File(s) under permanent embargo

Hydrodynamic flow focusing to study the isolated effects of the flow components

conference contribution
posted on 2008-01-01, 00:00 authored by F Tovar-Lopez, Khashayar Khoshmanesh, M Nasabi, K Kalantar-zadeh, G Rosengarten, A Mitchell
Biological fluids such as blood, proteins and DNA solutiosn moving within fluidic channels can potentially be exposed to high level of shear, extension or mixed stress, either in vitro such as industrial processing of blood products or in vivo such as ocurrs in some pathological conditions. This exposure to a high level of strain can trigger some reactions. In most of the cases the nature of the flow is mixed with shear and extensional components. The ability ot isolate the effects of each component is critical in order to understand the mechanisms behind the reactions and potentially prevent them. Applying hydrodynamic flow focusing, we present in this investigation the characterization of microchannels that allow study of the regions of high shear or high extension strain rate. Micro channels were fabricated in polydimethyl siloxane (PDMS)  using standard soft-lithography techniques with a photolithographically patterned mold. Characterization of the regions with high shear and high extension strain rate is presented. Computational Fluid Dynamics (CFD) simulations in three dimensions have been carried out to gain more detailed local flow information, and the results have been validated experimentally. A comparison between the numerical models and experiment and is presented. The advantages of microfluidic flow focusing in the study  of the effects of shear and extension strain rates for biological fluids are outlined.



Biomedical Applications of Micro- and Nanoengineering IV and Complex Systems. Conference (9th : 2008 : Melbourne, Victoria)


Proceedings of SPIE ; vol. 2720


SPIE: The International Society for Optical Engineering


Melbourne, Victoria

Place of publication

Bellingham, WA

Start date


End date






Publication classification

E1.1 Full written paper - refereed; E Conference publication

Copyright notice

2008, SPIE

Title of proceedings

SPIE 2008 : Progress in biomedical optics and imaging : Proceedings of SPIE Biomedical Applications of Micro- and Nanoengineering IV and Complex Systems conference