STTR Phase I: Self-powered underwater light system for photosynthetic cultures

The broader impact/commercial potential of this project is to transform the culture of photosynthetic aquatic microorganisms. Although microalgae and cyanobacteria have high volumetric productivities, the cultures cannot be too deep, due to restrictions of light penetration. This proposed technology removes the light penetration limit inherent in current technologies. The results of this project will allow the production of medical and food grade biomass in controlled conditions, as the light source will not be connected to the exterior of the culture reactors. This approach will provide the advantages of a fermentation production using phototrophic species, without the need to supply organic carbon. The photosynthetic biomass production makes use of carbon dioxide and light for growth. This project will result in a microalgal/cyanobacterial biomass production in areas where it is not currently feasible and with higher productivity. The increase of the depth of the cultures two, five or more times of what is currently possible, practically reduces the area required for biomass production. A reduction of cost will improve the economic outlook for microalgal-based commodity products, including feed, food, fuels, nutraceuticals and pharmaceuticals and lower the environmental impact. This Small Business Technology Transfer (STTR) Phase I project addresses one of the most significant problems found in achieving the promise of microalgae and cyanobacteria as source of food, fuels and other products is the limitation of light penetration. Most outdoor cultures are limited to less than 60 cm depth. In reactors with artificial light, besides the light penetration high electrical costs limit their use to high value products. This project will result in a light system that takes advantage of the water movement in cultures to generate electricity for LED lights in untethered units that move with the culture. The proposed generator uses methods more efficient and lighter that traditional electromagnetic and piezoelectric generators. The developed energy harvester can be used in other applications such as power for water quality monitoring and other sensing equipment. In this phase, a unit with a miniaturized energy harvester coupled with passive switching, charging, discharging and rectifying modules in the same substrate, in a waterproof casing will be developed. Data proof of the suitability of these units to support photosynthetic microorganisms? biomass production will be obtained. The results will inform further development of the units in a future phase. 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.