Eumelanin as a Versatile Platform for Soft and Biointegrated Technologies

Eumelanin has evolved from a biologically intriguing pigment into a functional material of growing interest for sustainable and biointegrated electronics. What makes eumelanin stand out is its rare combination of properties, including water-dependent ionic-electronic charge transport, redox activity, biocompatibility, and susceptibility to degradation. These features make it a hydration-programmable material capable of offering distinctive value instead of being a replacement for high-conductivity electronics. By linking chemistry and supramolecular hierarchy to transport, processing, and mechanics for sensors, transistors, soft energy devices, and biointerfaces, this review seeks to show how eumelanin can guide more sustainable material choices while creating opportunities for innovation.