Researchers develop graphene-biosensors for brain machine interfaces

Researchers at the University of Technology Sydney (UTS) have developed a novel graphene-based biosensor, set to drive new innovations in brain-controlled robotics.

The biosensor adheres to the skin of the face and head in order to detect electrical signals being sent by the brain. These signals can be translated into commands to control autonomous robotic systems. The sensor, made of epitaxial graphene grown onto a silicon carbide on silicon substrate, overcomes the major challenges of corrosion, durability and skin-contact resistance.

"We've been able to combine the best of graphene, which is very biocompatible, very conductive, with the best of silicon technology, which makes our biosensor very resilient and robust to use," says UTS Professor Francesca Iacopi.

Graphene is used frequently in the development of biosensors. However, the team explains that to date, many of these products have been developed as single-use applications and are prone to delamination as a result of coming into contact with sweat and other forms of moisture on the skin.

By contrast, the UTS biosensor can be used for prolonged periods and re-used multiple times, even in highly saline environments. Furthermore, the sensor has been shown to dramatically reduce what's known as skin contact resistance, where non-optimal contact between the sensor and skin impedes the detection of electrical signals from the brain.

"With our sensor, the contact resistance improves when the sensor sits on the skin," Professor Iacopi says. "Over time, we were able to achieve a reduction of more than 75% of the initial contact resistance.

"This means the electric signals being sent by the brain can be reliably collected and then significantly amplified, and that the sensors can also be used reliably in harsh conditions, thereby enhancing their potential for use in brain-machine interfaces."

The research is part of a larger collaboration to investigate how brainwaves can be used to command and control autonomous vehicles. The work is a partnership between Professor Iacopi, who is internationally acclaimed for her work in nanotechnology and electronic materials, and UTS Distinguished Professor Chin-Teng Lin, a leading researcher in brain-computer interfaces.

It is funded by $1.2 million from the Defense Innovation Hub.

If successful, the research will produce miniaturized, customized graphene-based sensors that have the potential for application in defense environments and beyond.