Triboelectric Nanogenerators Based On Flow-induced Vibration For Breeze Wind Energy Harvesting And Monitoring

With the development of society,the demand for energy is increasing,and electricity has become a necessity.While traditional energy is promoting social progress and civilization,its consumption is also increasing,and the negative effects have been revealed.Traditional energy is not only nonrenewable,but also carbon dioxide emissions from fossil fuels accelerate global warming,etc.Faced with these problems,people have a sense of crisis,looking at the renewable energy which does not produce or rarely produces pollutants,such as solar energy,wind energy,geothermal energy,biological energy,etc.Based on the principle of triboelectrification and electrostatic induction,triboelectric nanogenerator(TENG)was proposed in 2012.TENGs are dedicated to collecting irregular,low-frequency and distributed mechanical energy and converting it into electrical energy to continuously power small electronic devices.TENGs also expand its application in self-powered sensors.Based on the advantages of low-cost,easy to manufacture and wide adaptability,TENGs have become one of the hot research fields,and its advantages are highlighted in the collection and utilization of a series of renewable energy including wind energy,marine energy etc.In this paper,based on the triboelectric nanogenerator technology and flow induced vibration,combined with the characteristics of natural environment wind,to effectively collect wind energy and realize self-powered sensing and monitoring as the fundamental purpose,the wind energy collection and monitoring devices based on flow induced vibration were designed,which provides a reliable idea for the potential application of self-powered wind energy sensing system in wireless environmental monitoring network.The main research work and conclusions are as follows(1)A flutter effect based triboelectric nanogenerator(FE-TENG)with contact separation mode is mainly composed of two parts:wind drive part and TENG unit part.In order to optimize the output,reduce the starting wind speed and achieve fast response,we test the influence of FE-TENG parameters on the electrical output.Under the optimal conditions,with the wind speed of 4.5 m/s,the instantaneous power of a FE-TENG unit reaches a maximum of 4 m W(volume power density～1.36 W/m~3)at a matching load of58 MΩ,the circuit voltage can reach about 281 V,the short-circuit current is about 13.4μA,and the charge is about 143 n C.Based on the good linear relationship between wind speed and electrical output signal,we created a platform based on Lab VIEW software to realize self-powered sensing for monitoring low wind speed data.The results show that FE-TENG has high sensitivity(～12.1 V/(m/s))and fast response to wind.This work provides a better method to solve the problems of energy loss of triboelectric nanogenerator for collecting wind energy.(2)The interaction between tower shaped triboelectric nanogenerator based on flow induced vibration(T-TENG)and fluid was analyzed theoretically.The contact state of T-TENG was optimized by theoretical directivity to achieve the maximum energy conversion efficiency.At wind speed of 4.3 m/s,the instantaneous power of a T-TENG unit reaches a maximum of 1.46 m W(volume power density～2.10 W/m~3)at a matching load of 50 MΩ,the average peak value of short circuit current is about 10μA,the average peak value of open circuit voltage is about 199 V,and the average peak value of transferred charge is about 91 n C.Based on the random and multi-directional characteristics of the wind,we set up a multi-T-TENG unit around to divide the wind direction precisely,and realized the wind direction visualization based on T-TENG.Furthermore,based on the good linear relationship between open circuit voltage and wind speed,we built the wind speed and direction sensing system platform of Lab VIEW software,and completed the construction of self-powered forest meteorological station.Finally,as an important factor in practical application,the mechanical durability of T-TENG was evaluated,and the standardized output only decreased by 4%after 100K cycles.This work further expands the application platform of FE-TENG and shows the potential application of self-powered wind sensor system in wireless environmental monitoring network.