Transport Network Designs Inspired by Plasmodium
> Genius is one percent inspiration, ninety-nine percent perspiration.
> I have not failed, I’ve just found 10,000 ways that won’t work.
These two quotes by Thomas Edison highlight the difficulties in making a good idea work. A good idea comes to fruition only after much hard work, but conceiving a good idea is not trivial. As one source of design ideas, biological organisms continue to provide inspiration for technological advancements that often exceed the ideas humans could conceive on their own. A recent bio-inspired design may lead to better transport networks.
Typically, transport networks refer to streets and roads designed to move commodities around, but they also include aqueducts, power lines, and Internet systems. Well-designed transport networks route the appropriate commodity (vehicles, water, electricity, information, etc.) between different nodes with high efficiency and minimal cost. Additionally, robust networks ensure accurate transfers and accommodate breakdowns along the various routes connecting the nodes.
A team of Japanese and British scientists recently discovered a correspondence between biological- and human-designed transport networks. In particular, the team studied the process by which the slime mold Physarum polycephalum (pictured below) grew to gather food.
As the slime mold grew, it formed a vein network that connected the food in a way that minimized the path lengths (and thus the cost of connecting materials). In fact, the slime mold network strongly resembled the Tokyo railway system designed to connect surrounding cities. According to the authors of the article published in Science, Physarum polycephalum “forms networks with comparable efficiency, fault tolerance, and cost to those of real-world infrastructure networks.” Though it lacks a central control structure, this single-celled organism still constructs networks rivaling the best human designs.
This research paves the way to build even better transport networks. The scientists were also able to construct a relatively simple model to describe the optimization processes utilized by the slime mold. The algorithms involved in this model provide general solutions to designing fault-tolerant networks without requiring a central control mechanism. Thus, the model provides a cost-effective way to investigate current and future transport problems.
The authors of the article attribute the self-optimization characteristics of Physarum polycephalum to evolutionary processes. However, as the design of the Tokyo rail system points to the work of a mind, so too do the elegant designs exhibited by this slime mold.