Jump to main content
Jump to site search

Issue 15, 2014
Previous Article Next Article

Optimized cross-slot microdevices for homogeneous extension

Author affiliations

Abstract

Microfluidic cross-slot devices can generate wide regions of vorticity-free strong extensional flow near the stagnation point, resulting in large extensional deformation and orientation of the microstructure of complex fluids, with possible applications in extensional rheometry and hydrodynamic stretching of single cells or molecules. Standard cross-slot devices, with sharp or rounded corners, generate a flow field with a non-homogeneous extension rate that peaks at the stagnation point, but decays significantly with distance from the stagnation point. To circumvent this limitation, an optimized shape cross-slot extensional rheometer (OSCER) was designed numerically and shown to generate constant extension rate over a wide region of the in- and out-flowing symmetry planes [Haward et al., Phys. Rev. Lett., 2012, 109, 128301]. Since the OSCER device was based on a 2D flow approximation, the practical implementation requires a large aspect ratio, which cannot be reproduced by standard soft-lithography techniques. Here, we propose a set of new designs for optimized cross-slot geometries, considering aspect ratios of order 1 and different lengths of the homogeneous inlet/outlet-flow regions. Micro-particle image velocimetry experiments were carried out in order to validate the flow kinematics, and the velocity profiles were found to be linear along the in- and outflow centrelines in good quantitative agreement with the numerical predictions.

Graphical abstract: Optimized cross-slot microdevices for homogeneous extension

Back to tab navigation

Supplementary files

Publication details

The article was received on 02 Dec 2013, accepted on 02 Jan 2014 and first published on 06 Jan 2014


Article type: Paper
DOI: 10.1039/C3RA47230B
Citation: RSC Adv., 2014,4, 7799-7804
  •   Request permissions

    Optimized cross-slot microdevices for homogeneous extension

    F. J. Galindo-Rosales, M. S. N. Oliveira and M. A. Alves, RSC Adv., 2014, 4, 7799
    DOI: 10.1039/C3RA47230B

Search articles by author

Spotlight

Advertisements