Calculating the motion of highly confined, arbitrary-shaped particles in Hele–Shaw channels

Calculating the motion of highly confined, arbitrary-shaped particles in Hele–Shaw channels

Bet, Bram (Universiteit Utrecht)
Georgiev, R.N. (TU Delft Intensified Reaction and Separation Systems; Universiteit Utrecht)
Uspal, William (Max Planck Institute for Intelligent Systems; University of Stuttgart)
Eral, H.B. (TU Delft Intensified Reaction and Separation Systems; Universiteit Utrecht)
van Roij, René (Universiteit Utrecht)
Samin, Sela (Universiteit Utrecht)

2018

We combine theory and numerical calculations to accurately predict the motion of anisotropic particles in shallow microfluidic channels, in which the particles are strongly confined in the vertical direction. We formulate an effective quasi-two-dimensional description of the Stokes flow around the particle via the Brinkman equation, which can be solved in a time that is two orders of magnitude faster than the three-dimensional problem. The computational speedup enables us to calculate the full trajectories of particles in the channel. To validate our scheme, we study the motion of dumbbell-shaped particles that are produced in a microfluidic channel using ‘continuous-flow lithography’. Contrary to what was reported in earlier work (Uspal et al. in Nat Commun 4:2666, 2013), we find that the reorientation time of a dumbbell particle in an external flow exhibits a minimum as a function of its disk size ratio. This finding is in excellent agreement with new experiments, thus confirming the predictive power of our scheme.

http://resolver.tudelft.nl/uuid:ef92f5f9-00ef-40bd-ac26-1f4f346cbf43

https://doi.org/10.1007/s10404-018-2092-y

1613-4982

Microfluidics and Nanofluidics, 22 (8)

Institutional Repository

journal article

© 2018 Bram Bet, R.N. Georgiev, William Uspal, H.B. Eral, René van Roij, Sela Samin