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Nanoscale surface roughness affects low Reynolds number flow: Experiments and modeling
Applied Physics Letters
  • Robert Jaeger, Iowa State University
  • Jing Ren, Iowa State University
  • Yu Xie, Iowa State University
  • Sriram Sundararajan, Iowa State University
  • Michael G. Olsen, Iowa State University
  • Baskar Ganapathysubramanian, Iowa State University
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Most micro-channel fabrication strategies generate nano-to-micro-scale, stochastic surface roughness. This inherent stochasticity can potentially be harnessed to direct microfluidic operations such as self-cleaning behavior and localized mixing. This work investigates the effect of stochastic nanoscale roughness on low to moderate Reynolds number Newtonian flow using concurrent modeling and experiments. We fabricate a microscopic channel with tailored hydrofluoric-acid-etched rough surfaces. Optical profilometry and micro-particle-image-velocimetry (micro-PIV) are used to characterize the surface roughness and flow field and is integrated with direct numerical simulation that resolves effects of nanoscale roughness. Results indicate that nanoscale roughness causes flow perturbations that extend up to the mid-plane and is insensitive to flow-rates.

The following article appeared in Applied Physics Letters 101 (2012): 184102, doi:10.1063/1.4764293.

Copyright 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
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American Institute of Physics
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Robert Jaeger, Jing Ren, Yu Xie, Sriram Sundararajan, et al.. "Nanoscale surface roughness affects low Reynolds number flow: Experiments and modeling" Applied Physics Letters Vol. 101 Iss. 18 (2012) p. 184102
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