Electrical signal transfer characteristics of mycelium-bound composites and fungal fruiting bodies

Phillips, Neil; Weerasekera, Roshan; Roberts, Nic; Gandia, Antoni; Adamatzky, Andrew

Abstract

Mycelium-bound composites are normally made of discrete lignocellulosic substrate elements bound together by filamentous fungal hyphae. They can be formed into bespoke components of desired geometries by moulding or extrusion. Mycelium-bound composites with live fungi have been shown to be electrically conductive with memfractive and capacitive attributes. They can be integrated into electrical circuits with nonlinear electrical properties. Advancing fungal electronics, we studied the AC conductive properties of mycelium-bound composites and fungal fruit bodies at higher frequencies across three overlapping bands; 20 Hz to 300 kHz, 10 Hz to 4 MHz and 50 kHz to 3 GHz. Measurements indicate that mycelium-bound composites typically act as low-pass filters with a mean cutoff frequency of ~500 kHz; with ~ 14 dB/decade roll-off, and mean attenuation across the pass band of <1 dB. Fruiting bodies have between one or two orders of magnitude lower mean cutoff frequency (5 kHz-50 kHz depending on species); with 20 dB/decade to 30 dB/decade roll-off, and mean attenuation across the pass band of <3 dB. The mechanism for the frequency-dependent attenuation is uncertain; however, the high water content, which is electrically conductive due to dissolved ionisable solids is probably a key factor. The potential for mycelium-bound composites and fruiting bodies in analog computing is explored.

• Journal Article Type: Article
• Acceptance Date: May 13, 2024
• Online Publication Date: Jun 25, 2024
• Publication Date: Oct 1, 2024
• Deposit Date: Jul 1, 2024
• Publicly Available Date: Jul 1, 2024
• Journal: Fungal Ecology
• Print ISSN: 1754-5048
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 71
• Article Number: 101358
• DOI: https://doi.org/10.1016/j.funeco.2024.101358
• Keywords: Mycelium, Hypha, Analog, Unconventional, Edge, Biohybrid
• Public URL: https://uwe-repository.worktribe.com/output/12085482
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1754504824000291
• Additional Information: This article is maintained by: Elsevier; Article Title: Electrical signal transfer characteristics of mycelium-bound composites and fungal fruiting bodies; Journal Title: Fungal Ecology; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.funeco.2024.101358; Content Type: article; Copyright: © 2024 The Authors. Published by Elsevier Ltd.