Computing to get slimy?

Were you aware that Bristol’s University of the West of England (UWE) has a Professor of Unconventional Computing?

Professor Andrew Adamatzky (for it is he! Ed.) and a German colleague have recently been engaged in some interesting research according to a UWE press release.

Professor Andrew Adamatzky and Theresa Schubert (Bauhaus-University Weimar, Germany) have constructed logical circuits that exploit networks of interconnected slime mould tubes to process information.

The slime mould involved – Physarum polycephalum – is more likely to be found living somewhere dark and damp rather than in a computer lab. In its vegetative state, the organism spans its environment with a network of nutrient-absorbing tubes. 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 coloured 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 colour as an “output”.

Using the dyes with magnetic nanoparticles and tiny fluorescent beads allowed them to use the slime mould network as a biological “lab-on-a-chip” device. The work suggests this represents a new way to build micro-fluidic devices for processing environmental or medical samples on the very small scale for testing and diagnostics. The extension to a much larger network of slime mould tubes could process nanoparticles and carry out sophisticated Boolean logic operations of the kind used by computer circuitry. The team has so far demonstrated that a slime mould network can carry out XOR or NOR Boolean operations. Chaining together arrays of such logic gates might allow a slime mould computer to carry out binary operations for computation.

“The slime mould based gates are non-electronic, simple and inexpensive, and several gates can be realized simultaneously at the sites where protoplasmic tubes merge,” conclude Adamatzky and Schubert.

Stewart Bland, Editor of Materials Today (in which Adamatzky’s and Schubert’s research is published. Ed.), believes that “although more traditional electronic materials are here to stay, research such as this is helping to push and blur the boundaries of materials science, computer science and biology, and represents an exciting prospect for the future.”