High-Speed Microfluidic Differential Manometer for Cellular-Scale Hydrodynamics

Division of Engineering and Applied Sciences, Harvard University, Pierce Hall, Cambridge, MA 02138, USA.
Proceedings of the National Academy of Sciences (Impact Factor: 9.67). 02/2006; 103(3):538-42. DOI: 10.1073/pnas.0507171102
Source: PubMed


We propose a broadly applicable high-speed microfluidic approach for measuring dynamical pressure-drop variations along a micrometer-sized channel and illustrate the potential of the technique by presenting measurements of the additional pressure drop produced at the scale of individual flowing cells. The influence of drug-modified mechanical properties of the cell membrane is shown. Finally, single hemolysis events during flow are recorded simultaneously with the critical pressure drop for the rupture of the membrane. This scale-independent measurement approach can be applied to any dynamical process or event that changes the hydrodynamic resistance of micro- or nanochannels.

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Available from: Magalie M. Faivre
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    • "CTA has detected differences in deformability of RBCs from healthy and diseased individuals (Baskurt et al., 1996; Koutsouris et al., 1989; Scott et al., 1993, 1992). Adaptations of this approach measure RBC deformation in capillary obstructions and tapered constrictions (Shelby et al., 2003), transit through constrictions (Gifford et al., 2006, 2003; Herricks et al., 2009a, 2009b), pressure drop while transiting constrictions (Abkarian et al., 2006), and elongation via fluid shear stress (Forsyth et al., 2010; Katsumoto et al., 2010; Lee et al., 2009). Some common limitations of these approaches are that their measures of RBC deformability do not account for variation in cell size, nor do they account for friction between the cell surface and the vessel walls (Zheng et al., 2012). "
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    ABSTRACT: A common indicator of rheological dysfunction is a measurable decrease in the deformability of red blood cells (RBCs). Decreased RBC deformability is associated with cellular stress or pathology and can impede the transit of these cells through the microvasculature, where RBCs play a central role in the oxygenation of tissues. Therefore, RBC deformability has been recognized as a sensitive biomarker for rheological disease. In the current study, we present a strategy to measure RBC cortical tension as an indicator of RBC deformability based on the critical pressure required for RBC transit through microscale funnel constrictions. By modeling RBCs as a Newtonian liquid drop, we were able to discriminate cells fixed with glutaraldehyde concentrations that vary as little as 0.001%. When RBCs were sampled from healthy donors on different days, the RBC cortical tension was found to be highly reproducible. Inter-individual variability was similarly reproducible, showing only slightly greater variability, which might reflect biological differences between normal individuals. Both the sensitivity and reproducibility of cortical tension, as an indicator of RBC deformability, make it well-suited for biological and clinical analysis of RBC microrheology.
    Full-text · Article · Apr 2014 · Journal of Biomechanics
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    • "(a) Time lapse image of a red blood cell flowing through a microchannel of comparable dimensions (e.g. Abkarian, Faivre & Stone 2006). (b) When a suspension of cells flows through a constrictions, the cells tend to drift across streamlines and away from the wall, thus concentrating towards the centre of the channel (Faivre et al. 2006). "
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    ABSTRACT: The dynamics of fluid–fluid interfaces are important in diverse problems that span many disciplines in science and engineering. A series of snapshots is used to illustrate the breadth of applications that can occur in viscous low-Reynolds-number flows and I highlight theoretical and modelling ideas that are broadly useful for these, as well as other, problems. By way of illustration of unifying quantitative ideas we discuss briefly (i) the use of the Reciprocal Theorem in low-Reynolds-number flows, (ii) the use of the lubrication approximation for characterizing thin-film coating flows sometimes referred to as Landau–Levich–Derjaguin–Bretherton problems and (iii) nearly two-dimensional viscously dominated flows.
    Preview · Article · Feb 2010 · Journal of Fluid Mechanics
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    • "Chio et al. (2006a; 2006b) showed a good agreement with predictions of a theoretical model for quasi-stationary motion of a gas bubble (Jensen et al., 2004) and their experimental works. In a contraction/expansion microchannel , Abkarian et al. (2006) showed that a stiffer red blood cell requires more pressure drop than a healthy one, which implies that a lower Ca droplet might induce additional pressure drop. In the present work, we focus on the pressure drop between the entrance and exit of the narrow channel with a finite element based front tracking method (Chung et al., 2008). "
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    ABSTRACT: The prediction of pressure drop for a droplet flow in a confined microchannel is presented using FE-FTM (Finite Element -Front Tracking Method). A single droplet is passing through 5:1:5 contraction -straight narrow channel -expansion flow domain. The pressure drop is investigated especially when the droplet flows in the straight narrow channel. We explore the effects of droplet size, capillary number (Ca), viscosity ratio (χ) between droplet and medium, and fluid elasticity represented by the Oldroyd-B constitutive model on the excess pressure drop (∆p +) against single phase flow. The tightly fitted droplets in the narrow channel are mainly considered in the range of 0.001 ≤ Ca ≤ 1 and 0.01 ≤ χ ≤ 100. In Newtonian droplet / Newtonian medium, two characteristic features are observed. First, an approximate relation ∆p + ~χ is observed for χ ≥1. The excess pressure drop necessary for droplet flow is roughly proportional to χ. Second, ∆p + seems inversely proportional to Ca, which is represented as ∆p + ~Ca m with negative m irrespective of χ. In addi-tion, we observe that the film thickness (δ f) between droplet interface and channel wall decreases with decreasing Ca, showing δ f ~ Ca n with positive n independent of χ. Consequently, the excess pressure drop (∆p +) is strongly dependent on the film thickness (δ f). The droplets larger than the channel width show enhancement of ∆p + , whereas the smaller droplets show no significant change in ∆p + . Also, the droplet deformation in the narrow channel is affected by the flow history of the contraction flow at the entrance region, but rather surprisingly ∆p + is not affected by this flow history. Instead, ∆p + is more dependent on δ f irrespective of the droplet shape. As for the effect of fluid elasticity, an increase in δ f induced by the nor-mal stress difference in viscoelastic medium results in a drastic reduction of ∆p + .
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