Researchers at MIT developed a new type of synthetic material that filters carbon from ambient air, using it grow, strengthen and even repair itself, much like a living plant.

The current version of the material is a synthetic gel-like substance. It performs a chemical process similar to the way plants use photosynthesis, absorbing carbon from the air to grow.

The new material is a breakthrough, because according to the researchers, carbon-fixing materials, materials that transform CO2 into a solid, stable form using only the power of the sun, did not exist until now.

“Developing a synthetic material that not only avoids the use of fossil fuels for its creation, but actually consumes carbon dioxide from the air, has obvious benefits for the environment and climate,” the researchers point out.

The material is synthetic, but the researchers did use one biological component: chloroplasts, obtained from spinach leaves. These are non-living light-harnessing components within plant cells, catalysing the reaction of carbon to glucose. On their own, chloroplasts are unstable and stop working after a few hours. However, the researchers found methods that significantly increase their lifetime. In the future, the aim is to make synthetic catalysts.

The gel matrix of the material is composed of a polymer made from aminopropyl methacrylamide (APMA) and glucose, an enzyme called glucose oxidase, in addition to the chloroplasts. As it incorporates carbon, the material becomes stronger, and could function as a crack filling or coating material.

“Our work shows that carbon dioxide need not be purely a burden and a cost,” Professor Michael Strano, one of the researchers, says. “It is also an opportunity in this respect. There’s carbon everywhere. We build the world with carbon. Humans are made of carbon. Making a material that can access the abundant carbon all around us is a significant opportunity for materials science. In this way, our work is about making materials that are not just carbon neutral, but carbon negative.”

The aim is to one day use the polymer as construction or repair material, or for protective coatings.

Image: MIT