Shiitake Mushrooms Can Remember Electrical States (spectrum.ieee.org)

Researchers at Ohio State University reported that shiitake mushrooms can act as memristors—electrical components that “remember” past voltage states by changing resistance—after cultivating nine samples, drying and rehydrating them to produce moderately conductive pathways, and subjecting them to voltage, frequency, and memory tests. About 90% of samples displayed memristor-like behavior up to roughly 5.85 kHz. While far slower than silicon-based devices, shiitake’s standout properties are environmental durability (notably radiation resistance) and ready availability through existing cultivation logistics, suggesting niche applications in aerospace or medical devices where resilience and biodegradability matter rather than raw speed. The shiitake work sits alongside other provocative demonstrations of organic memristors: honey-based devices (a 2.5 μm honey dielectric with copper electrodes) switched in hundreds of nanoseconds—comparable to some inorganic memristors—though full biodegradability requires replacing copper with dissolvable metals; and preliminary tests show fresh human blood can hold altered resistance with <10% drift over 30 minutes under applied voltages. Together these studies point to a growing route for flexible, biodegradable, and harsh-environment neuromorphic components—promising for specialized sensors, implantables, and radiation-hardened circuitry in AI/ML edge systems, even if they won’t replace high-throughput silicon accelerators.