Research For Wind Energy Harvesting Based On Films Flapping Triboelectric Nanogenerator

With the rapid development of Internet of things and Internet technology,the demand of sensors is increasing.To realize the real-time monitor,data collection and transmission of the environment,wireless sensors are highly needed for resource development and environmental monitoring in remote areas or open sea areas.However,the traditional way of power supply for wireless sensor is mostly batteries or solar panels,which is generally expensive,especially the way of battery power supply,with limited service life and non-recyclability,which has a bad impact on the environment.Therefore,we should consider how to collect energy from the environment to realize the self-power of wireless sensor.Wind energy,a clean energy,widely distributed and easy to be collected,is an ideal energy source for wireless sensor.At present,the method of wind energy acquisition is mainly based on the large-scale wind turbine based on the principle of electromagnetic induction,which is basically on the megawatt level or more.With high output power,but not suitable for small wireless sensors,whose power consumption is basically on the micro to milli watt.Therefore,the miniaturization and self-power of wireless sensor is a feasible solution,which will also be the focus of this paper.Since Prof.Zhonglin Wang proposed the Triboelectric Nanogenerator(TENG)in 2012,as a new and cutting-edge direction,it has become one of the hot spots in academic research,and its application in the field of self-power and sensors has been widely valued.TENG is based on the coupling of friction electrification and electrostatic induction.Due to the different materials triboelectric sequence,static electricity will be generated when contacting with friction,electrostatic field is formed,and driving the charges transfer between the electrodes.The periodic relative displacement of the friction pair will change the intensity of the electric field,forming alternating electric field and current.Therefore,TENG can effectively convert the mechanical energy into electrical energy,to realize the power supply for the sensor.In this paper,based on the contact free standing layer TENG,the Films Flapping Triboelectric Nanogenerator(FF-TENG)is proposed to collect wind energy,and used as sensor or power supply for it in the environment.Coupling the TENG and wind-induced vibration,and combine with their working principles,with the experiment and analysis of parameters such as wind speed,film length and film number,the wind energy collection is effectively realized,and the feasibility of energy supply for wireless sensor nodes is provided.The main research contents and conclusions of this paper are as follows:Firstly,this paper analyzes the theory of FF-TENG and the film flapping principle.Some main parameters that affects the power output performance are determined,which lays a theoretical basis for the design of the experiment and the interpretation of the results.In addition,the flow field visualization experiment of the flapping film is carried out to understand the output characteristics of the FF-TENG in this paper.Secondly,based on in-depth study of the existing wind energy harvest technology,a film flapping triboelectric nanogenerator is proposed to collect the wind energy,and some main parameters are analyzed by experiments.It is found that with the increase of wind speed,for a certain film,the output voltage and transfer charge of the device increase with the wind speed.When the wind speed reaches to?4.74m/s,the two output signals will no longer increase or decrease significantly,but in a fluctuating state.The short-circuit current increases with the increase of wind speed.For a certain wind speed,with the increase of the film length,the output voltage and the transferred charge increase both,and the short-circuit current tends to be stable when the film length reaches a certain value.Thirdly,based on the single film FF-TENG,the model with double-and multi-films are put forward,which has not been put forward before.The unique performance and characteristics of this model are also found through the experiment.The results show that the outputs of the downstream film are better than that of the upstream film and the single film.Their flapping frequency is almost the same.In addition,the output characteristics of the FF-TENG with multiple films(up to four tandem films)are studied.Through the analysis and comparison of the output electric signals of each film,it is found that the electric performance of the trailer film is higher than the leader films,and their flapping frequency is basically the same.At last,the demonstration experiment of the optimized generator is carried out to verify its capacity and performance.The output power of the double film under different circuit connection is tested.The maximum output power is 167.8mW,the output voltage is 1.87 times of the 80mm single film and 1.45 times of the 160mm single film,which effectively improves the power generation efficiency.And the excellent output performance is demonstrated with 304 LEDs lighted,which shows that the device can provide sufficient and stable energy for the electric unit under some conditions.