A team of researchers from the University of Technology Sydney's Faculty of Engineering and IT has created a biosensor that clings to the skin of the face and head to detect electrical signals transmitted by the brain. Then, these signals are translated into commands to control autonomous robotic systems.
The novel biosensor has overcome three major challenges of graphene-based biosensing: corrosion, durability, and skin contact resistance. This is thanks to the sensor's construction, which consists of many layers of very thin, very strong carbon grown directly onto a silicon-carbide-on-silicon substrate.
"We’ve been able to combine the best of graphene, which is very biocompatible and very conductive, with the best of silicon technology, which makes our biosensor very resilient and robust to use,” explained Professor Francesca Iacopi, who developed the biosensor with her team.
But first, let's take a step back and define what biosensors are. A biosensor is a device that measures biological or chemical processes by generating signals proportional to an analyte concentration in the reaction, thus diagnosing diseases. This allows for appropriate management and therapy. Graphene is commonly employed in the development of biosensors; nevertheless, it has limitations because many of these devices were designed for single-use applications and are prone to delamination when in touch with perspiration and other kinds of moisture on the skin.
By contrast, the UTS biosensor can be used for prolonged periods and reused multiple times, even in highly saline environments – an unprecedented result. Further, 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.
The novel biosensor, on the other hand, can be used for extended periods of time and reused multiple times, even in very saline settings. It's because of these reasons that it was called "an unparalleled finding" in the press release. Also, skin contact resistance, a problem that occurs when the sensor is not in optimal contact with skin, has been found to be greatly reduced by the sensor.
“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," explained Professor Iacopi.