Light‐Governed Capillary Flow in Microfluidic Systems |
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Authors: | Li Jiang David Erickson |
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Affiliation: | Cornell University, 240 Upson Hall, Ithaca, New York 14853, USA |
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Abstract: | Light‐based flow systems for point‐of‐care devices are of interest because, in principle, sunlight could be used to operate them, potentially allowing for high functionality with minimal device complexity and expense. A light‐operated method to drive flow using poly(N‐isopropylacrylamide), a ‘smart’ polymer that changes wettability as a function of temperature, is introduced. It is grafted onto a carbon black‐polydimethylsiloxane surface, which converts light into a thermal pattern that valves flow at user‐defined locations. Flow rates are demonstrated ranging from 4 μL min?1 at 25 °C to 0.1 μL min?1 at 40 °C. The valving dynamics are also characterised, and a response time of less than 4 s is shown. Light‐operated flow could provide the simple architecture and advanced functionality needed in low‐resource point‐of‐care devices. |
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Keywords: | wetting optofluidics photochemistry point‐of‐care diagnostics microfluidics |
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