Slime mould logical gates: exploring ballistic approach

TL;DR

This paper demonstrates how the ballistic propagation of Physarum polycephalum can be harnessed to create and verify biological logical gates, which are then cascaded into a half-adder in experiments and simulations.

Contribution

It introduces a novel approach to implementing Boolean logic using Physarum's ballistic propagation, verified through experiments and simulations.

Findings

Physarum can reliably implement logical gates in laboratory settings.

The designed gates can be cascaded into a functional half-adder.

Laboratory and simulation results confirm the feasibility of biologically-based computation.

Abstract

Plasmodium of \emph{Physarum polycephalum} is a single cell visible by unaided eye. On a non-nutrient substrate the plasmodium propagates as a traveling localization, as a compact wave-fragment of protoplasm. The plasmodium-localization travels in its originally predetermined direction for a substantial period of time even when no gradient of chemo-attractants is present. We utilize this property of \emph{Physarum} localizations to design a two-input two-output Boolean logic gates $<x, y> \to <xy, x+y>$ and $<x, y> \to <x, bar{x}y>$. We verify the designs in laboratory experiments and computer simulations. We cascade the logical gates into one-bit half-adder and simulate its functionality.