High‐Mobility Fungus‐Triggered Biodegradable Ultraflexible Organic Transistors

Biodegradable organic field‐effect transistors (OFETs) have drawn tremendous attention for potential applications such as green electronic skins, degradable flexible displays, and novel implantable devices. However, it remains a huge challenge to simultaneously achieve high mobility, stable operation and controllable biodegradation of OFETs, because most of the widely used biodegradable insulating materials contain large amounts of hydrophilic groups. Herein, it is firstly proposed fungal‐degradation ultraflexible OFETs based on the crosslinked dextran (C‐dextran) as dielectric layer. The crosslinking strategy effectively eliminates polar hydrophilic groups and improves water and solvent resistance of dextran dielectric layer. The device with spin‐coated 2,7‐dioctyl[1]benzothieno[3,2‐b][1]benzothiophene (C8‐BTBT) semiconductor and C‐dextran dielectric exhibits the highest mobility up to 7.72 cm(2) V(−1) s(−1), which is higher than all the reported degradable OFETs. Additionally, the device still maintains high performance regardless of in an environment humidity up to 80% or under the extreme bending radius of 0.0125 mm. After completion of their mission, the device can be controllably biodegraded by fungi without any adverse environmental effects, promoting the natural ecological cycles with the concepts of “From nature, for nature”. This work opens up a new avenue for realizing high‐performance biodegradable OFETs, and advances the process of the “green” electrical devices in practical applications.