Brains have the texture of Jell-O—push on them too hard, and they’ll come apart into fragile clumps. There’s a violence to probing the brain with wires. “It’s like sticking a knife into the tissue,” says Magnus Berggren, professor of organic electronics at Linköping University in Sweden.
Scientists have recognized the extensive damage that electrodes can cause since at least the 1950s. Generations of engineers have labored to solve the problem by crafting ever-smaller and ever-more-flexible devices, but these have their own shortcomings. There’s no good way to get a flexible electrode deep into the brain, and even when placed at the brain’s surface, such electrodes may not function well over long time periods.
But Berggren and his colleagues think they may have developed a solution. Rather than making an electrode outside of the brain and then trying to implant it, they have designed a gel that, when injected into bodily tissue, solidifies into an electrically conductive polymer. The process isn’t unlike pouring molten metal into a mold, except that the gel is apparently harmless, and the electrode, once it forms, is just as soft and movable as the brain tissue around it.
The team published their results in February in the journal Science.
