Scientists at ETH Zurich have developed a new type of living material that can pull carbon dioxide (CO₂) from the air using bacteria.
This futuristic material is made with photosynthetic cyanobacteria—tiny organisms that grow inside a gel-like substance.
These bacteria use sunlight to turn CO₂ into biomass and solid minerals, capturing carbon in two different ways.
The research team, led by Professor Mark Tibbitt, created this material by mixing bacteria into a soft, printable gel called a hydrogel.
This gel lets light, water, and nutrients flow through it, allowing the bacteria to grow and thrive.
Using 3D printing, the team shaped the material into structures that maximize light exposure and nutrient flow, helping the bacteria live longer and stay active.
Cyanobacteria are some of the oldest life forms on Earth and are very good at photosynthesis.
Not only do they grow and produce biomass, but they also change the chemistry around them in a way that causes minerals—such as lime—to form. These minerals lock away CO₂ in a more stable form than biomass does.
In lab tests, the living material kept capturing CO₂ for over a year, storing around 26 milligrams of CO₂ per gram of material—much more than many current biological methods.
The bacteria also slowly harden the gel by forming minerals inside it, making the material stronger over time.
One exciting idea is to use this living material as part of buildings. It could be applied to walls or facades to help remove CO₂ from the air throughout a building’s life.
This approach uses low energy, avoids toxic chemicals, and works with natural sunlight and simple nutrients.
Researchers have already turned this idea into real-world experiments. At the Architecture Biennale in Venice, a team created large, tree-like structures using this living material.
Each one can remove up to 18 kilograms of CO₂ from the air every year—similar to what a 20-year-old pine tree does. The installations are carefully monitored to make sure the bacteria stay healthy and active.
Another project in Milan called Dafne’s Skin shows how living materials can create a beautiful green surface on wood, changing how we think about aging and decay in architecture. The green color comes from the bacteria’s chlorophyll and signals that the building material is alive and helping the planet.
Though it’s still early days, this research offers a glimpse into a future where buildings do more than just stand—they could clean the air, store carbon, and become part of nature’s solution to climate change.
