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Making a sustainable alternative to concrete from sand, gelatin and bacteria? Sounds like a fantastic idea – but one that could become reality thanks to a resourceful research team at the University of Colorado Boulder.

Concrete is the most widely produced building material in the world. Unfortunately, its production leaves a large CO₂ footprint. Researchers in the USA are therefore working on a recipe for a new living building material that has a similar strength to cement.

The unusual material consists of a mixture of sand, gelatin, growth enzymes and calcium chloride, which is poured into molds. Photosynthetic bacteria are then added to grow with the nutrients and moisture in the gel. As the material dries, the gel hardens and becomes stronger. Meanwhile, the bacteria absorb light and produce calcium carbonate, which binds the gel and sand and makes the material tougher. Blocks made of this material are tough and do not break easily. Although they are not as strong as conventional bricks, they could still be used as a sustainable building material in deserts and other regions with poor resources, for example.