Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing
Continuous and autonomous measurement of total dissolved inorganic carbon (TCO2) in the oceans is critical for modelling important climate change factors such as ocean uptake of atmospheric CO2 and ocean acidification. Miniaturised chemical analysis systems are therefore required which are small eno...
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ftdatacite:10.48550/arxiv.1909.01845 2023-05-15T17:51:56+02:00 Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing Tweedie, Mark Macquart, Antonin Almeida, Joao Ward, Brian Maguire, Paul 2019 https://dx.doi.org/10.48550/arxiv.1909.01845 https://arxiv.org/abs/1909.01845 unknown arXiv https://dx.doi.org/10.1088/1361-6501/ab7405 arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Applied Physics physics.app-ph Atmospheric and Oceanic Physics physics.ao-ph Instrumentation and Detectors physics.ins-det FOS Physical sciences article-journal Article ScholarlyArticle Text 2019 ftdatacite https://doi.org/10.48550/arxiv.1909.01845 https://doi.org/10.1088/1361-6501/ab7405 2022-03-10T16:26:40Z Continuous and autonomous measurement of total dissolved inorganic carbon (TCO2) in the oceans is critical for modelling important climate change factors such as ocean uptake of atmospheric CO2 and ocean acidification. Miniaturised chemical analysis systems are therefore required which are small enough for integration into the existing Argo ocean float network for long-term unattended depth profiling of dissolved CO2 with the accuracy of laboratory bench analysers. A microfluidic conductivity-based approach offers the potential for such miniaturisation. Reagent payload for >3 yr operation is a critical parameter. The precise injection of acid into sample, liberating CO2 from seawater, is addressed here. Laser etched microfluidic snake channel restrictors and asymmetric Y meters were fabricated to adjust the metering ratio between seawater and acid simulants. Laser etching conditions were varied to create a range of channel dimensions down to ~75 microns. Channel flow versus pressure measurements were used to determine hydrodynamic resistances which were compared with finite element simulations using a range of cross-section profiles and areas. Microfluidic metering circuits were constructed from variable resistance snake channels and dimensionally symmetric or asymmetric Y-junctions. Sample to acid volume ratios (meter ratio) up to 100:1 have been achieved with 300 microns wide snake channel for lengths > 1m. At the highest pattern resolution, this would require a footprint of > 600 mm2 (6 x10-4 m2). Circuits based solely on asymmetric Y-junctions gave meter ratios up to 16:1 with a footprint cost of < 40 mm2 and precision values of ~0.2%. Further design and fabrication refinements will be required to ensure the structural and dimensional integrity of such small channels in future integration of metering units into full TCO2 analysis microfluidic circuits. : 12 pages, 21 figures, 1 table, 3 equation images, 44 references Article in Journal/Newspaper Ocean acidification DataCite Metadata Store (German National Library of Science and Technology) |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
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language |
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Applied Physics physics.app-ph Atmospheric and Oceanic Physics physics.ao-ph Instrumentation and Detectors physics.ins-det FOS Physical sciences |
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Applied Physics physics.app-ph Atmospheric and Oceanic Physics physics.ao-ph Instrumentation and Detectors physics.ins-det FOS Physical sciences Tweedie, Mark Macquart, Antonin Almeida, Joao Ward, Brian Maguire, Paul Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
topic_facet |
Applied Physics physics.app-ph Atmospheric and Oceanic Physics physics.ao-ph Instrumentation and Detectors physics.ins-det FOS Physical sciences |
description |
Continuous and autonomous measurement of total dissolved inorganic carbon (TCO2) in the oceans is critical for modelling important climate change factors such as ocean uptake of atmospheric CO2 and ocean acidification. Miniaturised chemical analysis systems are therefore required which are small enough for integration into the existing Argo ocean float network for long-term unattended depth profiling of dissolved CO2 with the accuracy of laboratory bench analysers. A microfluidic conductivity-based approach offers the potential for such miniaturisation. Reagent payload for >3 yr operation is a critical parameter. The precise injection of acid into sample, liberating CO2 from seawater, is addressed here. Laser etched microfluidic snake channel restrictors and asymmetric Y meters were fabricated to adjust the metering ratio between seawater and acid simulants. Laser etching conditions were varied to create a range of channel dimensions down to ~75 microns. Channel flow versus pressure measurements were used to determine hydrodynamic resistances which were compared with finite element simulations using a range of cross-section profiles and areas. Microfluidic metering circuits were constructed from variable resistance snake channels and dimensionally symmetric or asymmetric Y-junctions. Sample to acid volume ratios (meter ratio) up to 100:1 have been achieved with 300 microns wide snake channel for lengths > 1m. At the highest pattern resolution, this would require a footprint of > 600 mm2 (6 x10-4 m2). Circuits based solely on asymmetric Y-junctions gave meter ratios up to 16:1 with a footprint cost of < 40 mm2 and precision values of ~0.2%. Further design and fabrication refinements will be required to ensure the structural and dimensional integrity of such small channels in future integration of metering units into full TCO2 analysis microfluidic circuits. : 12 pages, 21 figures, 1 table, 3 equation images, 44 references |
format |
Article in Journal/Newspaper |
author |
Tweedie, Mark Macquart, Antonin Almeida, Joao Ward, Brian Maguire, Paul |
author_facet |
Tweedie, Mark Macquart, Antonin Almeida, Joao Ward, Brian Maguire, Paul |
author_sort |
Tweedie, Mark |
title |
Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
title_short |
Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
title_full |
Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
title_fullStr |
Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
title_full_unstemmed |
Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
title_sort |
metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing |
publisher |
arXiv |
publishDate |
2019 |
url |
https://dx.doi.org/10.48550/arxiv.1909.01845 https://arxiv.org/abs/1909.01845 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
https://dx.doi.org/10.1088/1361-6501/ab7405 |
op_rights |
arXiv.org perpetual, non-exclusive license http://arxiv.org/licenses/nonexclusive-distrib/1.0/ |
op_doi |
https://doi.org/10.48550/arxiv.1909.01845 https://doi.org/10.1088/1361-6501/ab7405 |
_version_ |
1766159223572398080 |