Engineers from the University of Michigan at Ann Arbor have developed a new electrode coating that promises a better and longer quality connection to neurons in the brain. Because current brain/computer interfaces are becoming sophisticated enough to be useful, it is hoped that the new technology will make them surgically practical as well.
The coating is made of a special electrically-conductive nanoscale polymer called PEDOT; a natural, gel-like buffer called alginate hydrogel; and biodegradable nanofibers loaded with a controlled-release anti-inflammatory drug.
The PEDOT in the coating enables the electrodes to operate with less electrical resistance than current models, which means they can communicate more clearly with individual neurons.
The alginate hydrogel, partially derived from algae, gives the electrodes mechanical properties more similar to actual brain tissue than the current technology. That means coated neural electrodes would cause less tissue damage.
The biodegradable, drug-loaded nanofibers fight the “encapsulation” that occurs when the immune system tells the body to envelop foreign materials. Encapsulation is another reason these electrodes can stop functioning properly. The nanofibers fight this response well because they work with the alginate hydrogel to release the anti-inflammatory drugs in a controlled, sustained fashion as the nanofibers themselves break down.
“Penetrating microelectrodes provide a means to record from individual neurons, and in doing so, there is the potential to record extremely precise information about a movement or an intended movement. The open question in our field is what is the trade-off: How much invasiveness can be tolerated in exchange for more precision?” said Daryl Kipke, a professor in the Department of Biomedical Engineering and the director of the U-M Center for Neural Communication Technology.