JKU researchers recently began using glossy paint fungus skin (Ganoderma lucidum) as a substrate for electronic components.
Scientists have dubbed the new innovative substance "MycelioTronics" and Martin Kaltenbrunner (Department of Soft Matter Physics at the JKU) believes it’s a "global first" that could result in more sustainable electronics. At any rate, the fungal skin is an “ingenious barrier”.
As described in the journal "Science Advances" under the leadership of the study's first authors Doris Danninger and Roland Pruckner, the approach was "more or less an accidental discovery", "… as is so often the case when it comes to science," remarked Kaltenbrunner. He added that the institute has focused on the topic of "fungi" for some time now but more in other contexts, such as insulation in the construction industry and using mycelium materials as an alternative to Styrofoam.
As part of a new study, the team (which has made waves in recent years thanks to many new developments in robotics and electronics) also looked at applying fungi to support sustainable electronics. Kaltenbrunner explained that scientists discovered that in order to protect itself from pathogens and other fungi, glossy paint fungus forms a closed mycelium skin on the surface of its growing medium. It turns out that this skin can be easily removed then processed further.
Scientists can even use the skin directly for a project; it just needs to be dried. The skin could be used, for example. as a flexible printed circuit board "… to manufacture electronics atop of it". Kaltenbrunner added, “…producing the pulp, however, is energy-intensive and not really sustainable. The mushroom skins only need waste wood to grow."
The material's robust, flexible, and heat resistant properties could potentially become a polymer substitute for polymers currently used in making flexible electronic components. Kaltenbrunner explained that all types of printed circuit boards are made out of composite materials that are generally difficult to separate, recycle, or decompose. This biodegradable mushroom skin, however, is now emerging as a true alternative.
As an initial step, Linz researchers envision physical applications, such as in the field of medical technology, where these kinds of components need to primarily work for periods of up to a year. "We have created proximity and humidity sensors, for example, and they also work well." The scientist made them by soldering "relatively conventional electronic chips" onto the mycelium substrate. Incidentally, he added, the fungal skin is also surprisingly heat-resistant, able to withstand temperatures of up to 250°C. This is an important factor when building circuits.
When it comes to developing new types of batteries that consist mainly of mycelium, this material is interesting as it can wirelessly power electronics. Scientists have already begun to pursue initial approaches and are now trying to adapt the membrane properties formed by fungal skin to various applied ideas. One key would be to make the naturally grown structure even more homogeneous and ultimately place the electronics on top of it; they would be just as biodegradable as the carrier material. Kaltenbrunner added: "That would then be the next step and for that, the surface would have to be even smoother."
Translation: N. Lichtenberger