Flexible Alternating‐Current Electroluminescence Plunging to Below 1 Hz Frequency by Triboelectrification

Abstract Low frequency, portable power source is one of the key challenges for applications of wearable alternating‐current electroluminescent (ACEL) device because it typically requires a working frequency above 500 Hz. Here, an extremely low frequency self‐powered ACEL system is proposed, which consists of a vertical contact‐separation triboelectric nanogenerator and a self‐made flexible ACEL device. It achieves directly‐driven electroluminescence phenomenon in real‐time by triboelectrification and works completely self‐powered through converting kinetic energy of human body into electricity. The working frequency has fallen from 500 to 1 Hz, i.e., the real frequency needed for electroluminescence has dropped 500 times, which is due to the favorable low‐frequency high‐voltage advantages of the triboelectric nanogenerator. It delivers a stabilized open‐circuit voltage of 160 V and a short‐circuit current of 6 µA for applied force of 0.1 N. Meanwhile, a strong blueshift is also observed experimentally with the change of working frequency. Furthermore, a self‐powered medical protective gown is demonstrated that is real‐time monitoring both the temperature and humidity. This work breaking the bottleneck of high‐frequency driving, demonstrates the great potential of self‐powered ACEL systems in wearable electronics and medical health.