The arrays consisted of 30 electrodes in a 5x6 pattern on an ultrathin layer of polyimide with or without a silk base. These experiments led to the development of an array with a mesh base of polyimide and silk that dissolves once it makes contact with the brain so that the array ends up tightly hugging the brain.
Next, they tested the ability of these implants to record the animals' brain activity. By recording signals from the brain's visual center in response to visual stimulation, they found that the ultrathin polyimide-silk arrays captured more robust signals compared to thicker implants.
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," Dr. Rogers said.
|Contact: Daniel Stimson|
NIH/National Institute of Neurological Disorders and Stroke