The latest concept for a wearable brain interface lets users place electrodes and steer robots or other devices using what could be described as mind power, all without applying wet gels on the scalp. This development was highlighted by the American Chemical Society.
In the last few years, scientists have learned to monitor brain activity with electroencephalography. When signals from the brain are captured, users can influence on-screen information or even direct robotic movement. The highest effectiveness, however, appears when electrodes sit inside the skull. That setup is obviously invasive, so researchers previously tried to apply electrodes on the skin, which required conductive gel to ensure good contact. The gel adds a mess and a wait time to the process, and it can wear off over minutes or hours.
Francesca Jakopi and her team have introduced a dry sensor for reading brain signals that matches the performance of the traditional wet approach. The sensor relies on polycrystalline graphene and features electrodes molded into three dimensional shapes to maximize contact with the skin. Among the shapes tested, a hexagonal pattern performed best on the scalp area at the back of the head where the occipital region lies, near the base of the skull connected to the visual cortex. The researchers integrated eight of these sensors into a flexible headband designed to sit at the rear of the head. When paired with an augmented reality headset that presents visual cues, the system could discern which cues were being shown. After calibration, the headband translated the reading of brain signals into commands that the computer used to drive a quadrupedal robot.
Although the dry sensors do not yet outperform the wet version in every metric, the team expects ongoing refinements will yield a fully operational helmet that communicates with the brain without gel. The vision is to deliver a practical, gel-free brain control helmet that can support broader use in research, medicine, and assistive technology. [Attribution: American Chemical Society]”