Scientists have developed a cybernetic coating that could make it easier to interface hardware and human tissue.
Integrating electronics in the body could provide medical benefits, such as a device that monitors for tumours. They can also be used for implanted brain-machine interfaces that allow disabled people to control prosthetic limbs using their minds. Elon Musk’s Neuralink wants to take this further and achieve “symbiosis with artificial intelligence”.
Electronic signals need to be able to flow through a device for it to work. However, traditional microelectronic materials, such as silicon, gold and stainless steel cause tissue scarring when implanted and this disrupts electrical activity.
A team of scientists, who presented their research at the American Chemical Society Fall 2020 Virtual Meeting & Expo, investigated materials that could work as a cybernetic coating to prevent scarring.
“We got the idea for this project because we were trying to interface rigid, inorganic microelectrodes with the brain, but brains are made out of organic, salty, live materials,” said David Martin of the University of Delaware, who led the study. “It wasn’t working well, so we thought there must be a better way.
“We started looking at organic electronic materials like conjugated polymers that were being used in non-biological devices. We found a chemically stable example that was sold commercially as an antistatic coating for electronic displays.”
These polymers are both electrically active and ionically active. “Counter ions give them the charge they need so when they are in operation, both electrons and ions are moving around,” explained Martin.
The polymer is known as poly(3,4-ethylenedioxythiophene), or PEDOT. According to the research team, PEDOT increased signal quality and battery lifetime for implanted devices.
Cybernetic use cases
Martin and his team have also been tweaking the polymer for specific use cases.
“Name your favourite biomolecule, and you can in principle make a PEDOT film that has whatever biofunctional group you might be interested in,” he said.
In one example, the researchers created a PEDOT film that could detect tumours and so give an early warning of disease. They attached an antibody for vascular endothelial growth factor (VEGF), a protein that tumours hijack to increase their blood supply, to the PEDOT film.
This allows it to act as a sensor for when there is too much VGEF is present, which would indicate a tumour is growing.
The researchers have also carried out experiments on the polymers with neurotransmitters on them, which could help detect or treat brain disorders. Martin added that these biological-synthetic hybrid materials could one day be used for merging artificial intelligence with the human brain.