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Mushroom-based Substrates: Next Biodegradable Electronic Solution?

5 days ago by Jake Hertz

Hoping to pave a path toward more sustainable electronics, could research into mushroom-based substrates from Johannes Kepler University (JKU) of Linz be the answer?

The cleantech industry has seen a significant boom in the past decade from the proliferation of electric vehicles, but even this may not be enough. Alongside the need to cut down on fossil fuels, there is a significant need to reduce electronic waste, which is a major contributor to overall pollution.

One attempt to do this is by using biodegradable materials in electronics manufacturing. This week, researchers from the Johannes Kepler University (JKU) of Linz published a research paper describing a new means for biodegradable electronic substrates deriving from mushrooms.

 

Image showing the researcher's device next to mushrooms. Image used courtesy of JKU

 

In this article, we’ll discuss sustainability in electronics and the new research from JKU.

 

Sustainability for Electronics—The Need for Biodegradability

One of the biggest sustainability challenges in the electronics industry is how to deal with electronic waste.

From a socioeconomic perspective, one of the major reasons that we produce so much electronic waste is due to the dynamism of the technology industry. As defined by Moore’s Law, technology gets significantly better year after year. The result is that technology becomes quickly antiquated and, eventually, thrown out. 

 

The global trend for e-waste shows a steady increase.

The global trend for e-waste shows a steady increase. Image used courtesy of Statista

 

From an environmental perspective, the reason that this is so alarming is that electronics are largely non-biodegradable. Even worse, many of the electronic components found on a typical PCB, and even the PCB itself, tend to be toxic. This issue means that electronics not only pile up and can’t be cleanly eliminated, but they also actively damage the earth through leakages.

To address this, many researchers are looking for biodegradable and/or environmentally benign materials from which engineers can manufacture future electronics.

 

JKU Leverage Mycelium Skin for Biodegradable Electronics

This week, researchers from JKU published a new research paper describing a potential path forward for sustainable electronics.

Specifically, the researchers investigated the feasibility of using the mycelium skin of a mushroom, the outer layer which protects the fungus from pathogens, as a means of electronic conductivity. To do this, the researchers created a lab setup in which they grew their mycelium skin that was then dried and used as an electrical conductor.

 

The concept for a mycelium battery. I

The concept for a mycelium battery. Image used courtesy of Danninger et al

 

In their research paper, the team describes that the skins should be compatible with common electronic processing techniques and allow for the creation of traces with conductivities as high as 9.75 ± 1.44 × 104 S cm−1. Further, the mycelium skins could withstand more than 2000 bending cycles, showing good future promise for their application in stretchable electronics and wearables.

As a proof of concept, the researcher then demonstrated mycelium batteries by soaking the mycelium skin in a liquid electrolyte and sandwiching it between current collectors. The resulting battery exhibited capacities as high as 3.8 mAh cm−2 and discharge current up to 2 mA. This was then used to power a sensing device that consisted of a humidity sensor, proximity sensor, and a Bluetooth module.

Most importantly, being a natural material, the mycelium skin batteries were biodegradable. With this research, the team hopes to open doors for a future where biodegradable electronics can eliminate the electronic waste epidemic.