Scientists Are Turning Shiitake Mushrooms Into Computers

If you think about it in the broadest possible terms, a computer is effectively just a handful of rocks that we've successfully tricked into "thinking." With the human brain as a model and a healthy dose of electricity, quite a few natural substances can be transformed into a living network. Researchers have even managed to fuse mushrooms with robots. Case in point, in a recent study published in PLOS One, a team of researchers out of The Ohio State University have successfully turned a gaggle of shiitake mushrooms into a genuine computing system.

The researchers grew a small colony of shiitake in petri dishes, and when they matured, hooked them up to an electrical circuit. Shiitake was chosen in particular due to the fungi's natural affinity for and resistance to electrical impulses. The result of this odd little network was a series of natural memory resistors, or "memristors" for short. Much like the neurons in your brain, the mushrooms were able to switch states when exposed to different voltages and frequencies of electricity. Remarkably, these mushroom memristors were able to switch states with an efficacy comparable to that witnessed in some of the earliest silicon-based memristors, which form the basis of most major modern computing frameworks. Because the mushrooms are organic, they can become naturally resistant to electrical impulses, adjusting to them naturally just like a neuron.

Using a colony of carefully dried shiitake mushrooms, the researchers created an entire computational circuit, with discs of shiitake acting as the circuit's nodes. This circuit was able to memorize and deliver electrical impulses with impressive accuracy after some training, all in a process not dissimilar to how fungal colonies stretch underground via mycelium tendrils.

In theory, if these mushroom computers could be sufficiently sized down, they could provide a myriad of benefits. For instance, shiitake is quite literally dirt-cheap to grow and care for, and is naturally biodegradable compared to the metallic waste produced by junked rare earth element electrical components. Shiitake is also naturally resistant against the forces of oxidation and radiation, healing itself when damaged by either, which could make shiitake-based memristors invaluable for aerospace research purposes like the new rockets we're sending to Mars.

At the current stage, the researchers' paper is merely a proof of concept. We won't have mushroom-based computers any time soon, with the primary hitch being the aforementioned sizing-down necessary to fully replace mineral-based semiconductors. Still, the science is absolutely there, and with sufficient research, we could very well live in a world where our electronic devices grow and decompose with age, which would also save us the effort of repurposing our old phones.

"By testing devices produced to physical stress conditions, a combination of these techniques could enable the development of fast, radiation-resistant, and low-energy memristors grown from low-cost organic materials," the researchers write in their paper. "The future of computing could be fungal."