SBIR-STTR Award

The accumulation of various "greenhouse" gases, especially carbon dioxide (CO2), has accelerated in the past 50 years due to human activities in burning fossil fuels. CO2 has been known to pass into the atmosphere polluting the environment, but it has also been linked with ocean pollution as the ocean acts as a massive CO2 sink. The single most important factor in further understanding the role of oceans in the control of global warming is the capacity to make direct, in-situ measurements of CO2. No unattended, in-situ method of CO2 measurement suitable for marine applications exists. This project is to develop a CO2 sensor for the long term monitoring of CO2 in ocean waters, based on a fluorescent fiber optic sensing system. In the Phase I research program, we will concentrate on the sensor chemistry and the mechanical design of the sensor for the fluorescent fiber optic sensing system of CO2, as well as the optical and electronic systems associated with the sensor. This includes selection of the appropriate fluorescent dye molecule in the optimum buffer system and the appropriate membrane material to achieve the necessary sensitivity. The Phase II research will be a stepped-up effort of the Phase I work with regard to the longevity and the manufacturing issues, as well as the long term real time deployment of the CO2 measurement system.

Commercial Applications and Other Benefits as described by the awardee:
The success of the proposed CO2sensing system would certainly benefit the scientific community and society as it would provide a significant amount of data with regard to the relationship of CO2 to the ocean and thus methods for controlling the CO2 pollution. Furthermore, this would provide a good business opportunity, potentially up to $26 million annually. Finally, the fiber optic fluorescent CO2 measurement system could be expanded into the biotechnology and bioprocessing market by modifying some of the operational parameters.

The capacity of the oceans to absorb CO2 is not well understood. There are no long-duration, reliable sensors that can continuously monitor and measure the actual levels of dissolved CO2 in the oceans or their absorption capacity. This project will develop an optical sensing system that is suitable for the precise, reliable, long-term monitoring of CO2 in ocean waters. The sensors will be developed and field tested for long-term unattended monitoring in ocean waters. The system will interface with other environmental platforms to provide cost effective, widely dispersed monitoring of vital ocean parameters. Phase I concentrated on establishing the sensor design and secondary physical parameters that demonstrated performance in seawater at the sensitivity, resolution, and long-duration required for monitoring the CO2 flux at the air-water interface. Phase II will build a field-deployable CO2 measurement system based on a profile buoy design. This project will optimize the sensor performance characteristics, construct and deploy the buoy system for field testing, analyze data for air-sea, exchange characterization, develop accurate information on CO2 flux, provide an estimate of total inorganic carbon in the oceans based on CO2 concentration and pH measurements, and complete the design of a commercialized fiber optic sensor for CO2.

Commercial Applications and Other Benefits as described by the awardee:
The sensor should have commercial applications by combining it with a miniature fluorimeter and designing a deployable dissolved carbon dioxide sensor. This would create the ability to monitor dissolved carbon dioxide over prolonged periods of time, and would support the understanding of green house effects and as well as benefit commercial interests such as fisheries.