A living battery made from fungi
Two species of fungi work together to generate energy – which can then be used to power agricultural sensors.
From single-celled organisms to the largest organisms on Earth, from disease-causing pests to 'superheroes' that produce life-saving medicines, fungi, which are closer to animals than plants, are true all-rounders. Now, researchers at the Cellulose and Wood Materials Laboratory of the Swiss Federal Laboratories for Materials Science and Technology (Empa) have coaxed another potential application out of fungi: they can also generate electricity.
A fuel cell made from fungi
This is made possible by combining two types of fungus in a so-called microbial fuel cell: the anode is formed by a yeast fungus whose metabolism releases electrons, while the cathode is colonised by a white rot fungus, the velvet tramete. The latter produces a special enzyme that can capture the electrons and carry them out of the cell. The result: small amounts of energy that can power sensors in agriculture, for example, for several days.
Fungi are true all-rounders. Empa researchers have been able to use them for energy generation.
Created using a 3D printing process
As the researchers explain, the fungi are not planted into the battery during its construction, but are an integral part of the cell from the outset. The components of the fungal battery are produced using 3D printing, which makes it possible to structure the electrodes so that the micro-organisms have easy access to nutrients – the fungal cells are mixed into the printing ink for this purpose.
For the first time, we have combined two types of fungi to create a functioning fuel cell.
Battery biodegrades after use
This is done because the battery does not need to be charged, but rather 'fed' in order to function. The researchers have produced an ink with cellulose-based nutrients that gives the fuel cell another positive property: when the battery is no longer needed, it can digest itself and thus biodegrade.
Next goal: increase performance and durability
The next step for the researchers is to improve the battery to make it more powerful and durable, and to look for other mushroom species that could be used to produce electricity. So far, they have mainly been used to power sensors in agriculture or environmental research in remote regions. But the foundations have been laid for more widespread applications in the future.
And who knows, maybe one day we'll even be riding around on e-bikes powered by fungal energy!