Jinjudae-ro, Jinju, Gyeongsangnam-do, 52828, Republic of Korea.

Abstract

-Micropumps have attracted considerable interest in micro-electro-mechanical systems (MEMS), microfluidic devices, and biomedical engineering to transfer fluids through capillaries. However, improving the sluggish capillary-driven flow of highly viscous fluids is critical for commercializing MEMS devices, particularly in underfill applications. This study investigated the behavior of different viscous fluid flows under the influence of capillary and electric potential effects. We observed that upon increasing the electric potential to 500 V, the underfill flow length of viscous fluids increased by 45% compared to their capillary flow length. To explore the dynamics of underfill flow under the influence of an electric potential, the polarity of highly viscous fluids was altered by adding NaCl. The results indicated an increase of 20-41% in the underfill flow length of highly viscous conductive fluids (0.5-4% NaCl additives in glycerol) at 500 V compared to that at 0 V. The underfill viscous fluid flow length improved under the electric potential effect owing to the polarity across the substance and increased permittivity of the fluid. A time-dependent simulation, which included a quasi-electrostatic module, level set module, and laminar two-phase flow, was executed using the COMSOL Multiphysics software to analyze the effect of the external electric field on the capillary-driven flow. The numerical simulation results agreed well with the experimental data, with an average deviation of 4-7% at various time steps for different viscous fluids. Our findings demonstrate the potential of utilizing electric fields to control the capillary-driven flow of highly viscous fluids in underfill applications.

Keywords: Electric potential; Underfill flow; Viscous fluids.