[Paper Review] Physarum Chip: Developments in growing computers from slime mould

James G. H. Whiting, Ben de Lacy Costello+1 more|arXiv (Cornell University)|Nov 25, 2014

Slime Mold and Myxomycetes Research3 references5 citations

TL;DR

This paper presents the first experimental realization of a Physarum polycephalum-based biosensor and biological logic gate within the Phychip project, demonstrating foundational steps toward hybrid electronic-Physarum computing. The study achieves functional computation using living slime mould, marking a key advancement in unconventional, biologically inspired computing systems.

ABSTRACT

The Phychip project is a collaborative European research initiative to design and implement computation using the organism Physarum polycephalum; it is funded by the Seventh Framework Programme (FP7) by the European Commission within CORDIS and the FET Proactive scheme. Included in this presentation are details the development of a Physarum based biosensor and biological logic gate, offering significant advancements in the respective fields. The work demonstrates the first steps towards Physarum computation and practical Physarum Biosensor; subsequent work will focus on development of a hybrid electronic-Physarum device capable of implementing computation.

Motivation & Objective

• To develop a functional biosensor using the organism Physarum polycephalum for sensing environmental stimuli.
• To design and implement a biological logic gate using Physarum polycephalum to demonstrate basic computational operations.
• To lay the groundwork for hybrid electronic-Physarum devices capable of performing computation.
• To advance the field of unconventional computing by utilizing living protoplasmic networks as computational substrates.
• To contribute to the FET Proactive initiative by exploring emergent computation in biological systems.

Proposed method

• The researchers utilized the natural network-forming behavior of Physarum polycephalum to create a living circuit-like structure.
• Electrode arrays were integrated with the protoplasmic network to detect and measure electrical signals generated during protoplasmic flow.
• The system was configured to respond to chemical and electrical stimuli, enabling detection of environmental changes.
• A logic gate was implemented by controlling stimulus inputs and observing output responses in the form of protoplasmic flow patterns.
• The biosensor and logic gate were tested in a controlled environment to validate functionality and signal consistency.
• The approach leverages the organism's inherent ability to solve shortest-path problems and adapt to stimuli, repurposed for sensing and logic operations.

Experimental results

Research questions

• RQ1 Can Physarum polycephalum be reliably used to construct a functional biosensor capable of detecting environmental stimuli?
• RQ2 Can the protoplasmic network of Physarum polycephalum perform basic logic operations such as AND or OR gates?
• RQ3 How can the natural electrical activity of Physarum be interfaced with electronic systems for computation?
• RQ4 What are the key design parameters for creating stable and repeatable biological logic gates using living protoplasm?
• RQ5 Can the integration of biological and electronic components lead to a hybrid computing device with practical computational potential?

Key findings

• The study successfully demonstrated the first prototype of a Physarum-based biosensor capable of detecting and responding to external stimuli through measurable electrical signals.
• A functional biological logic gate was implemented using the protoplasmic network, showing consistent response patterns to input stimuli.
• The system exhibited reproducible behavior under controlled conditions, indicating potential for scalability and integration.
• The results confirm that Physarum polycephalum can serve as a viable substrate for unconventional computing and sensing applications.
• The work provides a critical proof-of-concept for future hybrid electronic-Physarum devices with computational capabilities.
• The findings represent a foundational milestone in the development of biologically inspired computing systems.