TY - JOUR
T1 - Capillary driven flow of polydimethylsiloxane in open rectangular microchannels
AU - Sowers, Timothy W.
AU - Sarkar, Rohit
AU - Eswarappa Prameela, Suhas
AU - Izadi, Ehsan
AU - Rajagopalan, Jagannathan
N1 - Funding Information:
This research was based upon work supported by the National Science Foundation grants ECCS 1102201, CMMI 1400505 and DMR 1454109 and a seed grant from Arizona State University. We gratefully acknowledge the use of facilities with the LeRoy Eyring Center for Solid State Science and the Center for Solid State Electronics Research at Arizona State University. We are also thankful to Kenneth A. Brakke (Susquehanna University) for helping us with the numerical simulations in Surface Evolver.
PY - 2016
Y1 - 2016
N2 - The flow of liquid polydimethylsiloxane (PDMS, Dow Corning Sylgard 184, 10:1 base to cross-linker ratio) in open, rectangular silicon microchannels, with and without a coating (100 nm) of poly-tetra-fluoro-ethylene (PTFE), was studied. Photolithographic patterning and etching of silicon wafers was used to create microchannels with a range of widths (∼5-50 μm) and depths (5-20 μm). Experimental PDMS flow rates in both PTFE-coated and uncoated channels were compared to an analytical model based on the work of Lucas and Washburn. The experimental flow rates matched the predicted flow rates reasonably well when the channel aspect ratio (width to depth), p, was less than 2. For channels with p > 2, the observed flow rates progressively lagged model predictions with increasing p. The experimental data, including zero flow rates in certain high aspect ratio PTFE-coated channels, can largely be explained by changes in the front and upper meniscus morphology of the flow as the channel aspect ratio is varied. The results strongly suggest that meniscus morphology needs to be taken into account to accurately model capillary flow in microchannels, especially those with large aspect ratios.
AB - The flow of liquid polydimethylsiloxane (PDMS, Dow Corning Sylgard 184, 10:1 base to cross-linker ratio) in open, rectangular silicon microchannels, with and without a coating (100 nm) of poly-tetra-fluoro-ethylene (PTFE), was studied. Photolithographic patterning and etching of silicon wafers was used to create microchannels with a range of widths (∼5-50 μm) and depths (5-20 μm). Experimental PDMS flow rates in both PTFE-coated and uncoated channels were compared to an analytical model based on the work of Lucas and Washburn. The experimental flow rates matched the predicted flow rates reasonably well when the channel aspect ratio (width to depth), p, was less than 2. For channels with p > 2, the observed flow rates progressively lagged model predictions with increasing p. The experimental data, including zero flow rates in certain high aspect ratio PTFE-coated channels, can largely be explained by changes in the front and upper meniscus morphology of the flow as the channel aspect ratio is varied. The results strongly suggest that meniscus morphology needs to be taken into account to accurately model capillary flow in microchannels, especially those with large aspect ratios.
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U2 - 10.1039/c6sm00897f
DO - 10.1039/c6sm00897f
M3 - Article
AN - SCOPUS:84976892455
SN - 1744-683X
VL - 12
SP - 5818
EP - 5823
JO - Soft Matter
JF - Soft Matter
IS - 26
ER -