Enhanced wicking dynamics of paper-based microfluidics by a nonporous wall
Journal
Physics of Fluids
Journal Volume
37
Journal Issue
2
Start Page
022034
ISSN
1070-6631
1089-7666
Date Issued
2025-02-01
Author(s)
Abstract
A paper-based microfluidic device, comprising a nonporous wall and a porous sheet separated by a gap, is investigated through many-body dissipative particle dynamics simulations. The time evolutions of the mean penetration lengths within the gap and the porous sheet are monitored separately, characterized by Lg(t) and Lp(t), respectively. They can be described by Lg2 = Sgt and Lp2 = Spt, consistent with the Lucas-Washburn equation. The influences of gap width (w) and the surface wettability of the nonporous wall (θw) on the imbibition rates Sg and Sp are systematically examined. Due to the presence of the gap, Sp is facilitated to exceed the imbibition rate of isolated paper, and Sp is always larger than Sg. It is found that Sp increases linearly with increasing w but decreases with increasing θw. The enhancement of the imbibition rate results from side imbibition, which introduces extra capillary flow from the gap to the porous sheet, in addition to the capillary flow from the bottom reservoir. The contribution from side imbibition to the liquid absorbed within the porous sheet increases over time and becomes the dominant source, surpassing the direct contribution from the bottom reservoir.
Subjects
Dissipative particle dynamics simulation
Gap widths
Lucas-Washburn equation
Many body
Microfluidics devices
Paper-based microfluidics
Penetration length
Surface wettability
Time evolutions
Wicking
Capillarity
Capillary flow
Dissipative particle dynamics
Fluidic devices
Microfluidics
Publisher
AIP Publishing
Type
journal article