This paper details the utilisation of triboelectric nanogenerators (TENGs) to detect small
movements of the body. In this case, the movements of the eye behind the eyelids during rapid eye movement (REM) sleep.
An existing TENG configuration was adapted to be very sensitive to small movements via a spring like wire that enables the TENG to return to a neutral position more easily. It is sewn into a sleep mask for comfort during sleep. Each movement of the eye creates a small displacement thereby generating a small current through the TENG, which was amplified and filtered before being transmitted via Bluetooth low energy to a computer for further processing.
This paper demonstrates that TENGs can be effectively implemented to detect small movements of the eyeball under a closed eyelid, and further work is required before implementation in sleep studies is feasible.