Fabrication and Characterization of Teflon AF-Coated Liquid Core Waveguide Microchannels in PDMS

Chih-Wei  Wu; Yi-Lung  Lee

doi:10.6180/jase.2007.10.2.07

Fabrication and Characterization of Teflon AF-Coated Liquid Core Waveguide Microchannels in PDMS

Chih-Wei Wu This email address is being protected from spambots. You need JavaScript enabled to view it.¹ and Yi-Lung Lee¹

¹Department of Mechanical & Mechatronic Engineering, National Taiwan Ocean University, Keelung, Taiwan 202, R.O.C.

Received: February 9, 2007
Accepted: April 14, 2007
Publication Date: June 1, 2007

Download Citation: ||https://doi.org/10.6180/jase.2007.10.2.07

ABSTRACT

Nitrite ion has recently attracted a great deal of attention because of its potential roles in diverse fields of our lives. This work shows an innovative PDMS-based liquid core waveguide (LCW) to determine the concentrations of nitrite in nature water. A 1 cm straight and Teflon AF 1601S coated polydimethylsiloxane (PDMS) microchannel (600 m width and depth) replicated from a SU8 master was sealed with a glass slide with the same coating. This formed a low index of refraction microchannel in which a high index aqueous solution was flowed. Light generated by a fiber-coupled tungsten halogen lamp propagated by total internal reflection to the end of the channel where the light was detected using a CCD array spectrometer. There is a dramatic difference between channels with and without the Teflon coating. The absorbance response of this PDMS-based LCW varies linearly with concentration and adheres to Beer’s law. Additionally, calculations of absorbance using this LCW are in excellent agreement with a commercial spectrometer (JASCO, V-530). This innovative PDMSbased LCW provides a low-cost and high efficient approach to fill the inspection technology gap between in-situ and laboratory analyses. It has greater potential for development and commercialization and will be mass-produced in the future.

Keywords: Liquid Core Waveguide, Nitrite, Teflon AF 1601S

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