The natural pigment, melanin, which endows humans and animals eye, skin and hair colour is set to be the driving force behind a new generation of bio-powered gadgets.

A research team from the University of Queensland led by Professor Paul Meredith and Associate Professor Ben Powell and incorporating an international team of scientists has published a study on the electrical properties of melanin and its biologically compatible “bioelectronic” features.

That biological compatibility means the first applications for melanin-based electronics would be on products for human implants.

Professor Meredith describes the pigment as like an organic semiconductor, composed of molecules containing carbon, hydrogen and other elements.

“There are very few examples of natural organic semiconductors and melanin was thought to be the very first example, demonstrated to be such in the early 70s,” said Professor Meredith.

The study, which has been evolving for ten years, reveals that in semiconductors, such as those found in computers and mobile phones, electrons carry the electrical current. However, in biological systems, such as brains and muscles, ions carry the current. While in melanin, both electrons and ions play important roles.

“Melanin is able to talk to both electronic and ionic control circuitry and hence can provide that connection role,” said Professor Meredith. The research is engaging in new ways of interfacing conventional electronics to biological systems using a combination of ion-and-electron conducting biomaterials such as melanin.

The team is currently working on creating ion-based electrical devices using melanin, with a view to ultimately connect them to actual biological systems. Applications could include stimulating or repairing signal-carrying pathways in tissues such as muscle or brain. Professor Meredith said that using the biomaterials would also solve the need for cheaper, safer electronic materials with greener credentials. ®

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