Wooden computer mouse
Electronics on the compost heap. What sounds utopian has been pioneered by Empa researchers with their new, wood-based printed circuit board. As part of the HyPELignum project, they have created the first functional electronic products that are not only powerful but also fully compostable.
Bild: Empa
Printed circuit boards are the invisible backbone of electronics. Until now, they have mostly been based on fossil plastics. Their conventional production uses glass fiber-reinforced epoxy resin. A petroleum-based material that is almost impossible to recycle at the end of its life cycle and requires costly disposal. This recycling problem is becoming increasingly urgent in view of the growing quantities of electronic waste.
Empa’s “Cellulose and Wood Materials” laboratory has therefore developed a carrier material based on wood that can be completely biodegraded. Under the leadership of Thomas Geiger, the team in the EU project HyPELignum developed a technology in which lignocellulose – a previously underutilized by-product of wood processing – is transformed into a robust, functional board.
Closing the loop between function and cycle
At its core, the new material consists of a mixture of cellulose fibrils and lignin. Finely tuned mechanical processes create a stable mesh that hardens in a “hornified” board. The printed circuit boards made from this material can be printed with conductor tracks and fitted with electronic components.
Moisture resistance remains the key challenge. This is because it is precisely the material’s openness to water that makes it biodegradable at the end of its life. A conflict of objectives that the Empa team wants to resolve even better in future. In their first experiment, they have already succeeded in building a fully functional computer mouse and other devices. After use, these could be composted under suitable conditions and valuable metals and components simply recovered.
From research to practice
The developers at the Empa laboratory are working closely with companies such as Profactor to transform the new circuit boards into products ready for series production. The potential for industry is huge. Especially in the case of short-lived electronic items, this creates a solution that conserves resources, reduces disposal costs and minimizes the ecological footprint.
The HyPELignum project also emphasizes sustainable overall strategies. The focus is not only on raw materials and production, but also on life cycle analyses and industrial partnerships. With demonstration devices and planned industrial scaling, the aim is to make the leap from laboratory solution to market-ready product by 2026.