Gas diffusion cell geometry for a microfluidic dissolved inorganic carbon analyzer

TitleGas diffusion cell geometry for a microfluidic dissolved inorganic carbon analyzer
Publication TypeJournal Article
Year of Publication2018
AuthorsBresnahan P.J, Martz T.R
JournalIeee Sensors Journal
Date Published2018/03
Type of ArticleArticle
ISBN Number1530-437X
Accession NumberWOS:000425981100003
Keywordsacidification; anthropogenic co2; Carbon dioxide; chemical analysis; climate change; coastal; conductivity measurement; contactless conductivity detection; Engineering; flow-injection analysis; in-situ; Instruments & Instrumentation; microfluidics; ocean; physics; seawater; surface; technology; three-dimensional printing; waters

Variable gas diffusion cell geometries were tested for the extraction of dissolved inorganic carbon (DIC) from a microfluidic (tens to hundreds of microliters) seawater sample. With a focus on optimization of diffusion cell geometry, we compare five unique diffusion cell designs. Using 3-D printing technology to streamline the prototyping and testing process, we were able to conceive, design, fabricate, and thoroughly evaluate each design over the course of about one month. In total, 1043 DIC measurements were carried out in 109 experiments for the five working manifolds. We find that a small diameter, cylindrical diffusion cell design offers several advantages over its planar counterparts and a larger diameter cylindrical cell, most notably the ability to increase the ratio of the exchange membrane's contact surface area to solution volume (the "aspect ratio") without sacrificing channel integrity. Multiple designs approached short-term repeatability of <1%, but only the cylindrical diffusion cell design allowed for <0.2% repeatability using less than 200 mu L of sample.

Short TitleIEEE Sens. J.
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