Citation:
S. Prentner, D.M. Allen, L. Larcombe, S. Marson, K. Jenkins and M. Saumer, Effects of channel surface finish on blood flow in microfluidic devices, Microsystem Technologies, January 2010.
Abstract:
The behaviour of blood flow in relation to microchannel surface roughness has
been investigated. Special attention was focused on the techniques used to
fabricate the microchannels and on the apparent viscosity of the blood as it
flowed through these microchannels. For the experimental comparison of smooth
and rough surface channels, each channel was designed to be 10mm long and
rectangular in cross-section with aspect ratios of â ¥100:1 for channel heights of
50 and 100μm. Polycarbonate was used as the material for the device
construction. The shims, which created the heights of the channels, were made of
polyethylene terephthalate. Surface roughnesses of the channels were varied from
Rz of 60nm to 1.8μm. Whole horse blood and filtered water were used as the test
fluids and differential pressures ranged from 200 to 5000Pa. The defibrinated
horse blood was treated further to prevent coagulation. The results indicate
that a surface roughness above an unknown value lowers the apparent viscosity of
blood dramatically due to boundary effects. Furthermore, the roughness seemed to
influence both water and whole blood almost equally. A set of design rules for
channel fabrication is also presented in accordance with the experiments
performed.
