DARPA-backed researchers create dissolvable electrodes for brain monitoring

Scientists at the University of Pennsylvania in a study funded by the Defense Advance Research Projects Agency (DARPA) are developing implantable electrodes for brain monitoring that melt away at a predetermined rate. The devices could come in handy for monitoring and treating certain neurophysiological disorders such as Parkinson's, depression and chronic pain.

The electrodes, which are made from layers of silicon and a chemical element, molybdenum, dissolve at a known rate according to thickness. The devices can provide "continuous streams of data for guiding medical care over predetermined periods of time," Brian Litt, senior co-author on the study and a professor of neurology, neurosurgery and bioengineering at UPenn, said in a statement.

The dissolvable electrodes also "eliminate the risks, cost, and discomfort associated with surgery to extract current devices used for post-operative monitoring," Litt said. Scientists recently published their findings online in Nature Materials.

To test the system, researchers used the electrodes to record brain waves in rats who were under anesthesia. The scientists also tested the device on intact live tissue samples with induced epileptic spikes.

A separate experiment showed that the electrodes could also map rat-whisker sensing capabilities at high resolution. The signals were recorded from devices placed at the surface of the outer layer of tissue in the brain and the inner space between the scalp and skull, the researchers said.

Researchers envision multiple applications for the technology. In addition to screening for certain neurological conditions, the devices could be used to monitor for seizures that occur after surgery and to check brain function after an operation, Litt said.

"Recent evidence suggests that up to three months of intracranial recording may be required to adequately locate seizures before epilepsy surgery or device placement. This is a period of time that is prohibitively long for existing in-hospital approaches," Litt said. "Using our dissolvable electrodes for this situation would eliminate the danger and cost of removing electrodes."

Next up, the team will develop complex devices that include flow and pressure monitors in addition to electrical recording. Researchers will test the system on animals first but plan to move the electrodes into human testing, the scientists said.

- here's the release