“Look at the structure of conifers,” says Cordt Zollfrank, a chemist and materials scientist at the Technical University of Munich. “Plant cells are arranged in such a way that the cellulose they produce behaves in such a way that the cones close when it’s hot and dry and open on their own when it rains.” Living systems do not need energy for this. “Or take your rattan chair apart and look at the cross-section of the branches. There are tiny micrometer-sized cavities for containers. We can’t create such fine structures with a drill.” Material wonders, from coral reefs to tree trunks, have until now only been created by living cells.
While synthetic biology research teams around the world have created new synthetic microbes, modified cells or developed vaccines in recent years, others are currently fundamentally expanding the concept. Now they want to build bigger things from living cells and use them, synthetic or natural, as building materials. They design living materials – building materials grow cell by cell. These “grown materials” are fundamentally different from materials previously available. In English they are called engineering living materials or ELM for short. Unlike previous materials, they are able to multiply, to regenerate – for example by healing cracks and fissures in the material and thus the cell structure – and to respond to environmental influences.
“First we have to get the cells to arrange themselves in two and three dimensions.”
However, before researchers dare to build with bacteria on large structures such as coral structures, they must start small, very small. Seraphine Wegner, a chemist at the University of Münster, approaches the vision of the individual cell. “First we have to get the cells to arrange themselves in two and three dimensions.” In nature, stimuli such as light cause plant cells to arrange themselves in certain ways, including mechanical stimuli. Wind, for example, causes stems and trunks to become stronger.