There's mushroom for improvement in fungal computing

Ohio State boffins coax shiitake and button varieties into behaving like memristors

US boffins claim early tests indicate edible mushrooms can function as organic memory devices, though significant challenges remain before the lab experiment can be turned into something practical.

Researchers at Ohio State University say they cultivated and "trained" shiitake and button mushrooms to act as memristors – electronic components that retain information about previous electrical states.

By connecting custom circuits to dehydrated fungal samples, they say they replicated the memory behavior typically seen in semiconductor components.

"We would connect electrical wires and probes at different points on the mushrooms because distinct parts have different electrical properties," said John LaRocco, lead author of the study, who is a research scientist in psychiatry at Ohio State's College of Medicine.

The mushroom-based memristors achieved switching frequencies up to 5,850 times per second with approximately 90 percent accuracy – though performance degraded at higher frequencies. This leaves a substantial gap between fungal circuits and commercial silicon chips, which operate at billions of cycles per second.

The researchers found that connecting multiple fungi together improved stability, creating networks they compared to neural connections in the brain. We're not sure about this comparison and would prefer a second opinion from the British Association for Cognitive Neuroscience, if BACN and mushrooms can be brought together.

While these organic memristors can't yet compete with silicon chips in raw performance, they offer advantages in energy efficiency and sustainability.

"Being able to develop microchips that mimic actual neural activity means you don't need a lot of power for standby or when the machine isn't being used," said LaRocco.

"That's something that can be a huge potential computational and economic advantage."

Unlike semiconductors, which require mined minerals and energy-intensive manufacturing, fungal materials are biodegradable and naturally decomposable, cheap and easy to cultivate and potentially scalable from small-scale ops to industrial production.

Such organic memristors are still at an early stage of development, the researchers concede. Achieving smaller, more efficient fungal components will be key to making them viable alternatives to microchips, but if they can be made to work well, the world could be your oyster.

Fungal electronics are not an entirely new idea. In fact, The Register has previously reported on schemes using them as sensors to measure how people walk and a mycelium network acting as a computing device. ®