Researchers from South Korea’s Kangwon National University have developed a self-healing sweat sensor device for monitoring health.

The sweatband can measure the presence of electrolytes in the wearer’s sweat and can heal itself in the event it is damaged during use.

To accomplish this, the team coated carbon fiber thread electrodes with a citric acid polymer. When severed, the threads immediately repaired themselves via the polymer’s hydrogen bonding. The threads, which are capable of detecting sodium and potassium, were sown into the headband along with a wireless electronic circuit board that delivers data to a corresponding smartphone.

During testing of the device, a volunteer wore the headband during an almost hour-long exercise session and it accurately tracked the wearer’s electrolyte concentrations and healed itself in just 20 seconds after the headband was cut.

This wearable device joins a host of other devices being launched under the wearable devices market. Some of the most recent iterations include wearable devices powered by wine as well as wearable devices designed for dogs and the elderly.

The study appears in the journal ACS Applied Materials and Interfaces.