There are a number of conditions where monitoring the brain and its functions are very important. For example, monitoring the brain of an epileptic patient allows doctors and electronic equipment see the beginning of a seizure and administer electric shocks to stop the seizure from happening.

The problem with this type of monitoring with technology today is that it requires the insertion of thin wires into the brain of a patient and the silicon circuits used to capture the signals sent from the electrodes are not flexible and won’t conform to the brain's surface.

However, a group of researchers at the National Institutes of Neurological Disorders and Stroke (NINDS) has developed a new type of brain implant that melts to the brain conforming to its surface. The scientists believes that the technology could pave the road for devices that better control, monitor seizures, and transmit signals from the brain past damaged areas of the spinal cord. The study findings from the team were published in a recent issue of Nature Materials.

Dr. Walter Koroshetz said, "These implants have the potential to maximize the contact between electrodes and brain tissue, while minimizing damage to the brain. They could provide a platform for a range of devices with applications in epilepsy, spinal cord injuries, and other neurological disorders."

The implants that the team developed hold metal electrodes that are about 500 microns thick. The device has no sharp surfaces or edges and uses a material based on silk. The conforming design of the implant and the lack of sharp edges means less damage to the brain tissue and improved reception of brain signals.

Dr. Brian Lott, a study author, said, "The focus of our study was to make ultrathin arrays that conform to the complex shape of the brain, and limit the amount of tissue damage and inflammation."

The flexible electrodes in the implant also means that the implant can be stretched out to cover larger sections of the brain allowing the capture of signals from a larger section of the brain. Silk was chosen as the base for the implant because it is flexible and durable enough to survive the process that patterns the thin metal traces for electrodes on its surface.

Silk was also chosen because the material can be engineered to avoid inflammatory reactions and to dissolve at specific points be it immediately on contact with the brain or years down the road. The team used electrodes that can be printed on layers of polyamide and silk that are positioned on the brain. The implant then melts and conforms to the curved and creases of the brain providing contact for measurement of signals.

The silk-based test implants were designed and developed by the University of Illinois in Urbana-Champaign and Tufts University. The implants have been tested in anesthetized animals so far to determine the ideal thickness for the implants. The test arrays had 30 electrodes in a 5x6 pattern on a thin layer of polyimide with and without silk base. The silk base implants were found to work the best and were able to capture stronger signals that thicker implants. The team also believes that the implants may be able to be compressed and delivered through a catheter into the brain.