Bioengineers and cognitive scientists at the University of California, San Diego, have built a portable, 64-channel wearable brain activity monitoring system. The technology features dry EEG sensors that are easier to apply than wet sensors.

The headset features 64 channels for EEG monitoring.
(Credit: Jacobs School of Engineering/UC San Diego)

The headset and sophisticated software suite have applications in research, neuro-feedback, and clinical diagnostics. In the future, scientists envision a world where neuroimaging systems work with mobile sensors and smartphones to track brain states throughout the day and augment the brain’s capabilities.

The EEG headset has an octopus-like form, in which each arm is elastic, so that it fits on many different kinds of head shapes. The sensors at the end of each arm are designed to make optimal contact with the scalp while adding as little noise in the signal as possible.

Sensors designed to work on a subject’s hair are made of a mix of silver and carbon deposited on a flexible substrate. A silver/silver-chloride coating allows sensors to remain flexible and durable while still conducting high-quality signals.

Sensors designed to work on bare skin are made from a hydrogel encased inside a conductive membrane. The sensors are mounted inside a pod equipped with an amplifier, which helps boost signal quality while shielding the sensors from interferences from electrical equipment and other electronics.

Next steps include improving the headset’s performance while subjects are moving. The device can reliably capture signals while subjects walk but less so during more strenuous activities such as running. Electronics also need improvement to function for longer time periods—days and even weeks instead of hours.