High conductivity Sepia melanin ink films for environmentally benign printed electronics

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 119; no. 32; p. e2200058119
• Main Authors: Camus, Anthony, Reali, Manuel, Rozel, Michael, Zhuldybina, Mariia, Soavi, Francesca, Santato, Clara
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 09.08.2022
• Subjects: Animals; Broadband; Conductivity; Electronics; Electronics - instrumentation; Feature extraction; Flora; Humans; Ink; Invertebrates; Melanin; Melanins - chemistry; Optical properties; Organic materials; Physical Sciences; Pigmentation; Pigments; Polymers; Scavenging; Sepia; Sepia - chemistry; Toxicity; Vertebrates; electronic conductivity; percolation; bio-sourced materials; ink formulation; flexographic printing
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2200058119

Melanins (from the Greek μέλας, mélas, black) are bio-pigments ubiquitous in flora and fauna. Eumelanin is an insoluble brown-black type of melanin, found in vertebrates and invertebrates alike, among which Sepia (cuttlefish) is noteworthy. Sepia melanin is a type of bio-sourced eumelanin that can readily be extracted from the ink sac of cuttlefish. Eumelanin features broadband optical absorption, metal-binding affinity and antioxidative and radical-scavenging properties. It is a prototype of benign material for sustainable organic electronics technologies. Here, we report on an electronic conductivity as high as 10 S cm in flexographically printed Sepia melanin films; such values for the conductivity are typical for well-established high-performance organic electronic polymers but quite uncommon for bio-sourced organic materials. Our studies show the potential of bio-sourced materials for emerging electronic technologies with low human- and eco-toxicity.