Scientists are turning to an organism as mindless and humble as slime mould to devise the ideal infrastructure networks for modern society.

Scientists around the world are closely studying the structures that slime moulds create during the process of growth and expansion, using that for inspiration and reference material for the development of optimum-efficiency transportation networks in the modern world.

Scientists believe one species of slime mould in particular, Physarum polycephalum (the “multi-headed slime”), is best suited to the creation of network structures which solve the spatial design dilemmas that confront human transport planners.

The plasmodial, single-celled organism commences its growth from an initial point of origin by sending out multiple tendrils in search of sources of nourishment. Once the locations of different sustenance points are determined, however, all but the most efficient links between them then wither away and perish, leaving behind the optimum spatial network for connecting the various nodes.

This process of “biomimicry” also possesses the advantages of economy and speed. Under ideal growing conditions, slime moulds can expand at a rate of one centimetre an hour, meaning that they can solve the spatial conundrums of real-life rail and road networks in a matter of days.

slime infrastructure

When the researchers place food at cities on the map, the fungus collaborates, spreading out to map many possible configurations and then dying away to highlight the shortest routes between cities and the most efficient overall system map.

These organic simulations of infrastructure networks are also highly dynamic and reactive, because they consist of a single, integrated “supercell,” in which events in one part of its anatomy influence the development of the rest of the structure.

When contingencies such as crashes or natural disasters are simulated by adding salt, which is toxic to the slime mould, to any part of the network, the rest of the organism will respond by bulking up other links or creating new ones. This in turn provides transportation planners with essential cues on how to respond to traffic emergencies.

Scientists from Japan’s University of Hokkaido first used slime mould to map out the optimum network for Tokyo’s underground in 2010 by using flakes of oatmeal meticulously placed on a Petri dish to represent the Japanese capital’s various subway stations.

An international team of scientists under the leadership of Professor Andrew Adamatzky, director of the unconventional computing centre from the University of the West of England, has since used the method to conduct a comparison of the road networks of 14 different countries and regions, including Africa, Australia, Belgium, Brazil, Canada, China, Germany, Iberia, Italy, Malaysia, Mexico, the Netherlands, the UK and the US.

Their study has produced some surprising findings. Belgium, Canada and China were host to the transport networks which most closely mimicked the optimum efficiency structures laid out by the ravenous slime moulds in their Petri dish simulations.

Networks in the United States and the African continent proved to be the least efficient, however, while those in the UK also left much to be desired.

According to the slime mould’s growth patterns, the M4 motorway between Bristol and London would be better placed in the West Midlands, while the M6/M74 should connect London to Glasgow by passing through the east via Newcastle, instead of traversing the west coast.