Graphene Ink From Recycled Sensors Survives Five Reprint Cycles With No Performance Loss

Researchers at Silicon Austria Labs and EPFL developed a graphene ink that can be recovered from used printed sensors and reused for at least five printing cycles without losing performance. The ink uses linalool, a plant-derived solvent, instead of petrochemicals like NMP and toluene. The team recovered more than 93% of the graphene along with the solvent and PET substrate, then printed new sensors and heaters with the reclaimed material. A materials-level carbon footprint assessment puts the fresh ink at 16.02 kg CO2 equivalent per kg, about 42% below conventional graphene inks, and recycled ink at 6.49 kg CO2 equivalent per kg. The assessment only covers material components, not the energy used in production, printing, or recycling. The work is published in Communications Sustainability and points to a more circular path for printed electronics.