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Microfluidic detection and analysis by integration of thermocapillary actuation with a thin-film optical waveguide

Valentino, Joseph P. and Troian, Sandra M. and Wagner, Sigurd (2005) Microfluidic detection and analysis by integration of thermocapillary actuation with a thin-film optical waveguide. Applied Physics Letters, 86 (18). Art. No. 184101. ISSN 0003-6951.

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We demonstrate a nonintrusive optical method for microfluidic detection and analysis based on evanescent wave sensing. The device consists of a planar thin-film waveguide integrated with a microfluidic chip for directed surface flow. Microliter droplets are electronically transported and positioned over the waveguide surface by thermocapillary actuation. The attenuated intensity of propagating modes is used to detect droplet location, to monitor dye concentration in aqueous solutions, and to measure reaction rates with increasing surface temperature for a chromogenic biochemical assay. This study illustrates a few of the capabilities possible by direct integration of optical sensing with surface-directed fluidic devices.

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Troian, Sandra M.0000-0003-1224-6377
Additional Information:©2005 American Institute of Physics (Received 12 January 2005; accepted 28 March 2005; published online 25 April 2005) This work was funded by the NASA Microgravity Fluid Physics Program and the US Army TACOM-ARDEC. One of the authors (J.P.V.) thanks Dr. P. K. Tien of Bell Labs for helpful discussions. SMT gratefully acknowledges the hospitality and financial support of the Moore Distinguished Scholar Program at the California Institute of Technolgy.
Subject Keywords:microfluidics; micro-optics; microactuators; thin film devices; optical sensors; microsensors; optical planar waveguides; drops; capillarity; dyes; reaction rate constants
Issue or Number:18
Record Number:CaltechAUTHORS:VALapl05
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4959
Deposited By: Archive Administrator
Deposited On:15 Sep 2006
Last Modified:09 Mar 2020 13:19

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