Living computers powered by mushrooms

Mushrooms are known for their toughness and unusual biological properties, qualities that make them attractive for bioelectronics. This emerging field blends biology and technology to design innovative, sustainable materials for future computing systems.

Turning Mushrooms Into Living Memory Devices

Researchers at The Ohio State University recently discovered that edible fungi, such as shiitake mushrooms, can be cultivated and guided to function as organic memristors. These components act like memory cells that retain information about previous electrical states.

Their experiments showed that mushroom-based devices could reproduce the same kind of memory behavior seen in semiconductor chips. They may also enable the creation of other eco-friendly, brain-like computing tools that cost less to produce.

"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 John LaRocco, lead author of the study and a research scientist in psychiatry at Ohio State's College of Medicine. "That's something that can be a huge potential computational and economic advantage."

The Promise of Fungal Electronics

LaRocco noted that fungal electronics are not a brand-new idea, but they are becoming increasingly practical for sustainable computing. Because fungal materials are biodegradable and inexpensive to produce, they can help reduce electronic waste. In contrast, conventional semiconductors often require rare minerals and large amounts of energy to manufacture and operate.

"Mycelium as a computing substrate has been explored before in less intuitive setups, but our work tries to push one of these memristive systems to its limits," he said.

The team's findings were published in PLOS One.

How Scientists Tested Mushroom Memory

To test their capabilities, researchers grew samples of shiitake and button mushrooms. Once matured, they were dehydrated to preserve them and then attached to custom electronic circuits. The mushrooms were exposed to controlled electric currents at different voltages and frequencies.

"We would connect electrical wires and probes at different points on the mushrooms because distinct parts of it have different electrical properties," said LaRocco. "Depending on the voltage and connectivity, we were seeing different performances."

Surprising Results from Mushroom Circuits

After two months of testing, the researchers found that their mushroom-based memristor could switch between electrical states up to 5,850 times per second with about 90% accuracy. Although performance decreased at higher electrical frequencies, the team noticed that connecting multiple mushrooms together helped restore stability -- much like neural connections in the human brain.

Qudsia Tahmina, co-author of the study and an associate professor of electrical and computer engineering at Ohio State, said the results highlight how easily mushrooms can be adapted for computing. "Society has become increasingly aware of the need to protect our environment and ensure that we preserve it for future generations," said Tahmina."So that could be one of the driving factors behind new bio-friendly ideas like these."

Building on the flexibility mushrooms offer also suggests there are possibilities for scaling up fungal computing, said Tahmina. For instance, larger mushroom systems may be useful in edge computing and aerospace exploration; smaller ones in enhancing the performance of autonomous systems and wearable devices.

Looking Ahead: The Future of Fungal Computing

Although organic memristors are still in their early stages, scientists aim to refine cultivation methods and shrink device sizes in future work. Achieving smaller, more efficient fungal components will be key to making them viable alternatives to traditional microchips.

"Everything you'd need to start exploring fungi and computing could be as small as a compost heap and some homemade electronics, or as big as a culturing factory with pre-made templates," said LaRocco. "All of them are viable with the resources we have in front of us now."

Other Ohio State contributors to the study include Ruben Petreaca, John Simonis, and Justin Hill. The research was supported by the Honda Research Institute.