Can Mushrooms Really Function Like Computer Memory?

Researchers grew shiitake mycelium into disk-like samples, attached ordinary electrodes and test equipment, and measured memristive behavior: the material’s present resistance depended partly on the electrical signals it had previously received.

They then placed two fungal samples in a simple circuit with an Arduino, a relay, and a voltage divider to test a form of volatile memory. The fungus supplied the unusual electrical behavior; conventional electronics supplied the power, switching, measurement, and control.

That distinction matters. The experiment demonstrated a biological component that could participate in a memory circuit—not a standalone computer made entirely from mushrooms.

A resistor limits electrical current. A memristor is a component whose resistance changes according to the voltage or current that has passed through it. In that limited sense, the component carries a trace of its recent electrical history.

When researchers sweep voltage in one direction and then back again, a memristive material can produce a pinched loop on a graph of current versus voltage. The shiitake-mycelium samples produced those hysteresis loops under several test conditions.

Engineers study memristors because memory and computation may be combined more closely than they are in a conventional computer. They are also of interest in neuromorphic systems, which borrow selected organizing ideas from nervous systems. Neither term means the material is conscious or learning like a person.

The team cultured shiitake mycelium in polycarbonate Petri dishes on a mixture of farro seed, wheat germ, and hay. The reported growing conditions were about 20–22°C (68–72°F) and 70 percent relative humidity with a mixed light cycle.

After the mycelium covered the growing medium, the samples were dried in direct sunlight at room temperature for about seven days. This produced rigid disks. Before electrical testing, the researchers lightly misted them with deionized water to restore conductivity without soaking them.

Nine cultures were prepared, and the paper describes electrical evaluation of four successfully cultivated samples. Electrodes, an oscilloscope, a signal generator, an Arduino Uno, and other ordinary hardware completed the experiments. This was mycelium grown through a substrate—not a grocery-store shiitake cap with wires attached.

In one comparison, the closest match to an ideal memristive curve was reported as 95 percent at a 10-hertz, 1-volt sine wave. The researchers also used a more pronounced loop at 10 hertz and 5 volts while developing the memory circuit.

For individual read-and-write operations below 1 hertz, the circuit reached a reported 96 percent accuracy. In repeated volatile-memory tests, reported accuracy was 91 percent at 200 hertz, 90 percent at 700 hertz, 88 percent at 1,125 hertz, 90 percent at 2,700 hertz, and 90 percent—plus or minus 1 percent—at 5,850 hertz.

The samples were also dehydrated and later rehydrated for testing. The authors reported that a previously programmed sample retained the observed properties through that process, suggesting that storage in a dry state may be worth investigating further.

A test frequency of 5.85 kilohertz is not equivalent to the clock speed of a processor. The circuit was repeatedly switching and checking a particular electrical state; it was not executing thousands of useful software instructions each second.

The reported accuracy was based on the experimental definitions used to judge curve matching or whether measured voltages crossed chosen read-and-write thresholds. It was not accuracy on a computing task, an artificial-intelligence benchmark, or ordinary file storage.

The paper did not demonstrate a practical storage capacity, dense bit array, operating system, general-purpose calculation, or head-to-head replacement for silicon memory. “Mushroom computer” is memorable shorthand, but it skips over most of what the experiment was designed to test.

Mycelium grows as a branching network and can respond electrically to changing conditions. If researchers can make that behavior consistent, biological materials could offer new ways to build specialized sensors, adaptive circuits, or low-cost experimental hardware.

The ability to dry a sample for storage and rehydrate it for testing is especially intriguing. A growable active material could eventually reduce some manufacturing steps or complement conventional components in applications where flexibility, unusual geometry, or lower material impact matters.

Those are possibilities, not outcomes established by this study. Environmental benefits would also have to be measured across cultivation, drying, supporting electronics, useful lifetime, and disposal. A biological ingredient does not automatically make the complete device sustainable.

• The study covered less than two months, so it did not establish a long operating life.
• Only a small number of relatively large, hand-grown samples were electrically evaluated.
• Biological cultures varied even when grown in the same medium, and the resulting electrical variability was not fully characterized.
• The samples were far larger than commercial electronic devices and were not organized into a dense integrated array.
• The effects of growth-medium composition, changing humidity, temperature, repeated cycling, and long-term storage need more systematic testing.

The authors acknowledge the early stage of the work and propose better cultivation control, standardized shapes, embedded contacts, preservation methods, and miniaturization. Those are not minor finishing steps; they are central challenges between an interesting laboratory result and a useful device.

First, independent teams would need to reproduce the electrical behavior across many more samples. Standardized strains, substrates, moisture levels, geometries, and electrode placement would help reveal which results belong to shiitake mycelium and which come from uncontrolled variation.

Next, researchers would need to measure endurance, retention time, energy use, switching speed, failure modes, temperature and humidity tolerance, and performance after repeated drying and rehydration. Miniaturized devices would have to work in arrays, not only as individual disks.

Finally, any sustainability claim would need a full comparison with existing components. Growing the active material is only one part of a device that still needs contacts, wiring, packaging, control electronics, and energy.

Yes: under laboratory conditions, dried and rehydrated shiitake mycelium acted as a memristive element and participated in a simple volatile-memory circuit.

No: the researchers did not build a practical mushroom computer or show that fungal material can replace modern memory chips. The result is a promising proof of concept whose value now depends on repeatability, miniaturization, durability, and honest comparison with existing technology.

That may sound less dramatic than the headline, but it is exactly what makes the work worth following: a familiar fungus displayed a useful electronic property in a carefully measured experiment, and the difficult engineering questions are now clearer.

The primary paper, “Sustainable memristors from shiitake mycelium for high-frequency bioelectronics,” was published in PLOS ONE on October 10, 2025. Two authors received support from Honda Research Institute; the paper states that the funder had no role in the study design, data collection and analysis, publication decision, or manuscript preparation. The authors declared no competing interests.

This summary uses the paper’s methods, results, discussion, and limitations rather than treating secondary headlines as evidence. The paper and its underlying data are openly available below.

• PLOS ONE paper: Sustainable memristors from shiitake mycelium for high-frequency bioelectronics
• PubMed Central: Full open-access paper
• Research data and analysis code on GitHub