A new high- resolution, ultra-thin device that can record brain activity from the cortical surface without the use of invasive electrodes has been developed by a team of researchers from the University of Pennsylvania.

Tapping into the brain without the use of penetrating electrodes and sensors that only provide a narrow view into the brain has long been a goal of researchers.

Now a team of researchers co-led by Jonathan Viventi has devices a new brain interface that can help doctors and scientists learn more about the brain and brain diseases as well as usher in more improvements in implantable neuroprosthetic devices.

The new device is composed of 720 silicon nanomembrane transistors that integrate ultrathin, flexible silicon transistors that can be positioned on the brain surface and in areas that are physically inaccessible to conventional rigid electrode arrays. The multiplexed sensors can cover a much larger brain area with better resolution than traditional wire electrodes.

Current efforts to monitor brain activity are limited by the need to wire each sensor at the electrode-tissue interface. These devices are clumsy to use and only offer low resolution images. Some neuromotor prostheses can even cause inflammation and hemorrhages. The new device can offer more the 400 times the resolution of current electrode devices and only uses a fraction of the wires. The arrays also cause little or no damage to the brain tissue.

"The new technology we have created can conform to the brain's unique geometry, and records and maps activity at resolutions that have not been possible before," says Brian Litt, MD, the study's senior author and Associate Professor of Neurology at the Perelman School of Medicine and Bioengineering at the University of Pennsylvania.

"Using this device, we can explore the brain networks underlying normal function and disease with much more precision, and its likely to change our understanding of memory, vision, hearing and many other normal functions and diseases."

The research team had been successful in using the new system to monitor the brain activity of animals. They have also recorded and observed the brain of a sheep during an epileptic seizure.

"Someday, these flexible arrays could be used to pinpoint where seizures start in the brain and perhaps to shut them down," said Brian Litt, M.D., the principal investigator and an associate professor of neurology at the University of Pennsylvania School of Medicine in Philadelphia.

The new array could also be used in other implantable devices such as cardiac pacemakers and defibrillators, cochlear and retinal implants and motor prosthetic systems. The researchers also hope to someday develop these flexible sensors to use anywhere in the body and equipped with wireless sensors that can record and stimulate parts of the body. The team's findings were published in Nature Neuroscience.