Deep sea microfluidic sensors

The ocean, like many aquatic environments, is presently under-sampled both spatially (3D) and temporally (+1D) due to current approaches to data gathering. The current practice of sending manned missions to sea will not scale very well if we are to observe, characterize and intervene on important problems in the ocean. Unmanned water vehicles, or marine drones, offer the ability to perform remote sampling and characterization in 4D for both a) rapid response and b) large-scale persistent networks. However, equipping these marine vehicles with biogeochemical sensing capabilities is challenging since commercially available sensors are: 1) too large, 2) too expensive and 3) too energy demanding. A step-change in sensing approach is required to provide ocean chemistry and microbiology data from global observation networks. In this proposal, the utilization of microfluidic systems and lab-on-a-chip (LOC) devices will be explored for transforming current practices in acquiring ocean biogeochemical observations. Inexpensive and versatile LOC sensors will allow us to quickly, effectively, and accurately monitor ocean biogeochemistry over a wide range of deployment scenarios and across an array of locations. These microfabricated systems combine a wide-range of technologies and often integrate optics, flow control, and electronics. Microfluidic platforms naturally lend themselves toward lower reagent and power consumption, as well as reduced physical size. However, most microfluidic systems are designed for standard pressure and temperature ranges. Very few lab-on-chip systems have been designed with the intention of deployment in the deep ocean. The focus of this research program will be on creating the key microfabricated components to permit deep-ocean deployment of LOC devices. These horizontal enablers will permit several biogeochemical measurements and will unlock a scalable strategy for remote monitoring of the ocean interior. Specific outcomes will include: 1) nutrient analyzers for monitoring anthropogenic activities that have had drastic effects on the coastal ocean and climate, 2) marine microbe sensors for early-detection of harmful algal species to safeguard aquaculture investments and livelihoods, and 3) online sensors for corrosion monitoring of subsea energy production and transportation infrastructure. The developed microsensors will be integrated with autonomous water vehicles, like Argo floats and similar distributed networks, providing remote feedback on ocean chemistry and microbiology. Innovative in-situ sensors will enable us to safeguard human health, advance our knowledge of marine microbial/chemical processes, and be made aware of environmental issues before they are harmful and costly to remediate.