Study On The Mechanism And Performance Of Flexible Electroluminescence Driven By Triboelectric

Electroluminescence(EL)is a kind of non-thermal light generated by electric field,which attracted widespread attention in flexible intelligent displays,intelligent wearable,and electronic skin owing to its low power consumption,long service life and excellent mechanical stability compared with traditional LEDs.However,the high driving voltage required to emit light has potential risks for applications in the wearable.Simultaneously,it is significant to find a clean,efficient,and convenient energy source to get rid of the dependence on traditional energy sources as wearable electronic devices are gradually trending towards miniaturization,multi-functionality and diversification.Fortunately,triboelectric nanogenerators(TENG)based on triboelectrification and electrostatic induction coupling provides an effective solution to address energy problem,which effectively harvest mechanical energy from the environment at low frequencies,ushering in a new era of environmental energy harvesting and utilisation.In this paper,a self-driven electroluminescence system was designed by combining the excellent luminescence system of alternating current electroluminescence(ACEL)with efficient self-powered system of TENG.In addition,based on the limitations of conventional electrodes such as non-stretchable,a double network hydrogel was prepared as an electrode to achieve energy harvesting and sensing.The main research elements of the paper are as follows:(1)A wearable medical humidity and temperature monitoring system has been designed by combining ACEL device with TENG.The system generate an open circuit voltage of 160 V and a short circuit current of 6 μA by tapping the TENG at 1 Hz,which are sufficient to drive the ACEL device to achieve electroluminescence.Furthermore,the high voltage and low current generated by TENG is harmless for the body,broadening the application of ACEL device in wearable.(2)The paper proposed a double-network conductive hydrogel based on polyacrylamide(PAM)and polyvinyl alcohol(PVA)as stretchable electrode owing to the limitations of conventional electrodes,such as high rigidity and non-stretchability.The hydrogel exhibits superior tensile and electrical conductivity with a maximum elongation at break of 1540% and a tensile strength of 290 k Pa.(3)Benefiting from the excellent interpenetrating structure of the PAM-PVA double-network hydrogel,the stretchable TENG and ACEL device exhibit excellent output performance even in the stretched state,while the ACEL device emit uniform and stable green light over the stretching of 300%.(4)A self-driven raindrop characterisation system has been developed based on hydrogel and electroluminescence.The voltage magnitude of system is closely related to the amount of rainfall,which monitors rain droplet changes in real time,as well as visualizing luminescence and early warning,demonstrating the feasibility and enormous potential of the system for practical applications.