In a nutshell: While you consider gold, pictures of knickknack or bullion in all probability come to thoughts. However a group from Linköping College in Sweden has used the metallic to create electrodes for interfacing with the human nervous system as a substitute – and in an entire new approach. They’ve designed gold nanowires which might be comfortable and stretchy sufficient to be really biocompatible and related to the nervous system.
Their work, revealed within the journal Small, may pave the best way for brand new varieties of medical implants and interfaces that stand up shut and private with our nerves with out damaging them. These electronics may assist deal with circumstances like epilepsy, Parkinson’s, paralysis, or continual ache by seamlessly integrating with the physique.
“The classical conductors utilized in electronics are metals, that are very onerous and inflexible. The mechanical properties of the nervous system are extra harking back to comfortable jelly,” explains supplies science professor Klas Tybrandt, who led the analysis. “To get an correct sign transmission, we have to get very near the nerve fibers in query.”
Nevertheless, because the physique is consistently in movement, reaching shut contact between onerous and comfortable supplies is an issue. Utilizing comfortable, stretchy electrodes solves this since they do not trigger as a lot tissue harm as stiff metallic ones. However making them conductive sufficient whereas additionally being biocompatible has been a significant problem, which is the place the gold nanowires are available.
Tybrandt’s group embedded extremely skinny strands of gold – round 1,000 occasions slimmer than a human hair – in comfortable, versatile silicone rubber to create their electrodes. Silicone is already used for implants like breast implants, and gold and platinum are widespread in medical units too.
However fabricating lengthy, slender nanostructures from gold has been troublesome – till now. The researchers discovered a intelligent workaround beginning with skinny silver nanowires, that are a lot simpler to make due to silver’s distinctive properties.
Laura Seufert, a doctoral scholar in Klas Tybrandt’s analysis group, determined to make use of silver nanowire as a template to develop gold round it. The silver is then eliminated, forsaking a construction that is over 99% pure gold.
The method is hard, however price it for the creation of electrodes that mix excessive electrical conductivity with the softness and biocompatibility wanted to interface with the physique long-term. Assessments confirmed the fabric ought to stay steady for not less than three years after implantation.
To reveal their comfortable gold electrodes, the researchers labored with Linköping neurologist Simon Farnebo to efficiently stimulate and report alerts from rat nerves.
With the fundamentals out of the best way, the group is now trying to refine the fabric additional to create even smaller electrodes that may get nearer to particular person nerve cells. From pacemakers to brain-computer interfaces, the way forward for bioelectronics could have a golden lining – or not less than, golden nanowires pulling the strings behind the scenes.
