Slime logic. Who needs silicon chips?

Science Daily has a lively take on computing, with new circuits made of living slime molds:

Andrew Adamatzky (University of the West of England, Bristol, UK) and Theresa Schubert (Bauhaus-University Weimar, Germany) have constructed logical circuits that exploit networks of interconnected slime mold tubes to process information.

One is more likely to find the slime mold Physarum polycephalum living somewhere dark and damp rather than in a computer science lab. In its “plasmodium” or vegetative state, the organism spans its environment with a network of tubes that absorb nutrients. The tubes also allow the organism to respond to light and changing environmental conditions that trigger the release of reproductive spores.

In earlier work, the team demonstrated that such a tube network could absorb and transport different colored dyes. They then fed it edible nutrients — oat flakes — to attract tube growth and common salt to repel them, so that they could grow a network with a particular structure. They then demonstrated how this system could mix two dyes to make a third color as an “output.”

Using the dyes with magnetic nanoparticles and tiny fluorescent beads, allowed them to use the slime mold network as a biological “lab-on-a-chip” device. This represents a new way to build microfluidic devices for processing environmental or medical samples on the very small scale for testing and diagnostics, the work suggests.