Natural melanins such as squid ink are being considered as new materials for bioelectronics. Image: Paul Schwenn
pigment that colors 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.
are arguably the most important modern day high-tech material—they drive all
modern electronics,” said Meredith.
“The majority of
semiconductors are made from inorganic elements or compounds such as silicon or
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
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.
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 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.”
In recent years,
the electronics industry has been driven to develop materials and components
that are cheaper and more environmentally friendly.
“There is a realization
that in many such applications, we should move on from the relatively more
expensive inorganic semiconductors. We need cheaper, safer electronic materials
with greener credentials,” said Meredith.
conductors and semiconductors are widely viewed has having enormous potential
in this regard, and in the area of medical sensors and devices, biocompatibility
will be a key requirement.”
The team is
currently working on creating ion-based electrical devices using melanin, with
a view to ultimately connect them to actual biological systems.
“A critical area
that one could foresee for bioelectronics is stimulating or repairing
signal-carrying pathways in tissues such as muscle or brain,” said Meredith.
Source: The University of Queensland