P–N junction-based ZnO wearable textile nanogenerator for biomechanical energy harvesting

Wearable nanogenerators have attracted intensive interest owing to their ability to convert the energy from body movement and the surrounding environment to electronic signals, which can power portable/wearable electronic devices for sensing, motion tracking or monitoring to improve the quality of human life. Herein, a p-n junction ZnO textile nanogenerator is successfully fabricated on conductive textiles utilising PEDOT:PSS/CuSCN-coated ZnO nanorods, combining the advantage of ZnO piezoelectricity and textile flexibility. It is found that by increasing the length of ZnO nanorods, the nanogenerators exhibit increasing output voltage and power density. The device with optimized ZnO nanorods length produces increasing output voltage from 0.2 V to 1.81 V as the shaking frequency increases from 19 Hz to 26 Hz, which can activate an LCD screen display. In addition, the device is able to generate increasing negative voltage from 1.64 V to 5.08 V by an increasing impacting force. Other mechanical forces such as flicking, gentle finger bending and tapping can also be harvested by the fabricated device. These results are of particular importance in designing future flexible self-powered devices and wearable electronics.