Ilaria Rosella Pagliaro A Swiss team has developed mushroom batteries, combining 3D technology and microorganisms: these biodegradable batteries represent an ecological solution for energy in isolated regions
©Empa
Swiss researchers have taken a leap further in renewable energy by powering biodegradable batteries with fungi. Thanks to research at Empa, the Swiss Federal Laboratories for Materials Science and Technology, this innovative technology might be revolutionary regarding energy solutions for devices operating in very remote areas. But exactly how would the fungi-based batteries work?
How do fungi-powered batteries function?
The batteries developed by Empa scientists are a variety of microbial fuel cell, wherein microorganisms convert nutrients into energy and, in the process, generate electricity. This is the first time two types of fungi have been used together to produce a functioning battery, says Carolina Reyes, one of the researchers involved in the project.
It would be based on a two-electrode configuration. The negative-essentially anode-relies on the metabolism of yeast, which emits electrons in its respiration process. On the other side, at the cathode-end, there is a type of fungus, white rot fungus, which produces this unique enzyme that captures those electrons and channels them out of the cell. The fungi will be kept alive with some simple sugars which are put inside the battery cells.
One of the amazing things about these batteries, Reyes explains, is how easily they can be activated:
“They can be stored in a dried state and then activated on-site, merely by adding water and nutrients.”
Where do fungi-based batteries come from?
As innovative as these batteries are in their operation, their production process is unique. The fungi are not just “added” in the battery; rather, they are integrated right into the base material from the very start. This is through a 3D printing process.
The electrodes are designed to make nutrients more accessible for microorganisms with the use of a special ink. This ink is not only biocompatible but also biodegradable and is based on cellulose, which fungi can use as an additional nutrient. As Gustav Nyström, head of Empa’s Cellulose and Wood Materials Laboratory, says:
“The main challenge was finding a material that allowed the fungi to grow well, was easy to extrude, and, at the same time, conducted electricity.”
Thanks to the team’s expertise in 3D printing with bio-based materials, they were able to develop an ink that meets all these requirements. Moreover, at the end of the battery’s life cycle, the fungi themselves help degrade it from within, making it entirely eco-friendly.
Possible applications of fungi-powered batteries
Though generating a high amount of electricity is yet a long-run goal, a battery powered by fungi already has some practical applications. Currently, it is able to provide enough energy for small devices, like temperature sensors, to work for several days. That makes them perfect for application in agriculture or scientific research in remote areas where traditional energy solutions would be hard to implement.
Reyes and Nyström say,
Fungi represent an underrated and understudied kingdom of nature,
especially in material science.
Further studies are needed to improve the efficiency and durability of these batteries, while seeking more fungal species able to produce electricity.
Source: EMPA
