Logic Circuit Built with Living Slime Molds
The Earth is filled with an almost unimaginable variety of organisms, from majestic elephants and whales, to slime molds. With the proper ingenuity, we can put these organisms and their special abilities to use in unexpected ways. As reported by Elsevier, researchers have successfully built logic circuits with slime mold networks.
Physarum polycephalum typically inhabits dark and damp areas, and when it is in its plasmodium state, the slime mold will stretch a network of tubes across its environment. These tubes are meant to bring nutrients into the mold, but they also allow it to respond to environmental conditions and release spores. By placing nutrients to attract and salt to repel the tubes, the researchers were able to control the structure of the network as it grew. They then gave the mold dyes, which they have previously shown it could absorb and transport, which contained magnetic nanoparticles and fluorescent beads, creating a biological lab-on-a-chip device.
By increasing the size of the network it should be possible to have the slime mold network perform the complex Boolean operations, and already XOR and NOR have been demonstrated. While it is unlikely we will see slime-based computers in the future, this could help merge materials science, computer science, and biology.