Ultimately, Xenophon Strakosus, an assistant professor working in Berggren’s lab, pinpointed the problem. In plants, hydrogen peroxide helps the infused materials bind together, but in animals there isn’t enough peroxide for the reaction to work, so Strakosas added some additional elements to the mix. Added to An enzyme that uses glucose or lactic acid, common in animal tissues, to generate peroxide, and another that breaks down peroxide. Suddenly the electrode was fully formed.
For experts like Maria Asplund, professor of bioelectronics microtechnology at Chalmers University of Technology in Sweden, the idea of forging electrodes inside the body is completely new. “Chemists can do things I never imagined,” she says. But her Asplund, who has spent more than a decade creating more brain-friendly electrodes, isn’t going to abandon her tried-and-true method for making electrodes just yet. First, this new tool has not been tested in mammals, and no one knows how long it will last in the body. and his colleagues don’t have a solution for getting those signals out of the brain so that scientists can actually see them, or for sending electrical currents like electrodes can. used for stimulation.
They have many options. One is to stick an insulated wire directly into the electrode to carry that signal from deep inside the brain to the surface of the skull, allowing scientists to measure them. Instead, they designed other components, like electrodes, that could self-assemble in the brain so that the signal could be read wirelessly from the outside. There is likely to be.
Even if Berggren and his colleagues found a way to communicate with the electrodes, they would still struggle to compete with cutting-edge devices like the following. neuropixel, can be recorded from hundreds of neurons at once. Achieving that degree of accuracy with soft electrodes may prove difficult, says Jacob Robinson, an associate professor of electrical and computer engineering at Rice University in Texas. “Usually there is a trade-off between performance and invasiveness,” he says. “The engineering challenge is to push the boundaries.”
Stimulation to the brain, at least initially, may be a better application for soft electrodes, as it does not need to be as precise. And even an inaccurate record could benefit a completely paralyzed person, says Aaron Batista, a bioengineering professor at the University of Pittsburgh who studies monkey brain-computer interfaces. say. Soft electrodes may not be able to produce fluent speech by directly measuring someone’s brain signals, but for patients who cannot move at all, they can simply say “yes” or “no.” , makes a big difference.
But polymer electrodes aren’t just a safer, more cumbersome version of traditional electrodes. Because they only form in the presence of certain substances, they can be used to target parts of the brain with specific chemical profiles. So I plan to tweak the recipe so that the gel only solidifies in highly active areas. That strategy could be used to specifically target areas of the brain where someone’s seizures start. In principle, it is also possible to create materials that use other substances to help form electrodes, such as specific neurotransmitters, rather than glucose or lactate. That way, the electrodes would only reach those parts of the brain that are high in that particular neurotransmitter, allowing neuroscientists to precisely target specific brain regions.
Even if Berggren and his team manage to overcome the scientific obstacles in front of them, their final task is navigating the regulatory thickets that govern the equipment used in medical practice. For a material so novel it’s impossible to predict how long it will take. But Batista believes the discovery will usher in a new era in electrode technology.
“I don’t know if anyone alive today will have a flexible electronic neural implant,” he says. “But it seems likely that someday someone will.”
