Out of control: An epileptic seizure in a cat, as measured by the new electrode-dense implant, shows a never-before-seen spiral wave of electrical activity.

“This is absolutely terrific. I was astounded by the technical accomplishment, and the very strong and important results,” says Gerwin Schalk, a brain-computer interface researcher at the Wadsworth Center in Albany, New York. Schalk was not involved in the research. “It will be of tremendous value for basic neuroscience and for translational research.” Schalk notes that if the technology proves itself in humans, it could open up substantial opportunities for everything from diagnostics to brain-computer interface devices.

The device could also enable less-invasive testing and treatment. Rather than cutting open a large section of skull to place a monitoring device, Litt says, the new implant could allow surgeons to drill just a small hole through which to slip the slim, rolled-up sensor array, and unfurl it onto the brain’s surface once it’s inside. And instead of removing areas of brain the size of a golf ball, it might be possible to just remove the microdomains and leave the rest of the cortex intact.

The current version of the device is one square centimeter; for human use, researchers need to expand it to about eight square centimeters. A startup called MC10 will work on making it larger and production-ready.

Litt and Rogers are now working to create an implant with stimulators embedded next to the sensors. If they can build a device that not only detects the onset of a seizure but can just as quickly provide electrical stimulation to quash it, the research could have great clinical impact. “This isn’t just a research tool. It has a clearly defined mode of use in the clinical setting,” Rogers says. “This is a piece of biointegrated electronics that is unmatched in its functionality, and the proof is in the pudding.”