Study On Energy And Signal Acquisition Methods Of Triboelectric Nanogenerator

Self-powered sensing has become a trend since it was proposed.Triboelectric Nanogenerator(TENG),based on triboelectric and electrostatic induction is one of the most promising self-powered sensing technologies,is expected to be an effective energy supply and sensing method for wireless sensor nodes,which could solve the problems of short life-span and difficult maintenance of traditional battery-powered.In recent years,a large number of studies have shown the potential of TENG in self-powered systems.TENG can be used not only as an energy harvester to convert various mechanical energy in environment into electrical energy,but also as active sensor to convert the information in the environment into electrical signals.However,the electrical output of TENG has the characteristics of high voltage,high impedance and low current,making it difficult to extract energy or obtain information from it.It'worse for obtaining both energy and information from a single device.This thesis researched on the simultaneous acquisition of signal and energy output by TENG,which put forward the idea of using a single TENG as energy harvesting and signal sensing at the same time or separately,then designed and verified the related energy and signal acquisition method.The main work of the thesis includes:(1)The electrical characteristics of signal measurement are studied for the four kinds of electrical signals output when TENG is used for signal sensing,including voltage,current,charge and frequency,and the conditions that need to be met when measuring these four signals are analyzed.Corresponding measurement circuits are proposed for the four types of signal measurements,and the conditions that the corresponding measurement circuits need to meet and the corresponding error estimation methods are studied through theoretical analysis.The experimental results show that when the designed signal measurement circuit is used to measure the TENG output signal,the error can reach about 5%,preferably within 1%.(2)In order to improve the energy extraction efficiency of TENG for energy harvesting,research and analysis have been done on serveral aspects of TENG energy harvesting power management.Firstly,the characteristics of various rectification and primary storage circuits including full-wave rectification,half-wave rectification,and Benent's doubler are studied.The respective advantages and ranges of them are summarized and compared.Then,based on the idea of maximizing energy harvesting efficiency per unit time,an optimal design and analysis method for secondary energy transfer is proposed,which is verified by experiments.A self-adaptive energy release strategy is proposed.When the power is s?ficient,the electrical energy is released to the load regularly,which can ensure the stable work of the load.(3)In order to make full use of the excellent output characteristics of TENG devices,the idea of using a single TENG device for energy harvesting and signal sensing at the same time was proposed.The method of extracting energy and frequency signals from TENG at the same time was studied,and corresponding circuit system were proposed.Then we successfully demonstrated the use of R-TENG to measure rotational speed/wind speed while obtaining energy from rotation to power the measurement system.The demonstration system can work continuously at a speed of600 rpm with a wireless data transmission frequency of once/128 s,which does not require external power supply.(4)In order to further obtain energy and voltage signals from a single TENG device,a time-division multiplexing energy and signal management strategy is proposed and researched.Corresponding circuit system is designed,including signal acquisition and energy management,and the circuit can switch TENG to energy channel or signal channel automaticly.Taking an acceleration sensing system based on LS-TENG as a demonstration example,the measurement of the output voltage signal of LS-TENG is realized.The voltage measurement accuracy can reach up to 0.9%,and energy can be obtained from LS-TENG to replenish power for the system during the interval of signal measurement.The LS-TENG could charge a 5m Ah rechargeable battery from voltage of900 m V to 1V under experimenter's manually shake in 1000s.