Smart Contact Lens Detects Stress Through Serotonin in Tears
Lab on a Contact Lens Can Measure Stress Through Serotonin
A new hydrogel contact lens with printed graphene and silver electrodes can measure serotonin in tears at concentrations as low as 72 trillionths of a mole per liter. In tests, serotonin levels dropped after volunteers performed stressful tasks, and the lens worked on a live pig's eye without irritation. The team also built a wireless NFC version, though more safety and validation work is needed.
Tears could become a practical, noninvasive source of biochemical information that can be measured repeatedly over time.