Semi-tropical frogs help scientists devise foam that removes excess CO2

Engineers from the University of Cincinnati, US, have devised a foam that captures energy and removes excess carbon dioxide (CO2) from the air - all thanks to semi-tropical frogs.

In natural photosynthesis, plants take in solar energy and carbon dioxide and then convert it to oxygen and sugars.

The oxygen is released to the air and the sugars are dispersed throughout the plant.

Unfortunately, the allocation of light energy into products we use is not as efficient as we would like.

Now, engineering researchers at the University of Cincinnati are finding ways to take energy from the sun and carbon from the air to create new forms of biofuels, with help from a semi-tropical frog species.

Their work focused on making a new artificial photosynthetic material which uses plant, bacterial, frog and fungal enzymes, trapped within a foam housing, to produce sugars from sunlight and carbon dioxide.

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 semi-tropical frog called the Tungara frog, 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," said Research assistant professor David Wendell.

"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," he added.

"In natural plant systems, too much carbon dioxide shuts down photosynthesis, but ours does not have this limitation due to the bacterial-based photo-capture strategy," he said.

There are many benefits to being able to create a plant-like 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," he added.

"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 College of Engineering and Applied Science Dean Carlo 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," he said.