Researchers at the University of California San Diego have pioneered a breakthrough in wearable technology, transforming ordinary earbuds into sophisticated devices capable of recording brain activity and collecting sweat lactate data. These 3D screen-printed, flexible sensors not only detect electrophysiological signals from the brain but also analyze sweat lactate, an organic acid produced during exercise and metabolic processes. The proximity of sweat glands in the ear to the brain makes earbuds an ideal tool for gathering such data.

The primary motivation behind this innovative approach is the potential to diagnose different types of seizures. With over 30 distinct categories of seizures, each impacting specific brain regions, EEG data combined with sweat lactate measurements offers valuable diagnostic insights. Beyond medical applications, these biometric data points can enhance personal performance monitoring during exercise and provide valuable insights into stress levels and focus.

While in-ear biometric sensing is not entirely new, this sensor technology’s uniqueness lies in its ability to measure both brain activity and lactate levels. The researchers envision further refinement and development, leading to an era of everyday wearables equipped with neuroimaging sensors to collect health data. According to UC San Diego bioengineering professor Gert Cauwenberghs, the ability to measure both cognitive brain activity and metabolic states within a single, integrated in-ear device opens up vast possibilities for everyday health monitoring.

Overcoming various technical challenges was a crucial aspect of this sensor technology’s development. Researchers needed to create ultra-compact, thin sensors capable of collecting minute sweat samples. To accommodate the ear’s irregular shape, they incorporated bendable components, ensuring that the sensors maintained contact with the ear. The researchers designed spring-loaded, 3D-printed sensors that could adjust as earbuds moved, providing precise readings. These biometric sensors were also equipped with a hydrogel film to enhance sweat collection.

While these sensors currently require a substantial amount of sweat for meaningful data analysis, ongoing advancements promise increased precision. This means that, in the future, extensive physical exertion may not be necessary for insightful sweat analysis.

By Impact Lab