Micro-pHAT: A re-envisioned sensor design for measuring seawater pH and Total Alkalinity in situ

Micro-pHAT：一种重新设想的传感器设计，用于原位测量海水 pH 值和总碱度

• 批准号: 2219930
• 负责人: Ellen Briggs
• 金额: $ 45.64万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2219930&HistoricalAwards=false
• 关键词: Micro; pHAT; re; envisioned; sensor

The oceans play an integral role in the global carbon cycle and increased carbon dioxide emissions to the atmosphere have resulted in ocean warming and ocean acidification with cascading effects on marine ecosystems. Ocean-based carbon dioxide removal strategies are gaining a lot of attention and will require monitoring, reporting, and verification as well as evaluation of potential environmental impact. Traditionally, ship-based platforms have been used to collect seawater samples for benchtop analyses which has generated high quality snapshots of the ocean carbon chemistry. However, ship-based platforms are limited in their spatiotemporal resolution which has led to the development of a variety of autonomous platforms for filling in the gaps in both space and time. To date, there is no commercially available, single sensor for measuring the full seawater carbon dioxide system suitable for in situ, autonomous platforms. This project will focus on advancing the technology readiness level of a prototype sensor (Sea-pHAT) for measuring both pH and Total Alkalinity. This two-parameter sensor does not require external reagents, is low power, is fast (about 60 seconds per measurement), has a small footprint, and is solid-state all of which lend it to be suitable and ideal for in situ, autonomous platforms. This sensor is unique because most other developing technologies for measuring the seawater carbon dioxide system require reagents, have complex moving parts, and cannot measure two parameters near simultaneously. The Sea-pHAT is an ISFET-based (ion sensitive field effect transistor) pH sensor that has been modified through the addition of a coulometric actuator device to additionally perform an alkalinity titration on the chip. In its current configuration, the actuator electrode (anode) is deposited directly on the surface of the ISFET chip. We will design a microfluidic-type housing that will instead suspend the anode above the ion sensing region of the chip (gate) with adjustable vertical positioning. This has several benefits including on the fly adjustment of the anode-gate. A rigorous characterization of the anode-gate distance will be performed side-by-side with the tunable Micro-pHAT and modified ISFETs of the Sea-pHAT sensor. The optimal anode-gate distance will be determined over various ranges of AT and sensitivity of the measurement to temperature and salinity will be assessed. Signal conditioning routines will be explored to optimize the sensor output and will be integrated in the sensor software. The results from all the configurations tested will be synthesized in a user manual to aid future users in selecting optimal operating parameters and understanding system options. All of this will result in bringing us several steps closer to having a commercially available, user friendly, single dip probe for measuring the full aqueous carbon dioxide system that can be integrated on a variety of platforms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海洋在全球碳循环中起着不可或缺的作用，并增加了对大气的二氧化碳排放，导致海洋变暖和海洋酸化，并对海洋生态系统产生层叠作用。基于海洋的二氧化碳去除策略正在引起广泛关注，需要监视，报告和验证以及对潜在环境影响的评估。传统上，基于船舶的平台已用于收集海水样品进行台式分析，从而产生了海洋碳化学的高质量快照。但是，基于船舶的平台的时空分辨率受到限制，这导致了各种自主平台的发展，以填补时空和时间的空白。迄今为止，尚无商业可用的单传感器，用于测量适用于原位自主平台的全海水二氧化碳系统。该项目将着重于推进原型传感器（SEA-PHAT）的技术准备水平，以测量pH和总碱度。这个两参数传感器不需要外部试剂，低功率，快速（每次测量约60秒），具有较小的占地面积，并且是固态的，所有这些都适合其适合且非常适合原位，自主平台。该传感器是独一无二的，因为大多数其他用于测量海水二氧化碳系统需要试剂，具有复杂运动部件并且无法同时测量两个参数的开发技术。 SEA-PHAT是一种基于ISFET的（离子敏感的场效应晶体管）pH传感器，已通过添加库仪执行器设备进行了修改，以额外在芯片上执行碱度滴定。在当前配置中，执行器电极（阳极）直接沉积在ISFET芯片的表面上。我们将设计一个微流体型壳体，将其悬挂在芯片（栅极）的离子传感区域上方的阳极，并具有可调节的垂直定位。这有几个好处，包括在阳极对阳极的飞行调整。阳极距离距离的严格表征将与Sea-Phat传感器的可调节微射线和修改的ISFET并排进行。最佳阳极门距离将在AT的各个范围内确定测量对温度和盐度的敏感性。信号调节程序将探索以优化传感器输出，并将集成在传感器软件中。所有测试配置的结果将在用户手册中合成，以帮助未来的用户选择最佳的操作参数和理解系统选项。所有这些都将使我们更接近拥有商业上可用的，用户友好的单次滴探测器，用于测量可以集成在各种平台上的完整二氧化碳系统，该奖项反映了NSF的法定任务，并通过该基金会的知识分子的优点和广泛的影响来评估NSF的法定任务，并被视为值得进行的支持。