EPSRC-SFI: An ocean microlab for autonomous dissolved inorganic carbon depth profile measurement

EPSRC-SFI：用于自主溶解无机碳深度剖面测量的海洋微型实验室

• 批准号: EP/T016000/1
• 负责人: Paul Maguire
• 金额: $ 76.79万
• 依托单位: University of Ulster
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FT016000%2F1
• 关键词: EPSRC; SFI; ocean; microlab; autonomous

CO2 concentration in the atmosphere has increased significantly since pre-industrial times leading to global warming. There is now a major concern that ocean absorption of CO2 may be saturating, leading to more rapid global warming and much more serious consequences than predicted. Understanding the ocean CO2 system is of fundamental importance for climate change models that inform our predictions but ocean measurement of CO2, particularly in the form of dissolved inorganic carbon (DIC), is severely lacking due to technical challenges. We need regular measurements, down to a depth of 2 km, from thousands of locations world-wide. Accurate field measurements of DIC up to now have involved large and expensive surface instruments, e.g. infra-red absorption or mass spectrometry, and their miniaturisation is not feasible at the required accuracy. The aim of this project is to develop a new method of measuring DIC that is accurate, but which can also be miniaturised so that worldwide float deployment becomes a possibility. At present, the Argo network consists of ~3000 untethered battery-operated floats located across the world's oceans. They operate autonomously, drifting at a park depth of 1.5 km and every 10 days they rise to the surface, measuring the temperature and salinity depth profiles on the way. This data is then transmitted to satellite and the cycle repeats. These two parameters can be measured instantaneously at each depth whereas DIC quantification requires time-consuming chemical analysis. In the laboratory, the standard calibration technique separates DIC from seawater as CO2 gas which then transfers across a membrane into a reagent (NaOH), resulting in a decrease in conductivity. With appropriate design and calibration, the measured change in conductivity can be converted to DIC concentration. The time required for gas exchange however prevents instantaneous measurement but with the Argo float cycle, there is a 10-day park window where this exchange could be allowed to occur, and with a large number of samples. Our objectives therefore are to miniaturise each of the functional units of the laboratory setup and integrate them into a single microfluidic lab on chip which can meet the severe size, power, cost and reliability limits imposed by the Argo float integration. This presents an immense challenge; microfluidics research up to now has focussed mainly on biomedical applications which have an entirely different set of criteria, essential ocean testing of ideas and refinements is very difficult and expensive, while technical challenges can appear insurmountable. Conductivity measurement is relatively simple in concept and is readily miniaturised. However, the accuracy is much lower compared to optical techniques and this is exacerbated by the need to use extremely small sample volumes, (~100 nL). The depth resolution depends on the number of samples collected, stored, and subsequently analysed within float rise and park times respectively. The ultimate preference is ~100 samples, giving a depth resolution of 20m. This requires 100 fluid circuits and at least 100 valves to be fabricated in a 10 x 10 x 2 cm device. Such high-resolution channel patterning creates major difficulties with regards to bonding and sample leakage between channels, exacerbated by the extremely harsh environment, high pressure and the long-term deployment. This situation is further challenged by the need to seal a membrane within a multilayer structure. The best membrane materials (gas permeable and ion blocking) are very hydrophobic and resist bonding to other materials. Finally, there is no nano/micolitre valve technology that could operate in an environment where pressures vary up to 200 atmospheres. Most of the limited research to date has focussed on pneumatic valves. In this project we need to discover and develop new stimuli responsive valve materials and find a way to incorporate these into multiple microfluidic channels.

