Every smartphone, every computer, and even many toys contain printed circuit boards. These boards hold the electronic components that make the device work. These very boards are usually made of a glass-fiber-reinforced plastic that is difficult to recycle.
A team at TU Bergakademie Freiberg has now developed a compostable alternative. The raw material for this is a byproduct of citric acid production.
A circuit board made from fungal residue
The production of citric acid leaves behind a network of fine fungal threads. Experts call this fungal mycelium. It comes from the mold Aspergillus niger and has mostly been discarded until now.
The Freiberg researchers use it to form a plastic-like material. They shape the fungal mass and air-dry it. This creates a board with a density similar to that of conventional printed circuit boards. The team then attaches electronic components directly to the new material.
According to Nina Oehlsen, a doctoral student at TU Freiberg and the study’s lead author, the material proved to be stable and heat-resistant in laboratory tests. It is already suitable for initial prototypes and simple electronic applications such as environmental sensors, toys, or everyday products. However, before it can replace conventional printed circuit boards, the material must undergo further testing and be improved so that it absorbs less water.
