Sensor wraps itself round the brain
Scientists have developed a brain implant that melts into place, fitting to the brain's surface like shrink-wrap.
The ultrathin flexible implants, made partly from silk, can record brain activity more accurately than thicker implants embedded with similar electronics, say the researchers.
The arrays could be used to detect when epileptic seizures first begin, and deliver pulses to shut the seizures down. In people with spinal cord injuries, the technology has promise for reading complex signals in the brain that direct movement, and routing those signals to healthy muscles or prosthetic devices.
"These implants have the potential to maximize the contact between electrodes and brain tissue, while minimizing damage to the brain," says Walter Koroshetz, deputy director of the National Institute of Neurological Disorders and Stroke (NINDS).
"They could provide a platform for a range of devices with applications in epilepsy, spinal cord injuries and other neurological disorders."
The implants contain metal electrodes that are just 500 microns thick. The absence of sharp electrodes and rigid surfaces should improve safety, with less damage to brain tissue.
Also, the implants' ability to mold to the brain's surface could provide better stability; the brain sometimes shifts in the skull and the implant could move with it. Finally, by spreading across the brain, the implants have the potential to capture the activity of large networks of brain cells.
In the future, the researchers hope to design implants that are more densely packed with electrodes to achieve higher resolution recordings.
"It may also be possible to compress the silk-based implants and deliver them to the brain, through a catheter, in forms that are instrumented with a range of high performance, active electronic components," said John Rogers, a professor of materials science and engineering at the University of Illinois.