Thanks to a semitropical frog species, energy from the sun and carbon from the air are being converted to sugars, which in turn can be turned into new forms of biofuels. In naturally occurring photosynthesis, plants take in solar energy and carbon dioxide and convert it to oxygen and sugars. The oxygen is released to the air, and the sugars are dispersed throughout plants. University of Cincinnati researchers are finding ways to take energy from the sun and carbon from the air to create new forms of biofuels, thanks to a semitropical frog species. Illustration by Megan Gundrum, a fifth-year student in the University of Cincinnati's College of Design, Art, Architecture and Planning. Engineering researchers from the University of Cincinnati focused on making a new (and more efficient) artificial photosynthetic material that uses plant, bacterial, frog and fungal enzymes, trapped within a foam housing, to produce sugars from sunlight and carbon dioxide. The team included assistant professor David Wendell, student Jacob Todd and College of Engineering and Applied Science Dean Carlo Montemagno. Foam was chosen because it can effectively concentrate the reactants but allow very good light and air penetration. The design was based on the foam nests of a semitropical frog called the Tungara, which creates very long-lived foams for its developing tadpoles. "The advantage for our system compared to plants and algae is that all of the captured solar energy is converted to sugars, whereas these organisms must divert a great deal of energy to other functions to maintain life and reproduce," Wendell said. "Our foam also uses no soil, so food production would not be interrupted, and it can be used in highly enriched carbon dioxide environments, like the exhaust from coal-burning power plants, unlike many natural photosynthetic systems. In natural plant systems, too much carbon dioxide shuts down photosynthesis, but ours does not have this limitation due to the bacterial-based photocapture strategy." There are many benefits to being able to create plantlike foam. "You can convert the sugars into many different things, including ethanol and other biofuels," Wendell explained. "And it removes carbon dioxide from the air but maintains current arable land for food production." "This new technology establishes an economical way of harnessing the physiology of living systems by creating a new generation of functional materials that intrinsically incorporates life processes into its structure," said Montemagno. "Specifically, in this work it presents a new pathway of harvesting solar energy to produce either oil or food with efficiencies that exceed other biosolar production methodologies. More broadly, it establishes a mechanism for incorporating the functionality found in living systems into systems that we engineer and build." The next step will be trying to make the technology feasible for large-scale applications such as carbon capture at coal-burning power plants. "This involves developing a strategy to extract both the lipid shell of the algae (used for biodiesel) and the cytoplasmic contents (the guts), and reusing these proteins in the foam," Wendell said. "We are also looking into other short carbon molecules we can make by altering the enzyme cocktail in the foam." "It is a significant step in delivering the promise of nanotechnology," Montemagno said. For more information, visit: www.uc.edu/news
Photosensitizers