According to their study, published in the paper Nano Journal, the team used button mushrooms due to their optimal levels of humidity and temperature which make them exceptional hosts to bacteria.
They then employed 3D printing technology to create a pattern of graphene nanoribbons on the cap of a living mushroom. They then printed cyanobacteria on top of the pattern using special ‘bio-ink’.This bacteria was selected due to its efficiency in converting sunlight to energy. According to researchers who participated in the study it has ‘an internal quantum efficiency of nearly 100%.’
Exposing mushroom to light triggers cyanobacterial photosynthesis during which the bacteria releases electrons that are in turn captured by the strips of graphene. According to a news release by the American Chemical Society, the team managed to generate 65 nanoamps of electric energy.