Silk May be Future Material for Brain/Computer Interface

Silk is being used to make electronics that stick to the brain. A far cry from fabric but doctors are hoping that using silk will help them explore parts of the brain that they weren’t previously able to.

“This development heralds a new class of implantable devices, not just for the brain, but for many other tissues,” said neurologist Brian Litt of the University of Pennsylvania, in an interview with Wired.com.

Engineers chose to use silk because it’s easily stretched and the material is super thin, making it easy to mould and work with, making for better brain-computer interfaces. BCI’s monitor and record brain activity of patients who have been paralyzed. Engineers hope to use those results along with robotic arms or cursors as a way to convert thoughts into actions and move for those who can’t.

“This will significantly improve recording by conforming the electrode array to the surface of the brain,” said biomedical engineer Barclay Morrison of Columbia University. “It will move forward the field of flexible electronics.”

Engineers used silk films, a mere 2.5 microns thick, which disintegrate when exposed to a saline solution. Once the film dissolves away, the electrode arrays are left to conform themselves to the brain.

After testing, the team of engineers found that the silk attached itself to a model of the brain perfectly. They tested on the visual processing area of a cat’s brain and found no harm or inflammation after being placed there for a month. The silk-based electronics seem to produce better signals and results than a thicker and more stiff electrode array would have.

“Its full potential remains to be seen in long-term BCI studies,” Morrison said. “Currently, there are no BCIs that use such compliant mesh electrodes, and the potential is pretty big that the implant array will provide a neural interface that is stable over a long period of time.”

Scientists are highly optimistic about this new way of recording brain activity without harm, unlike silicone, which can pierce and harm tissues while being implanted. The hope is to be able to adjust the technology and use it for patients with retinal and cochlear implants as well as to treat those with many different psychiatric diseases.