Determining the variation and distribution of chemical species within the oceans is fundamental to understanding the biogeochemical cycles that underpin elemental transport and biological productivity across the globe. Traditionally most chemical parameters (e.g. nitrate, phosphate) are measured by laboratory analysis of discrete water samples. Microfluidic sensors offer an attractive alternative: by taking and analysing samples autonomously in situ, they obviate sampling allowing larger datasets particularly when used in conjunction with autonomous systems.The current state-of-the-art sensors have temporal resolution of minutes due to Taylor dispersion (fluid flow effectively smears chemical composition within the device) making them unsuitable for deployments requiring high frequency measurement – most notably on profiling vehicles (e.g. Argo floats, oceanic gliders) that rapidly transect the water column. Droplet microfluidics (in which nanolitre water samples are taken and subsequently operated on as droplets within an immiscible oil) is a novel microfluidic method that, in addition to other advantages, crucially offers zero Taylor dispersion and much higher analytical throughput. This project will develop the first-ever droplet-flow based field-deployable sensor for autonomous systems. Low-cost, low-powered and fully functional; the device will be a step-change in high-frequency autonomous ocean chemical analysis.
If you wish to discuss any details of the project informally, please contact Dr. Xize Niu, Email: [email protected] , Tel: +44 (0) 2380 59 2367.