TY - JOUR
T1 - Tuning microchannel wettability and fabrication of multiple-step Laplace valves
AU - Takei, Go
AU - Nonogi, Mari
AU - Hibara, Akihide
AU - Kitamori, Takehiko
AU - Kim, Haeng Boo
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2007
Y1 - 2007
N2 - By using characteristics of titania nanoparticles, a patterning and tuning method of microchannel surface wettability was developed for microfluid control. Titania modification of a microchannel provided a nanometer-sized surface roughness and the subsequent hydrophobic treatment made the surface superhydrophobic. Photocatalytic decomposition of the coated hydrophobic molecules was used to pattern the surface wettability which was tuned in the range from superhydrophobic to superhydrophilic under controlled photoirradiation. Four-step wettability-based Laplace valves working as passive stop valves (6.8-12.5 kPa pressure barrier) were prepared by using the patterned and tuned surface. As a demonstration, a batch operation system consisting of two sub-nL dispensers and a reaction chamber was constructed. Fundamental liquid manipulations required for the batch operation were successfully conducted, including liquid measurement (390 and 770 pL), transportation, injection into the chamber, and retention in the chamber. To verify the quantitative operation, the system was applied to a fluorescence quenching experiment as an example of volumetric analyses. The present method provides flexible patterning in a wide range of tuned wettability surfaces in microchannels even after channel fabrication and it can be applied to various two- or multi-phase microfluidic systems.
AB - By using characteristics of titania nanoparticles, a patterning and tuning method of microchannel surface wettability was developed for microfluid control. Titania modification of a microchannel provided a nanometer-sized surface roughness and the subsequent hydrophobic treatment made the surface superhydrophobic. Photocatalytic decomposition of the coated hydrophobic molecules was used to pattern the surface wettability which was tuned in the range from superhydrophobic to superhydrophilic under controlled photoirradiation. Four-step wettability-based Laplace valves working as passive stop valves (6.8-12.5 kPa pressure barrier) were prepared by using the patterned and tuned surface. As a demonstration, a batch operation system consisting of two sub-nL dispensers and a reaction chamber was constructed. Fundamental liquid manipulations required for the batch operation were successfully conducted, including liquid measurement (390 and 770 pL), transportation, injection into the chamber, and retention in the chamber. To verify the quantitative operation, the system was applied to a fluorescence quenching experiment as an example of volumetric analyses. The present method provides flexible patterning in a wide range of tuned wettability surfaces in microchannels even after channel fabrication and it can be applied to various two- or multi-phase microfluidic systems.
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U2 - 10.1039/b618851f
DO - 10.1039/b618851f
M3 - Article
C2 - 17476378
AN - SCOPUS:34247873034
VL - 7
SP - 596
EP - 602
JO - Lab on a Chip - Miniaturisation for Chemistry and Biology
JF - Lab on a Chip - Miniaturisation for Chemistry and Biology
SN - 1473-0197
IS - 5
ER -