The Research Of Micro Energy Harvester With Unidirectional Output Characteristics

As a new micro/nano-energy harvester,the triboelectric nanogenerator(TENG)can be used to power the Internet of Things by harvesting environmental energy.It has been proved to be an extremely clean and sustainable power generation method,which has a promising development prospect.However,due to the intrinsic alternating-current(AC)output characteristics of the working process of TENG,an additional rectifier circuit must be employed to convert AC output into unidirectional current output in the practical application.The rectifier circuit not only reduces the efficiency of energy transfer from TENG to load but also makes TENG’s application process more complex,which greatly hinders the integration trend of TENG.Therefore,it is particularly urgent to research a TENG which can directly output unidirectional current to the load without any rectifying circuit.This thesis has presented and verified the working principle of a unidirectional-current triboelectric nanogenerator(UC-TENG),which has broken through the inherent AC output characteristics of traditional TENG.Then,three typical UC-TENG devices were designed and fabricated,and their practical application was demonstrated.The specific research points of the full text are as follows:By introducing the“lateral-electrode”structure,the current output direction of TENG is fixed as unidirectional,and thus the working principle of UC-TENG was proposed.After the verification though simulation,the corresponding device was designed and prepared based on the principle of UC-TENG.The test and demonstration of the device not only verified the reliability of the principle of UC-TENG but also demonstrated the advantages and potential application prospect of the unidirectional output characteristic of UC-TENG.The unidirectional-current triboelectric nanogenerator based on lateral-cantilevers(LC-TENG)was designed and fabricated by introducing the“lateral-cantilevers”.With the elasticity of the lateral-cantilevers,LC-TENG solved the problem of poor contact inside the UC-TENG device and improves the output performance of the UC-TENG.Through the simulation and testing,the working principle of LC-TENG was studied systematically,and the output waveform of the device was shown to be uniform and stable.The maximum open-circuit voltage,short-circuit current and power density of the device reached 300 V,1.4?A and 15.68 mW/m~2,respectively.Then,a promising application prospect of LC-TENG have been demonstrated by applying the prepared device to power the low-power electronic devices.Combining the proposed principle of UC-TENG with the traditional wind-cup structure,the unidirectional-current triboelectric nanogenerator based on the wind-cup(WC-TENG)was designed and prepared.The WC-TENG can keep the unidirectional current output in any wind direction,and the output power density was increased to 434mW/m~2.Based on the WC-TENG,a self-powered wireless environment monitoring system was proposed and demonstrated.The experimental results show that the system is very suitable for monitoring remote and harsh environment such as forests,oceans,grasslands,deserts,etc.Based on the research of UC-TENG,this thesis shows that the UC-TENGs have great attractive potentials to strengthen the integration capability of TENG to form all-in-one self-powered microsystems by simplifying the power management strategy,thus it is believed to promote TENG to make significant impacts to practical applications.