Light‐Governed Capillary Flow in Microfluidic Systems. Issue 1 (27th September 2012)

• Record Type: Journal Article
• Authors: Jiang, Li; Erickson, David
• Is Part Of: Small. Volume 9:Issue 1(2013:Jan.)
• Page Start: 107
• Page End: 114
• Publication Date: 2012-09-27
• Subjects: Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201201778
• Languages: English
• ISSNs: 1613-6810

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>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(<italic>N</italic>‐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.</p> </abstract>