自前工业化时代以来，大气中的二氧化碳浓度显著增加，导致全球变暖。现在有一个主要的担忧是，海洋对二氧化碳的吸收可能会饱和，导致全球变暖更快，后果比预测的严重得多。了解海洋二氧化碳系统对于为我们提供预测依据的气候变化模型至关重要，但由于技术挑战，严重缺乏对二氧化碳的海洋测量，特别是以溶解无机碳(DIC)的形式。我们需要从世界各地数千个地点进行定期测量，深度可达2公里。到目前为止，DIC的精确现场测量需要使用大型且昂贵的表面仪器，例如红外吸收或质谱仪，在要求的精度下，它们的小型化是不可行的。该项目的目的是开发一种新的测量DIC的方法，该方法不仅准确，而且还可以微型化，以便在全球范围内部署浮动车成为可能。目前，ARGO网络由分布在世界各大洋的约3000个由电池供电的无绳浮标组成。它们自主运行，在公园深度1.5公里处漂流，每10天浮出水面，测量沿途的温度和盐度深度分布。然后，这些数据被传输到卫星上，重复这个周期。这两个参数可以在每个深度瞬时测量，而DIC的量化需要耗时的化学分析。在实验室中，标准校准技术将DIC以二氧化碳气体的形式从海水中分离出来，然后通过膜转移到试剂(NaOH)中，导致电导率下降。通过适当的设计和校准，可以将测量的电导率变化转换为DIC浓度。然而，气体交换所需的时间阻止了瞬时测量，但对于Argo Float循环，有一个10天的公园窗口，可以允许进行这种交换，并且有大量样本。因此，我们的目标是将实验室设置的每个功能单元小型化，并将它们集成到单个微流控芯片实验室中，以满足Argo Float集成带来的严格的尺寸、功率、成本和可靠性限制。这是一个巨大的挑战；到目前为止，微流体学研究主要集中在生物医学应用上，这些应用有一套完全不同的标准，对想法和改进进行必要的海洋测试非常困难和昂贵，而技术挑战似乎是无法克服的。电导率测量在概念上相对简单，而且很容易小型化。然而，与光学技术相比，精度要低得多，而且需要使用极小的样品体积(~100 nL)，这就加剧了这一点。深度分辨率取决于分别在浮升和停放时间内收集、存储和随后分析的样品的数量。最终选择约100个样品，深度分辨率为20m。这需要在10x10x2厘米的设备中制造100个流体回路和至少100个阀门。这种高分辨率通道图案在通道之间的结合和样品泄漏方面造成了重大困难，极端恶劣的环境、高压和长期部署加剧了这种困难。这种情况由于需要密封多层结构内的膜而进一步受到挑战。最好的膜材料(透气性和离子阻隔性)是非常疏水的，并且不会与其他材料粘合。最后，没有一种纳米/微升阀门技术可以在压力变化高达200大气压的环境中运行。到目前为止，大多数有限的研究都集中在气动阀门上。在这个项目中，我们需要发现和开发新的刺激响应性阀门材料，并找到一种方法将这些材料整合到多个微流体通道中。

项目成果

The analysis of dissolved inorganic carbon in liquid using a microfluidic conductivity sensor with membrane separation of CO2.

使用具有 CO2 膜分离功能的微流体电导率传感器分析液体中溶解的无机碳。

• DOI: 10.1007/s10404-020-02339-1
• 发表时间: 2020
• 期刊: Microfluidics and nanofluidics
• 影响因子: 2.8
• 作者: Tweedie M

Flexible Bifunctional Electrode for Alkaline Water Splitting with Long-Term Stability

• DOI: 10.1021/acsami.3c12944
• 发表时间: 2024-02
• 期刊: ACS Applied Materials & Interfaces
• 影响因子: 9.5
• 作者: Abhijit Ganguly;R. McGlynn;Adam Boies;P. Maguire;D. Mariotti;Supriya Chakrabarti

Plasma-synthesised Zinc oxide nanoparticle behavior in liquids

等离子体合成氧化锌纳米颗粒在液体中的行为

• DOI: 10.37904/nanocon.2021.4318
• 发表时间: 2021
• 作者: RUTHERFORD D

Generation and delivery of free hydroxyl radicals using a remote plasma

• DOI: 10.1088/1361-6595/acb07f
• 发表时间: 2023-01-01
• 期刊: PLASMA SOURCES SCIENCE & TECHNOLOGY
• 影响因子: 3.8
• 作者: McQuaid, H. N.;Rutherford, D.;Maguire, P. D.
• 通讯作者: Maguire, P. D.

Metered reagent injection into microfluidic continuous flow sampling for conductimetric ocean dissolved inorganic carbon sensing

将计量试剂注入微流体连续流动采样，用于电导海洋溶解无机碳传感

• DOI: 10.1088/1361-6501/ab7405
• 发表时间: 2020
• 期刊: Measurement Science and Technology
• 影响因子: 2.4
• 作者: Tweedie M