This paper examines the ability to measure the
velocity of both physiological saline (PS) and in vitro blood in a
rectangular polydimethysiloxane (PDMS) microchannel by
means of the confocal micro-PIV system. The PDMS microchannel,
was fabricated by conventional soft lithography, had
a microchannel near to a perfect rectangular shape (300μm
wide, 45μm deep) and was optically transparent, which is
suitable to measure both PS and in vitro blood using the confocal
system. By using this latter combination, the measurements
of trace particles seeded in the flow were performed for both
fluids at a constant flow rate (Re=0.021). Generally, all the
velocity profiles were found to be markedly blunt in the central
region mainly due to the low aspect ratio (h/w=0.15) of the
rectangular microchannel. Predictions by a theoretical model
for the rectangular microchannel have showed fairly good
correspondence with the experimental micro-PIV results for
the PS fluid. Conversely, for the in vitro blood with 20%
haematocrit, small fluctuations were found on velocity profiles.This study was supported in part by the following grants: International Doctoral Program in Engineering from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT), “Revolutionary Simulation Software (RSS21)” next-generation IT program of MEXT; Grants-in-Aid for Scientific Research from MEXT and JSPS Scientific Research in Priority Areas (768) “Biomechanics at Micro- and Nanoscale Levels,” Scientific Research (A) No.16200031 “Mechanism of the formation, destruction, and movement of thrombi responsible for ischemia of vital organs.” The authors also thank all members of Esashi, Ono and Tanaka Lab. for their assistance in fabricating the PDMS microchannel
