Experimental and numerical studies on liquid wicking into filter papers for paper-based diagnostics

Liu, Zhi; Hu, Jie; Zhao, Yimeng; Qu, Zhiguo; Xu, Feng

doi:10.1016/j.applthermaleng.2014.09.057

Cited by 82 publications

(77 citation statements)

References 23 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We now drop the star notation that indicates a dimensionless quantity and simplify the leading-order system of equations to construct a reduced model. We first note that equations (16) and (17) are satisfied and consistent with the initial condition φ(x, z, 0) = φ 0 and boundary conditions if…”

Section: B the Dimensionless Modelmentioning

confidence: 90%

“…In this paper we study imbibition into a deformable porous substrate. The motivation behind this work stems from an industrial application, namely the absorbency of paper products used for household, medical or diagnostic applications [5,11,14,17,21,22]. Of interest is the interaction between the invading liquid and the (out-of-plane) deformation of the substrate.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Imbibition with swelling: Capillary rise in thin deformable porous media

Kvick

Martinez²,

Hewitt³

et al. 2017

Phys. Rev. Fluids

View full text Add to dashboard Cite

The imbibition of a liquid into a thin deformable porous substrate driven by capillary suction is considered. The substrate is initially dry and has uniform porosity and thickness. Two-phase flow theory is used to describe how the liquid flows through the pore space behind the wetting front when out-of-plane deformation of the solid matrix is considered. Neglecting gravity and evaporation, standard shallow-layer scalings are used to construct a reduced model of the dynamics. The model predicts convergence to a self-similar behaviour in all regions except near the wetting front, where a boundary layer arises whose structure narrows with the advance of the front. Over time, the rise height approaches the similarity scaling of t 1/2 , as in the classical 'Washburn or BCLW law'. The results are compared with a series of laboratory experiments using cellulose paper sheets, which provide qualitative agreement.

show abstract

Section: B the Dimensionless Modelmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Imbibition with swelling: Capillary rise in thin deformable porous media

Kvick

Martinez²,

Hewitt³

et al. 2017

Phys. Rev. Fluids

View full text Add to dashboard Cite

show abstract

“…Tuning capillary penetration in porous media: combining geometrical and evaporation effects. International Journal of Heat and Mass Transfer,123,[239][240][241][242][243][244][245][246][247][248][249][250] the evaporation of liquid from the surface of porous media [40,41], with particular relevance for highly volatile liquids, such as the detecting reagent, used in paper-based sensors and diagnostics [42]. Evaporation also has a significant effect on some practical respects, such as soil penetration of water in irrigation processes [43], liquid flow in fuel cells [44], and liquid transfer in capillary evaporators [45].…”

Section: A Key Factor Affecting Capillary Penetration Ismentioning

confidence: 99%

Tuning capillary penetration in porous media: Combining geometrical and evaporation effects

Liu

Gan

et al. 2018

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

Capillary penetration of liquids in porous media is of great importance in many applications and the ability to tune such penetration processes is increasingly sought after. In general, liquid penetration can be retarded or restricted by the evaporation of volatile liquid at the surface of the porous media. Moreover, when capillary penetration occurs in a porous layer with non-uniform cross section, the penetration process can be accelerated or impeded by adjusting the section geometry. In this work, on the basis of Darcy's Law and mass conservation, a theoretical model of capillary penetration combining evaporation effects in two-dimensional homogeneous porous media of varying cross-section is developed and further examined by numerical simulations. The effects of sample geometry and liquid evaporation on capillary penetration are quantitatively analyzed. Results show that the penetration velocity is sensitive to the geometry of the porous layer, and can be tuned by varying the evaporation rate for a given geometry. Under given evaporation conditions, penetration is restricted to a limited region with a predictable boundary. Furthermore, we find that the inhibition of liquid penetration by evaporation can be offset by varying the geometry of the porous layer. In addition, the theoretical model is further extended to model the capillary flow in three-dimensional porous media, and the interplay of geometry and evaporation during the capillary flow process in 3D conditions is also investigated. The results obtained can be used for facilitating the design of porous structures, achieving tunable capillary penetration for practical applications in various fields.

show abstract

“…A simple, clinical test for measuring human tear production dates back to Schirmer in 1903 [1]. As now practiced in a Schirmer tear test (STT) [2], a 0.2-mm thick paper strip (Standard Schirmer Tear Test Strip, Whatman standard filter paper # 41, Alcon Laboratories, Fort Worth, TX), 5-mm wide and 35-mm long, is folded at a notch located 5 mm from the rounded end of the strip and gently inserted into the inferior fornix (Table 1 lists pertinent properties of a standard Schirmer strip [2][3][4][5][6][7][8][9][10][11][12][13][14][15]). After 5 min of eye closure, or until the patient's tear fills the entire strip, the Schirmer strip is removed, and the wetted length beyond the notch is recorded [2].…”

Section: Introductionmentioning

confidence: 99%