Researchers from the University of Colorado, Boulder have created a “living concrete” that can grow and regenerate itself. The concrete, a mixture of gelatin, sand, and cyanobacteria, is a potential breakthrough in the nascent field of self-assembling materials. The team’s research has been published in the journal Matter.
Concrete is one of the most widely used building materials in the world. For centuries, builders have been making it roughly the same way – by mixing hard materials like sand with various binders. While it has the benefits of low cost and longevity, making concrete is one of the world’s leading contributors of CO2 emissions. Researchers around the world are currently exploring alternative production methods or substitute materials that would lessen these emissions.
The Colorado scientists, working in partnership with the Department of Defense’s speculative research arm DARPA, first started with a mixture of cyanobacteria, warm water, sand, and nutrients. The process worked, but was slow, so the researchers decided to add gelatin to strengthen the matrix being built by the cyanobacteria. The gelatin provided more structure, and worked with the bacteria to help the living concrete grow stronger and faster.
The new material is capable of being regenerated from one parent “brick” using temperature and humidity switches. Splitting one brick in half and extending its shape using additional sand and hydrogel scaffolding can create three successive generation from a single parent. Unfortunately, the material is weak compared to most conventional concretes in its current form.
The research team is now working to make the material stronger for a more practical building concrete. That would involve increasing the bacteria’s resistance to dehydration or finding a different kind of cyanobacteria that doesn’t require the addition of a gel. They hope that if they can scale up the living concrete, it can use to assemble structures in remote desert areas, or potentially even in space.