This startup thinks slime mold can help us design better cities

Officially known as vizarm polycephalum, Slime mold is neither a plant, nor an animal, nor a fungus. Rather, it is a single-celled organism older than dinosaurs. When searching for food, it extends tentacle-like protrusions in multiple directions at once. It then doubles down on the most efficient paths that lead to food while abandoning less productive paths. This process creates improved networks that balance efficiency and flexibility, a quality required in transportation and infrastructure systems.

An organism’s ability to find the shortest path between multiple points while maintaining backup connections has made it a favorite among researchers studying network design. Most famously, in 2010, researchers at Hokkaido University announced the results of an experiment in which they dropped a mass of slime mold onto a detailed map of Tokyo’s railway system, with major stations marked with oat flakes. First, the mindless organism overran the entire map. Days later, it scaled back, leaving behind only the most efficient tracks. The result closely reflects Tokyo’s actual railway network.

Since then, researchers around the world have used slime molds to solve mazes and even map the dark matter that holds the universe together. Experts across Mexico, Great Britain and the Iberian Peninsula have tasked the organism with redesigning their methods – although few of these experiments have translated into real-world improvements.

Historically, researchers working with the organism would print out a physical map and add slime mold to it. But Kay believes Merita’s approach, which mimics the construction of slime mold pathways without the need for actual organisms, could help solve more complex problems. Slime molds are visible to the naked eye, so Kay’s team studied how the blobs behave in the lab, focusing on the key behaviors that make these organisms so good at creating efficient networks. They then translated these behaviors into a set of rules that became an algorithm.

Some experts are not convinced. According to Jeff Boeing, an associate professor in the Department of Urban Planning and Spatial Analysis at the University of Southern California, such algorithms do not address “the messy realities of getting into a room with a group of stakeholders and jointly planning the future of their community.” He says modern urban planning problems are not just technical issues: “It’s not that we don’t know how to make infrastructure networks efficient, resilient and connected – it’s that doing so is politically challenging.”