From nature to organic (bio)electronics: a review on melanin-inspired materials

Melanin is a generic term evoked for a broad class of indole/quinone-based natural pigments, mainly known for its primary role in photoprotection. Throughout the last couple of decades, melanin and melanin-like materials garnered a lot of attention as a soft biocompatible functional material for bioelectronic and optoelectronic devices due to their water-dependent conductivity and excellent biocompatibility. However, in the earlier days, the limited solubility and low electronic conductivity have hindered their progression in such technological helms. Currently, these issues have been overcome by different strategies. This review briefly updates the physical-chemical properties of melanin and melanin-inspired materials, and their technological problems and applications. We also emphasize some chemical tailoring procedures for synthesis and processing. (AU)