Plan cities with mold
This entry covers the use of a single cell mold, Physarum polycephalum, to create efficient infrastructure plans. Experiments have shown that it can solve a maze without even having a brain. It leaves, much like ants, a trace of where it has been before. If that trace leads to nutrition, it develops along that trace, if not, that bransch is retracted and the mold will not cover that area anymore.
The Physarum polycephalum grows as a single cell that is big enough to be seen with the naked eye. When it encounters numerous food sources separated in space, the slime mold cell surrounds the food and creates tun- nels to distribute the nutrients. An experiment was made through placing oat-flakes in a pattern that mimicked the way cities are scattered around Tokyo. The mold was then applied. Initially, the slime mold dispersed evenly around the oat flakes, exploring its new territory. But within hours, the slime mold began to refine its pattern, strengthening the tunnels between oat flakes while the other links gradually disappeared. After about a day, the slime mold had constructed a network of interconnected nutrient-ferrying tubes. Its design looked almost iden- tical to that of the rail system surrounding Tokyo, with a larger number of strong, resilient tunnels connecting centrally located oats. The researchers then borrowed simple properties from the slime mold’s behavior to create a biology-inspired mathematical description of the network formation. Like the slime mold, the model first creates a fine mesh network that goes everywhere, and then continuously refines the network so that the tubes carrying the most cargo grow more robust and redundant tubes are pruned.
Original sources: http://www.wired.com/wiredscience/2010/01/slime-mold-grows-network-just-like-tokyo-rail-system/ (Date 08/22/2013) http://www.nature.com/news/how-brainless-slime-molds-redefine-intelligence-1.11811 (Date 08/22/2013)