Fungal skin replaces plastics in electronics

In a proof-of-concept study, Doris Danninger and colleagues demonstrate that fungal mycelium skins can be grown and processed to serve as substrates for flexible electronics (Science Adv. doi: 0.1126/sciadv.add7118). The skins were used in batteries that powered autonomous humidity and proximity sensors outfitted with Bluetooth communication.

The researchers say that combining conventional electronics with this biodegradable substrate, in devices they call MycelioTronics, could help eliminate electronic waste and offer a new platform for conformable and wearable electronics, among other uses.

The skins are created using the saprophytic fungus Ganoderma lucidum, which grows naturally on dead hardwood. The electronic circuits are deposited on the skin using physical vapor deposition of thin metal that is then ablated by laser. The resulting electronic circuit has high thermal stability and can withstand thousands of bending cycles. Danninger et al. also found that the porous fungal skin can also soak up significant amounts of liquid, making it a promising candidate for sustainable battery separators. The skins allow common electronic processing techniques including physical vapor deposition and laser patterning for electronic traces with conductivities as high as 9.75 ± 1.44 × 10⁴ S cm^?1. The conformal and flexible electronic mycelium skins withstand more than 2000 bending cycles and can be folded several times with only moderate resistance increase. The researchers demonstrated mycelium batteries with capacities as high as ~3.8 mAh cm^?2 used to power autonomous sensing devices including a Bluetooth module and humidity and proximity sensor