[Paper Review] ARE SLIME MOULDS LIVING MEMRISTORS

Ella Gale, Andrew Adamatzky+1 more|arXiv (Cornell University)|Jun 14, 2013

Slime Mold and Myxomycetes ResearchEngineering23 references22 citations

TL;DR

This study demonstrates that protoplasmic tubes of the slime mould *Physarum polycephalum* exhibit current-voltage characteristics consistent with memristive behavior, suggesting they function as living memristors. The findings extend memristive properties to non-neural biological systems and support the development of self-growing bio-electronic circuits.

ABSTRACT

In laboratory experiments we demonstrate that protoplasmic tubes of acellular slime mould Physarum polycephalum show current versus voltage profiles consistent with memristive systems. This result complements previous findings on memristive properties of other living systems (human skin and blood and leaves) and contributes to development of self-growing bio- electronic circuits. Keywords: memristor, slime mould, bioelectronics

Motivation & Objective

• To investigate whether protoplasmic tubes of *Physarum polycephalum* display memristive behavior.
• To determine if the observed electrical characteristics align with the theoretical framework of memristive systems.
• To explore the potential of using living biological systems as components in bio-electronic circuits.
• To contribute to the emerging field of bio-inspired electronics by identifying new living memristive materials.

Proposed method

• Conducting laboratory experiments on isolated protoplasmic tubes of *Physarum polycephalum*.
• Measuring current-voltage (I-V) responses under controlled electrical stimulation.
• Analyzing the I-V curves for pinched hysteresis, a signature trait of memristive systems.
• Comparing the observed electrical behavior with the mathematical model of a memristor.
• Using experimental data to assess whether the system exhibits memory-dependent resistance.
• Evaluating the consistency of the I-V profiles with the defining characteristics of memristive devices.

Experimental results

Research questions

• RQ1 Do protoplasmic tubes of *Physarum polycephalum* exhibit pinched hysteresis in their current-voltage response?
• RQ2 Is the electrical behavior of these tubes consistent with the theoretical definition of a memristor?
• RQ3 Can the observed dynamics be explained by a memristive model rather than passive resistance?
• RQ4 What implications do these findings have for the design of bio-electronic circuits?
• RQ5 How do these results compare with previously reported memristive behavior in other biological systems?

Key findings

• The protoplasmic tubes of *Physarum polycephalum* displayed current-voltage profiles with pinched hysteresis, a hallmark of memristive systems.
• The observed I-V characteristics were consistent with the behavior expected from a memristor, indicating memory-dependent resistance.
• The results support the hypothesis that living biological materials can naturally exhibit memristive properties.
• This finding extends the range of known biological systems with memristive behavior beyond human skin, blood, and leaves.
• The study provides experimental evidence for the feasibility of using living protoplasmic networks as functional components in self-growing bio-electronic circuits.