Melanin considered for bio-friendly electronics
Date: 8.10.2012
Phys.org, June 27, 2012: Melanin – the pigment that colours skin, eyes and hair – could soon be the face of a new generation of biologically friendly electronic devices used in applications such as medical sensors and tissue stimulation treatments.
Led by Professor Paul Meredith and Associate Professor Ben Powell at The University of Queensland, an international team of scientists has published a study that for the first time gives remarkable insight into the electrical properties of this pigment and its biologically compatible “bioelectronic” features.
“Semiconductors are arguably the most important modern day high-tech material – they drive all modern electronics,” said Professor Meredith. “The majority of semiconductors are made from inorganic elements or compounds such as silicon or gallium arsenide.”
Organic semiconductors, on the other hand, are a relatively new member of the semiconductor family and are 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. Co-author Associate Professor Powell said 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. “We've now found that in melanin, both electrons and ions play important roles,” he said. The study – published recently in Proceedings of the National Academy of Sciences – points to a new way of interfacing conventional electronics to biological systems using a combination of ion-and-electron conducting biomaterials such as melanin.
“Melanin is able to ‘talk' to both electronic and ionic control circuitry and hence can provide that connection role,” said Professor Meredith about the study's finding, the culmination of ten years of research and experiments. “There are very few materials that meet these compatible bioelectronic requirements, and an insight into melanin's important biological functions and properties has been really crucial in this study.”
