Researchers at ETH Zurich have developed an innovative living material that captures carbon dioxide (CO2) from the air, integrating conventional materials with photosynthetic cyanobacteria through interdisciplinary collaboration in biology, chemistry, and engineering.

Designed for 3D printing, this material thrives on sunlight, CO2, and artificial seawater with nutrients, positioning it as a potential building material for CO2 storage in the future.

To enhance its performance, the material was 3D printed into high-surface-area shapes, optimizing light penetration and nutrient distribution for the embedded cyanobacteria.

The hydrogel matrix not only supports the living cells but also facilitates light transmission and nutrient flow, allowing the cyanobacteria to remain effective for over a year.

The cyanobacteria absorb CO2, converting it into biomass and forming stable mineral carbonates, which provides a longer-lasting method of carbon capture than traditional biological growth.

Laboratory tests have shown that the material can bind approximately 26 mg of CO2 per gram over 400 days, significantly outperforming traditional biological methods and nearing the efficiency of chemical processes used in recycled concrete.

At the Architecture Biennale in Venice, three-meter-tall columns made from this hydrogel have been showcased, capable of capturing up to 18 kilograms of CO2 annually, comparable to the absorption capacity of a young pine tree.

This living material, which can actively sequester carbon and function similarly to trees through photosynthesis, was introduced in a study published in Nature Communications.

Researchers believe that this innovative approach could be integrated into buildings, minimizing their environmental impact throughout their lifecycle.

The vision for this living material includes its use as a coating for building façades, enabling continuous CO2 capture throughout the entire lifecycle of a structure.

In Milan, the material is being explored as a decorative coating for wood, transforming microbial growth into an aesthetically pleasing feature that is passive and scalable.

Two installations showcasing this technology have been created for the Architecture Biennale in Venice and the Triennale di Milano, actively monitoring the performance of the cyanobacteria in real-time environments.