Non-contact triboelectric smart eye mask for ocular motion monitoring

Traditional sleep monitoring systems are often intrusive and uncomfortable due to direct skin contact, limiting long-term usability. To overcome this, we developed a non-contact smart eye mask using triboelectric nanogenerators for real-time ocular motion tracking. The device incorporates a double-layered composite film: a carbon nanotube-doped polymer charge-generation layer enhances initial electrical output, while a charge-trapping layer of reduced graphene oxide and molybdenum disulfide improves charge retention. The optimal material combination, identified through high-throughput simulations, was experimentally validated, leading to a high output voltage of 37.3 V. A unique triangle-shaped tribo-sensor array detects blinks, ocular motions, and captures subtle motions under closed eyelids, such as eyelid contractions during sleep, with clear signal differentiation. The system maintains reliable operation up to 20 mm away, enabling seamless integration into a wearable eye mask. This work offers a non-invasive, self-sustaining solution for sleep diagnostics and eye-controlled interfaces.