Wind Energy Harvesting And Angle Sensing Studies Of Triboelectric Nanogenerators

Energy harvesting technology converts energy in the surrounding environment（such as light energy,heat energy,mechanical energy,etc.）into usable electrical energy.With the advancement of micro-nano technology and the application of new materials,the volume of energy harvesting devices has been continuously reduced and the efficiency has been continuously improved.Energy harvesting technology has been widely used in wireless sensor networks,wearable devices,smart homes and other fields.Triboelectric nanogenerator（TENG）is a novel energy harvesting technology that can efficiently convert ambient mechanical energy into electrical energy.The basic principle of TENG is to use the electrostatic friction effect between different materials to separate the charges on the surface of the materials,thereby generating electric energy.Due to its cost-effectiveness and robustness,it can be used to build self-powered sensing systems,providing new energy supply methods and sensing technology support for the development of intelligent devices.This thesis carried out the following research work:An all-fabric TENG flag was prepared.During the preparation process,the conductive cotton thread was made into a composite friction fiber by dip-coating method,which was woven into the main fabric TENG and the pump fabric TENG,and finally integrated into the whole TENG.The flag curls and twists under the action of wind,and the TENG works in a contact-separation mode of friction fibers.Under the wind speed of 3 m/s～12 m/s,the TENG flag outputs DC power,the open circuit voltage(V_oc)is 3 V～15 V,the short circuit current(I_sc)is 0.25μA～0.55μA,and the output power is 0.53 m W～3.136 m W.TENG flags have excellent flexibility,breathability,washability,no noise,and high durability of more than20,000 cycles.Under weak wind,the TENG flag has a friction frequency greater than 50 times per second,which has high energy harvesting efficiency.Therefore,the TENG flag in this study can be widely used in sign display,wind energy harvesting and wind speed sensing under various weather conditions.A hybrid louver consisting of TENG and solar cell arrays,which simultaneously has the function of harvesting ambient wind and solar energy,is investigated.The total size of the prepared louvers is 30 cm×17 cm,consisting of 8 aluminum（Al）-polytetrafluoroethylene（PTFE）-aluminum（Al）inductive TENGs and 8×3 arrays of polycrystalline silicon flexible solar cells.The 3 V open circuit voltage and 0.39 A short circuit current generated by the solar cell can drive electronic products such as thermometers and hygrometers to work.The TENG flag generated 320 V open-circuit voltage and 16μA short-circuit current at 12 m/s,which can simultaneously light up 200 LEDs.The electrode-dielectric-electrode induction structure can effectively collect low-speed wind as low as 1.5 m/s.The output performance of the TENG module is stable under 33,000 continuous wind tremors,and the power collection of the solar module can remain stable for a long time.This study demonstrates the application of the device in the louvers with TENG combined with solar cells for synchronous harvesting of wind and solar energy in Io T homes.The angle sensor based on inductive non-contact TENG self-powered technology is studied,and the angle sensing and monitoring system architecture of industrial robots is designed.The sensor adopts the non-contact TENG technology based on the electrostatic inductive coupling effect.By optimizing the multi-strip non-contact electrode structure,a high linearity of R²=0.99813 is achieved between the peak current and the rotational speed.When the sensor measures the rotation angle and angular velocity,it has high sensitivity of1.715 V/°and 0.132 V/°/s and high resolution of 3.6°and 45.324°/s,respectively.After50,000 cycles of open-circuit pulse voltage test,the average open-circuit voltage of the device is 10.59 V,the standard error is only 0.72 V,and the signal stability is extremely high.In addition,the sensor achieves adjustable resolution by adjusting the gear ratio,which can effectively amplify the angular rotation characteristics.Based on this device,we implemented a sports rehabilitation detection system,and made its performance more stable and reliable by simplifying the signal processing circuit.