Recent research has unveiled that everyday materials can be engineered to function as memristors, components that retain memory of past electrical states. This innovative approach has potential applications in electronics, particularly in creating devices that perform computations and store data. Memristors typically consist of layers of titanium dioxide or similar materials, but scientists have discovered that organic substances like mushrooms, honey, and even blood can also serve this purpose.
Shiitake Mushrooms Show Promise
A team at The Ohio State University explored the electrical properties of fungi, leading to the surprising discovery that shiitake mushrooms can act as effective memristors. Lead researcher John LaRocco explained that these mushrooms demonstrate a unique ability to remember electrical states, similar to conventional memristors. The research involved cultivating nine shiitake samples under optimal conditions, feeding them a mixture of farro, wheat, and hay.
After maturing, the mushrooms were dried and rehydrated to achieve a moderate level of conductivity. This process creates conductive pathways, mimicking the oxygen vacancies crucial for traditional memristors. The results were promising; shiitake maintained ideal memristor-like behavior up to frequencies of 5.85 kilohertz, a notable achievement for biological materials.
LaRocco noted that shiitake mushrooms exhibit high resistance to radiation, making them particularly appealing for applications in aerospace and medical fields. He emphasized the environmental benefits, stating, “They’re already cultured in large quantities,” which could facilitate their commercialization.
Honey and Blood Offer Unique Alternatives
In a separate study, researchers at Washington State University examined whether honey could be used as a biodegradable alternative for memristors. Feng Zhao, who led the research, highlighted the urgent need for sustainable electronics, as modern devices generate approximately 50 million tons of e-waste annually. The team created a honey-based memristor by blending honey with water and removing air bubbles in a vacuum before applying copper electrodes.
The resulting device exhibited a switching speed comparable to some non-food-based memristive materials, capable of transitioning from low to high resistance in 500 nanoseconds. Zhao pointed out that honey’s low cost and widespread availability make it an attractive candidate for scalable production; however, for true biodegradability, future designs must replace copper components with dissolvable metals.
In an earlier study conducted in 2011, researchers in India investigated the potential of human blood as a memristor. They created a simple circuit using fresh type O+ blood, measuring current and resistance while applying different voltages. Their findings suggested that blood could exhibit memristor-like properties, as resistance changed minimally (less than 10 percent) over a thirty-minute period.
These explorations into unconventional materials highlight the potential of everyday substances to revolutionize electronic components. As research progresses, these organic alternatives could pave the way for more sustainable and versatile technologies.